WorldWideScience

Sample records for cancer seeking biomolecules

  1. Intention to seek information on cancer genetics

    Directory of Open Access Journals (Sweden)

    J.E. Andrews

    2005-01-01

    Full Text Available Objective. The public has a high interest in seeking personal genetic information, which holds implications for health information seeking research and health care policy. Rapid advances in cancer genetics research promise early detection, prevention and treatment, yet consumers may have greater difficulty finding and using the information they may need to make informed decisions regarding their personal health and the future of their families. Design. A statewide telephone survey was conducted of non-institutionalized Kentucky residents 18 years of age or older to investigate factors associated with the intention to seek cancer genetics information, including the need for such information seeking help. Results. The results show that intention to seek cancer genetics information, if testing were readily available, is moderately high (62.5% of those responding; n=835, and that status as a racial minority, the perception that cancer runs in one's family, and frequent worrying about cancer risk are statistically significant predictors of intent to seek genetics information. Conclusion. . We argue that an already complex health information environment will be even more difficult for individuals to navigate as genetic research becomes more ubiquitous in health care. An increase in demand for genetics information in various forms, as suggested by these results and those of other studies, implies that enduring intervention strategies are needed to help individuals acquire necessary health information literacy skills, with special attention given to racial minorities.

  2. Why Breast Cancer Patients Seek Traditional Healers

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    Mazanah Muhamad

    2012-01-01

    Full Text Available Traditional healing is a common practice in low and middle income countries such as Malaysia. Eighty percent of Malaysians consult traditional healers or “bomoh” at some time in their life for health-related issues. The purpose of our study was to explore why breast cancer patients visit traditional healers. This is a qualitative study utilizing in-depth interviews with 11 cancer survivors who sought both traditional and Western medicine. The findings revealed the following reasons for which patients seek traditional healers: (1 recommendation from family and friends, (2 sanction from family, (3 perceived benefit and compatibility, (4 healer credibility, and (5 reservation with Western medicine and system delay. These factors work together and are strongly influenced by the Malaysian cultural context. The issue with the Western health system is common in a developing country with limited health facilities.

  3. Polyoxometalate-biomolecule conjugates: a new approach to create hybrid drugs for cancer therapeutics.

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    Yang, Hai-Kuan; Cheng, Yi-Xing; Su, Ming-Ming; Xiao, Yu; Hu, Min-Biao; Wang, Wei; Wang, Qian

    2013-03-01

    Some polyoxometalate (POM) clusters have demonstrated attractive anticancer properties. Unfortunately, their cytotoxicity upon normal cell is one of fateful side effects obstructing their further clinic application as inorganic drugs. In this communication, we report a new approach to create hybrid drugs potentially for cancer therapeutics. At first, the POM cluster bioconjugates were created by attaching the bioactive ligands on an amine grafted POM via simple amidation reaction. The cytotoxicity study with breast cancer cells (MCF-7 and MDA-MB-231) and non-cancerous breast epithelial cell (MCF-10A) showed that rationally selected ligands with cancer-cell targeting ability on POM-biomolecule conjugates can impart enhanced anti-tumor activity and selectivity, thus representing a new concept to develop novel POM-biomolecule hybrid drugs with the potential synergistic effect: increased bioactivity and lower side effect.

  4. Health Information Seeking and Cancer Screening Adherence Rates.

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    Shneyderman, Yuliya; Rutten, Lila J Finney; Arheart, Kristopher L; Byrne, Margaret M; Kornfeld, Julie; Schwartz, Seth J

    2016-03-01

    Effective screening tools are available for many of the top cancer killers in the USA. Searching for health information has previously been found to be associated with adhering to cancer screening guidelines, but Internet information seeking has not been examined separately. The current study examines the relationship between health and cancer Internet information seeking and adherence to cancer screening guidelines for breast, cervical, and colorectal cancer in a large nationally representative dataset. The current study was conducted using data from the Health Information National Trends Survey from 2003 and 2007. The study examined age-stratified models which correlated health and cancer information seeking with getting breast, cervical, and colorectal cancer screening on schedule, while controlling for several key variables. Internet health and cancer information seeking was positively associated with getting Pap screening on schedule, while information seeking from any sources was positively associated with getting colorectal screening on schedule. People who look for health or cancer information are more likely to get screened on schedule. Some groups of people, however, do not exhibit this relationship and, thus, may be more vulnerable to under-screening. These groups may benefit more from targeted interventions that attempt to engage people in their health care more actively.

  5. GPs' management of women seeking help for familial breast cancer

    NARCIS (Netherlands)

    de Bock, GH; Vlieland, TPMV; Hakkeling, M; Kievit, J; Springer, MP

    1999-01-01

    Objective. We aimed to ascertain how often patients seek help for familial breast cancer in primary care, and to identify GPs management of these patients, in order to see whether guidelines are followed. Methods. This was a descriptive study. GPs (n = 202) attending a postgraduate education program

  6. Symptom interpretation and health care seeking in ovarian cancer

    DEFF Research Database (Denmark)

    Seibaek, Lene; Petersen, Lone K; Blaakær, Jan

    2011-01-01

    with ovarian cancer. These results were combined with findings from semi-structured qualitative research interviews on women's bodily experiences with symptom development. RESULTS: A number of 663 Danish women with ovarian cancer attended 27 different kinds of primary health care providers in a total of 14......BACKGROUND: Ovarian cancer is the leading cause of death among women suffering from gynaecological malignancies in the Western world. Worldwide, approximately 200,000 women are diagnosed with the disease each year. This article deals with the health care seeking and symptom interpretation process...... among Danish women, who have a very high mortality rate. METHODS: The health seeking and symptom interpretation process was analysed via combining study methods. The material consisted of registry data dealing with the use of public health care and hospital services of Danish women, newly diagnosed...

  7. Cancer Fatalism, Literacy, and Cancer Information Seeking in the American Public

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    Kobayashi, Lindsay C.; Smith, Samuel G.

    2016-01-01

    Information seeking is an important behavior for cancer prevention and control, but inequalities in the communication of information about the disease persist. Conceptual models have suggested that low health literacy is a barrier to information seeking, and that fatalistic beliefs about cancer may be a mediator of this relationship. Cancer…

  8. Understanding barriers to Malaysian women with breast cancer seeking help.

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    Norsa'adah, Bachok; Rahmah, Mohd Amin; Rampal, Krishna Gopal; Knight, Aishah

    2012-01-01

    Delay in help-seeking behaviour which is potentially preventable has a major effect on the prognosis and survival of patients with breast cancer. The objective of this study was to explore reasons for delay in seeking help among patients with breast cancer from the East Coast of peninsular Malaysia. A qualitative study using face- to-face in-depth interview was carried out involving 12 breast cancer patients who had been histo-pathologically confirmed and were symptomatic on presentation. Respondents were selected purposely based on their history of delayed consultation, diagnosis or treatment. All were of Malay ethnicity and the age range was 26-67 years. Three were in stage ll, seven in stage lll and two in stage lV. At the time of interview, all except one respondent had accepted treatment. The range of consultation time was 0.2-72.2 months with a median of 1.7 months, diagnosis time was 1.4-95.8 months( median 5.4 months )and treatment time was 0-33.3 months (median 1.2 months). The themes derived from the study were poor knowledge or awareness of breast cancer, fear of cancer consequences, beliefs in complementary alternative medicine, sanction by others, other priorities, denial of disease, attitude of wait and see and health care system weakness. Help-seeking behaviour was influenced by a complex interaction of cognitive, environmental, beliefs, culture and psycho-social factors. Breast cancer awareness and psychological counselling are recommended for all patients with breast symptoms to prevent delay in seeking clinical help.

  9. Looking beyond the Internet: examining socioeconomic inequalities in cancer information seeking among cancer patients.

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    Lee, Chul-Joo; Ramírez, A Susana; Lewis, Nehama; Gray, Stacy W; Hornik, Robert C

    2012-01-01

    The gap in cancer information seeking between high-socioeconomic-status (high-SES) cancer patients and low-SES cancer patients deserves serious attention, considering the importance of information and knowledge in cancer control. We thus explored the association of SES, as measured by education, with cancer patients' overall cancer information seeking, and with seeking from each source (i.e., the Internet, mass media, medical sources, and nonmedical interpersonal sources) and across two topic categories (i.e., treatment, quality of life). We then asked whether the effect of education on treatment information seeking is reduced among those who are particularly motivated to control treatment choices. We conducted a survey with breast, prostate, and colon cancer patients diagnosed in 2005 (n = 2,013), who were randomly drawn from the Pennsylvania Cancer Registry in the fall of 2006. We found that education was more strongly associated with Internet use than with the use of other sources regardless of topics. Also, when information was sought from mass media, education had a greater association with treatment information seeking than with quality-of-life information seeking. Preference for active participation in treatment decision making, however, did not moderate the effect of education on treatment information seeking. The implications of these findings for public health research and cancer patient education were discussed.

  10. Association of eHealth literacy with cancer information seeking and prior experience with cancer screening.

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    Park, Hyejin; Moon, Mikyung; Baeg, Jung Hoon

    2014-09-01

    Cancer is a critical disease with a high mortality rate in the US. Although useful information exists on the Internet, many people experience difficulty finding information about cancer prevention because they have limited eHealth literacy. This study aimed to identify relationships between the level of eHealth literacy and cancer information seeking experience or prior experience with cancer screening tests. A total of 108 adults participated in this study through questionnaires. Data covering demographics, eHealth literacy, cancer information seeking experience, educational needs for cancer information searching, and previous cancer screening tests were obtained. Study findings show that the level of eHealth literacy influences cancer information seeking. Individuals with low eHealth literacy are likely to be less confident about finding cancer information. In addition, people who have a low level of eHealth literacy need more education about seeking information than do those with a higher level of eHealth literacy. However, there is no significant relationship between eHealth literacy and cancer screening tests. More people today are using the Internet for access to information to maintain good health. It is therefore critical to educate those with low eHealth literacy so they can better self-manage their health.

  11. Symptom interpretation and health care seeking in ovarian cancer

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    Blaakaer Jan

    2011-06-01

    Full Text Available Abstract Background Ovarian cancer is the leading cause of death among women suffering from gynaecological malignancies in the Western world. Worldwide, approximately 200,000 women are diagnosed with the disease each year. This article deals with the health care seeking and symptom interpretation process among Danish women, who have a very high mortality rate. Methods The health seeking and symptom interpretation process was analysed via combining study methods. The material consisted of registry data dealing with the use of public health care and hospital services of Danish women, newly diagnosed with ovarian cancer. These results were combined with findings from semi-structured qualitative research interviews on women's bodily experiences with symptom development. Results A number of 663 Danish women with ovarian cancer attended 27 different kinds of primary health care providers in a total of 14,009 visits during 2007. The women also had 6,214 contacts with various hospitals, and obtained 562 different diagnoses. From the main theme "Women's experiences with the onset of symptoms" three sub-themes were identified: "Bodily sensations", "From bodily sensation to symptom", and "Health seeking and treatment start". In all cases the General Practitioner represented the first contact to public health care, acting as gate-keeper to specialist and hospital referral. The women were major users of public health care throughout the diagnostic process and subsequent treatment. All women held personal knowledge concerning the onset of their symptoms. The early symptoms of ovarian cancer might be uncharacteristic and non-disease-specific when interpreted as personal experiences, but they had similarities when analysed together. Conclusions Diagnostic delay in ovarian cancer seems far from being exclusively a medical problem, as the delay proved to be influenced by organisational, cultural, and social factors, too. Initiatives facilitating the diagnostic

  12. Stigma and On-line Health Information Seeking of U.S. South Asian Cancer Survivors.

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    George, Sheba M; Kagawa Singer, Marjorie

    2015-01-01

    The internet has replaced physicians as primary health information source for cancer-survivors.It is important to uncover barriers/facilitators to cancer information seeking, particularly on-line.Asian Americans are the fastest growing U.S racial/ethnic minority, 2) cancer is the leading cause of r death and 3) cancer knowledge is low among them and little research is done on their cancer information seeking strategies. This study aims to examine qualitatively cancer information-seeking patterns of the Asian American group, South Asians, using in-depth interview methods. Family members and social networks are highly engaged in providing informational support to South Asian cancer survivors. such collaborative information seeking is limited by stigma related to cancer and must be taken into consideration when developing culturally appropriate cancer health information seeking interventions in such communities.

  13. Cancer Fatalism, Literacy, and Cancer Information Seeking in the American Public.

    Science.gov (United States)

    Kobayashi, Lindsay C; Smith, Samuel G

    2016-08-01

    Information seeking is an important behavior for cancer prevention and control, but inequalities in the communication of information about the disease persist. Conceptual models have suggested that low health literacy is a barrier to information seeking, and that fatalistic beliefs about cancer may be a mediator of this relationship. Cancer fatalism can be described as deterministic thoughts about the external causes of the disease, the inability to prevent it, and the inevitability of death at diagnosis. This study aimed to examine the associations between these constructs and sociodemographic factors, and test a mediation model using the American population-representative Health Information and National Trends Survey (HINTS 4), Cycle 3 (n = 2,657). Approximately one third (34%) of the population failed to answer 2/4 health literacy items correctly (limited health literacy). Many participants agreed with the fatalistic beliefs that it seems like everything causes cancer (66%), that one cannot do much to lower his or her chances of getting cancer (29%), and that thinking about cancer makes one automatically think about death (58%). More than half of the population had "ever" sought information about cancer (53%). In analyses adjusted for sociodemographic characteristics and family cancer history, people with limited health literacy were less likely to have ever sought cancer information (odds ratio [OR] = 0.63; 0.42-0.95) and more frequently endorsed the belief that "there's not much you can do . . ." (OR = 1.61; 1.05-2.47). This fatalistic belief partially explained the relationship between health literacy and information seeking in the mediation model (14% mediation). Interventions are needed to address low health literacy and cancer fatalism to increase public interest in cancer-related information.

  14. Biomolecule-loaded chitosan nanoparticles induce apoptosis and molecular changes in cancer cell line (SiHa).

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    Sujima Anbu, Anbu; Velmurugan, Palanivel; Lee, Jeong-Ho; Oh, Byung-Taek; Venkatachalam, Perumal

    2016-07-01

    The present study reports on the synthesis of chitosan nanoparticles (CNPs) using methanol extracts of Gymnema sylvestre (GS) leaves and Cinnamomum zeylanicum (CZ) bark. Biomolecule-loaded nanoparticles induced apoptosis in a human cervical cancer (SiHa) cell line, and experiments were carried out to elucidate the underlying molecular mechanisms. FT-IR and XRD showed possible functional groups of the biomolecules and the crystalline nature of CNPs, respectively. Transmission electron microscopy images revealed that synthesized GSCNPs and CZCNPs had a smooth spherical shape with average sizes of about 58-80 and 60-120nm, respectively. Dynamic light scattering studies indicated that both GSCNPs and CZCNs were structurally stable with homogenous and heterogeneous natures, respectively. Furthermore, synthesized GSCNPs and CZCNPs exhibited dose-dependent cytotoxicity against the SiHa cancer cell line, with inhibitory concentration (IC50) values of 102.17μg/ml, 87.75μg/ml, 132.74μg/ml and 90.35μg/ml for GS leaf extract, GSCNPs, CZBE and CZCNPs, respectively.

  15. Treatment with bone-seeking radionuclides for painful bone metastases in patients with lung cancer

    DEFF Research Database (Denmark)

    Zacho, Helle D; Karthigaseu, Nita Nishanthiny; Fuglsang, Randi

    2017-01-01

    Treatment with bone-seeking radionuclides may provide palliation from pain originating from bone metastases. However, most studies have been conducted in patients with prostate cancer and patients with breast cancer. We aimed to perform a systematic review of the use of radionuclide treatment...

  16. Cancer information-seeking behaviors and information needs among Korean Americans in the online community.

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    Park, Hyejin; Park, Min Sook

    2014-04-01

    Korean Americans tend to have less access to health service and cancer screening tests than all US population. It is necessary to understand their current cancer information-seeking behaviors and information needs to more effectively provide adequate cancer information. However, there is little known about their cancer information seeking behaviors and needs. The purpose of the study was to understand cancer information seeking behaviors and information needs among Korean Americans. Data were collected from MissyUSA, which is one of the biggest websites for the Korean community in the USA. A total of 393 free-texts from January to June 2013 were reviewed; 120 were deleted because the messages were not related to cancer health information. A total of 273 posted free-texts were analyzed for this study, using an open source text-mining software program called AntConc 3.2.4. The extracted terms were categorized based on coding systems, after linguistic variations were handled. Terms such as "surgery," "breast cancer," "examination," "cancer" (unspecified), "Korea," and "pain" were most frequently identified. Medical topics accounted for 71.4 % of the main topics of the postings. Treatment was the most frequently discussed in the medical topics while in the non-medical category, the most frequently discussed topic was recommendations for hospitals or doctors. In relation to types of cancer, breast cancer was the greatest concern, followed by cervical and liver cancer. The findings from this study can help in establishing more effective strategies to provide better cancer information among Korean Americans by assessing their cancer information seeking trends and information needs.

  17. Meta-synthesis exploring barriers to health seeking behaviour among Malaysian breast cancer patients.

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    Yu, Foo Qing; Murugiah, Muthu Kumar; Khan, Amer Hayat; Mehmood, Tahir

    2015-01-01

    Barriers to health seeking constitute a challenging issue in the treatment of breast cancer. The current meta- synthesis aimed to explore common barriers to health seeking among Malaysian breast cancer patients. From the systematic search, nine studies were found meeting the inclusion criteria. Data extraction revealed that health behavior towards breast cancer among Malaysia women was influenced by knowledge, psychological, sociocultural and medical system factors. In terms of knowledge, most of the Malaysian patients were observed to have cursory information and the reliance on the information provided by media was limiting. Among psychological factors, stress and sense of denial were some of the common factors leading to delay in treatment seeking. Family member's advice, cultural beliefs towards traditional care were some of the common sociocultural factors hindering immediate access to advanced medical diagnosis and care. Lastly, the delay in referral was one of the most common health system-related problems highlighted in most of the studies. In conclusion, there is an immediate need to improve the knowledge and understanding of Malaysian women towards breast cancer. Mass media should liaise with the cancer specialists to disseminate accurate and up-to-date information for the readers and audience, helping in modification of cultural beliefs that hinder timing health seeking. However, such intervention will not improve or rectify the health system related barriers to treatment seeking. Therefore, there is an immediate need for resource adjustment and training programs among health professional to improve their competency and professionalism required to develop an efficient health system.

  18. Cancer Information Seeking Among Adult New Zealanders: a National Cross-Sectional Study.

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    Richards, Rosalina; McNoe, Bronwen; Iosua, Ella; Reeder, Anthony; Egan, Richard; Marsh, Louise; Robertson, Lindsay; Maclennan, Brett; Dawson, Anna; Quigg, Robin; Petersen, Anne-Cathrine

    2016-11-16

    Organisations seeking to establish themselves as leading cancer information sources for the public need to understand patterns and motivators for information seeking. This study describes cancer information seeking among New Zealanders through a national cross-sectional survey conducted in 2014/15 with a population-based sample of adults (18 years and over). Participants were asked if they had sought information about cancer during the past 12 months, the type of information they sought, what prompted them to look for information and ways of getting information they found helpful. Telephone interviews were completed by 1064 participants (588 females, 476 males, 64% response rate). Of these, 33.8% of females and 23.3% of males (total, 29.2%) had searched for information about cancer over the past year. A search was most frequently prompted by a cancer diagnosis of a family member or friend (43.3%), a desire to educate themselves (17.5%), experience of potential symptoms or a positive screening test (9.4%), family history of cancer (8.9%) or the respondent's own cancer diagnosis (7.7%). Across the cancer control spectrum, the information sought was most commonly about treatment and survival (20.2%), symptoms/early detection (17.2%) or risk factors (14.2%), although many were general or non-specific queries (50.0%). The internet was most commonly identified as a helpful source of information (71.7%), followed by health professionals (35.8%), and reading material (e.g. books, pamphlets) (14.7%).This study provides a snapshot of cancer information seeking in New Zealand, providing valuable knowledge to help shape resource delivery to better meet the diverse needs of information seekers and address potential unmet needs, where information seeking is less prevalent.

  19. Care-seeking behavior of Japanese gynecological cancer survivors suffering from adverse effects

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    Oshima Sumiko

    2013-01-01

    Full Text Available Abstract Background Post-treatment follow-up visits for gynecological cancer survivors should provide opportunities for management of adverse physical/psychological effects of therapy and early recurrence detection. However, the adequacy of such visits in Japan is poorly documented. We qualitatively explored care-seeking experiences of Japanese gynecological cancer survivors and deduced factors influencing care-seeking behaviors and treatment access. Methods We conducted 4 semi-structured focus groups comprising altogether 28 Japanese gynecological cancer survivors to collect a variety of participants’ post-treatment care-seeking behaviors through active interaction with participants. Factors influencing access to treatment for adverse effects were analyzed qualitatively. Results Survivors sought care through specialty clinic visits when regular post-treatment gynecological follow-ups were inadequate or when symptoms seemed to be non-treatment related. Information provided by hospital staff during initial treatment influenced patients’ understanding and response to adverse effects. Lack of knowledge and inaccurate symptom interpretation delayed help-seeking, exacerbating symptoms. Gynecologists’ attitudes during follow-ups frequently led survivors to cope with symptoms on their own. Information from mass media, Internet, and support groups helped patients understand symptoms and facilitated care seeking. Conclusions Post-treatment adverse effects are often untreated during follow-up visits. Awareness of possible post-treatment adverse effects is important for gynecological cancer survivors in order to obtain appropriate care if the need arises. Consultation during the follow-up visit is essential for continuity in care.

  20. Preservation of biomolecules in breast cancer tissue by a formalin-free histology system

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    Morales Azorides R

    2008-01-01

    Full Text Available Abstract Background The potential problems associated with the use of formalin in histology, such as health hazards, degradation of RNA and cross-linking of proteins are well recognized. We describe the utilization of a formalin-free fixation and processing system for tissue detection of two important biopredictors in breast cancer – estrogen receptor and HER2 – at the RNA and protein levels. Methods Parallel sections of 62 cases of breast cancer were fixed in an alcohol-based molecular fixative and in formalin. Molecular fixative samples were processed by a novel formalin-free microwave-assisted processing system that preserves DNA, RNA and proteins. Formalin-fixed samples were processed using the conventional method. Estrogen receptor was assessed by immunohistochemistry and real-time PCR. HER2 was assessed by immunohistochemistry, FISH, CISH and real-time PCR. Results The immunohistochemical reaction for estrogen receptor was similar in molecular- and formalin-fixed samples (Spearman Rank R = 0.83, p Conclusion The formalin-free tissue fixation and processing system is a practical platform for evaluation of biomolecular markers in breast cancer and it allows reliable DNA and RNA and protein studies.

  1. Patterns of information-seeking for cancer on the internet: an analysis of real world data.

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    Yishai Ofran

    Full Text Available Although traditionally the primary information sources for cancer patients have been the treating medical team, patients and their relatives increasingly turn to the Internet, though this source may be misleading and confusing. We assess Internet searching patterns to understand the information needs of cancer patients and their acquaintances, as well as to discern their underlying psychological states. We screened 232,681 anonymous users who initiated cancer-specific queries on the Yahoo Web search engine over three months, and selected for study users with high levels of interest in this topic. Searches were partitioned by expected survival for the disease being searched. We compared the search patterns of anonymous users and their contacts. Users seeking information on aggressive malignancies exhibited shorter search periods, focusing on disease- and treatment-related information. Users seeking knowledge regarding more indolent tumors searched for longer periods, alternated between different subjects, and demonstrated a high interest in topics such as support groups. Acquaintances searched for longer periods than the proband user when seeking information on aggressive (compared to indolent cancers. Information needs can be modeled as transitioning between five discrete states, each with a unique signature representing the type of information of interest to the user. Thus, early phases of information-seeking for cancer follow a specific dynamic pattern. Areas of interest are disease dependent and vary between probands and their contacts. These patterns can be used by physicians and medical Web site authors to tailor information to the needs of patients and family members.

  2. A Novel Biomolecule-Mediated Reduction of Graphene Oxide: A Multifunctional Anti-Cancer Agent.

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    Choi, Yun-Jung; Kim, Eunsu; Han, JaeWoong; Kim, Jin-Hoi; Gurunathan, Sangiliyandi

    2016-03-18

    Graphene oxide (GO) is a monolayer of carbon atoms that form a dense honeycomb structure, consisting of hydroxyl and epoxide functional groups on the two accessible sides and carboxylic groups at the edges. In contrast, graphene is a two-dimensional sheet of sp2-hybridized carbon atoms packed into a honeycomb lattice. Graphene has great potential for use in biomedical applications due to its excellent physical and chemical properties. In this study, we report a facile and environmentally friendly approach for the synthesis of reduced graphene oxide (rGO) using uric acid (UA). The synthesized uric acid-reduced graphene oxide (UA-rGO) was fully characterized by ultraviolet-visible (UV-Vis) absorption spectra, X-ray diffraction (XRD), dynamic light scattering (DLS), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and Raman spectroscopy. GO and UA-rGO induced a dose-dependent decrease in cell viability and induced cytotoxicity in human ovarian cancer cells. The results from this study suggest that UA-rGO could cause apoptosis in mammalian cells. The toxicity of UA-rGO is significantly higher than GO. Based on our findings, UA-rGO shows cytotoxic effects against human ovarian cancer cells, and its synthesis is environmentally friendly. UA-rGO significantly inhibits cell viability by increasing lactate dehydrogenase (LDH) release, reactive oxygen species (ROS) generation, activation of caspase-3, and DNA fragmentation. This is the first report to describe the comprehensive effects of UA-rGO in ovarian cancer cells. We believe that the functional aspects of newly synthesized UA-rGO will provide advances towards various biomedical applications in the near future.

  3. A Novel Biomolecule-Mediated Reduction of Graphene Oxide: A Multifunctional Anti-Cancer Agent

    Directory of Open Access Journals (Sweden)

    Yun-Jung Choi

    2016-03-01

    Full Text Available Graphene oxide (GO is a monolayer of carbon atoms that form a dense honeycomb structure, consisting of hydroxyl and epoxide functional groups on the two accessible sides and carboxylic groups at the edges. In contrast, graphene is a two-dimensional sheet of sp2-hybridized carbon atoms packed into a honeycomb lattice. Graphene has great potential for use in biomedical applications due to its excellent physical and chemical properties. In this study, we report a facile and environmentally friendly approach for the synthesis of reduced graphene oxide (rGO using uric acid (UA. The synthesized uric acid-reduced graphene oxide (UA-rGO was fully characterized by ultraviolet-visible (UV-Vis absorption spectra, X-ray diffraction (XRD, dynamic light scattering (DLS, Fourier transform infrared (FTIR, scanning electron microscopy (SEM, and Raman spectroscopy. GO and UA-rGO induced a dose-dependent decrease in cell viability and induced cytotoxicity in human ovarian cancer cells. The results from this study suggest that UA-rGO could cause apoptosis in mammalian cells. The toxicity of UA-rGO is significantly higher than GO. Based on our findings, UA-rGO shows cytotoxic effects against human ovarian cancer cells, and its synthesis is environmentally friendly. UA-rGO significantly inhibits cell viability by increasing lactate dehydrogenase (LDH release, reactive oxygen species (ROS generation, activation of caspase-3, and DNA fragmentation. This is the first report to describe the comprehensive effects of UA-rGO in ovarian cancer cells. We believe that the functional aspects of newly synthesized UA-rGO will provide advances towards various biomedical applications in the near future.

  4. Clinical characterization and risk profile of individuals seeking genetic counseling for hereditary breast cancer in Brazil.

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    Palmero, Edenir Inez; Ashton-Prolla, Patricia; da Rocha, José Cláudio C; Vargas, Fernando Regla; Kalakun, Luciane; Blom, Melissa Brauner; Azevedo, Sérgio J; Caleffi, Maira; Giugliani, Roberto; Schüler-Faccini, Lavinia

    2007-06-01

    Hereditary breast cancer (HBC) accounts for 5-10% of breast cancer cases and it significantly increases the lifetime risk of cancer. Our objective was to evaluate the sociodemographic variables, family history of cancer, breast cancer (BC) screening practices and the risk profile of cancer affected or asymptomatic at-risk women that undergo genetic counseling for hereditary breast cancer in public Brazilian cancer genetics services. Estimated lifetime risk of BC was calculated for asymptomatic women using the Gail and Claus models. The majority of women showed a moderate lifetime risk of developing BC, with an average risk of 19.7% and 19.9% by the Gail and Claus models, respectively. The average prior probability of carrying a BRCA1/2 gene mutation was 16.7% and overall only 32% fulfilled criteria for a hereditary breast cancer syndrome as assessed by family history. We conclude that a significant number of individuals at high-risk for HBC syndromes may not have access to the benefits of cancer genetic counseling in these centers. Contributing factors may include insufficient training of healthcare professionals, disinformation of cancer patients; difficult access to genetic testing and/or resistance in seeking such services. The identification and understanding of these barriers is essential to develop specific strategies to effectively achieve cancer risk reduction in this and other countries were clinical cancer genetics is not yet fully established.

  5. Ratio Based Biomarkers for the Prediction of Cancer Survival | NCI Technology Transfer Center | TTC

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    The NCI seeks licensees or co-development partners for this technology, which describes compositions, methods and kits for identifying, characterizing biomolecules expressed in a sample that are associated with the presence, the development, or progression of cancer.

  6. Does Embarrassment Contribute to Delay in Seeking Medical Care for Breast Cancer? A Review

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    Mohamadreza Neishaboury

    2015-08-01

    Full Text Available Background: Embarrassment and shame of visiting a doctor for a breast disease are among psychosocial factors that potentially contribute to delay in seeking medical advice. The purpose of this study is to review the published literature to determine if embarrassment regarding breast examination, diagnosis and treatment is associated with patient delay.Methods: We searched PubMed with the following key terms: patient acceptance of health care (MeSH, breast neoplasms/psychology (MeSH, shame (MeSH, embarrassment, delayed diagnosis, to find relevant literature published before August 2015.Results: The studies that explicitly assessed the association between embarrassment and delay for seeking medical advice for breast cancer were very limited. Among these studies, only 2 were quantitative studies, 4 were based on qualitative research and 4 were reviews. Other studies assessed attitudes in population-based surveys or included patients (females and males suffering from different types of cancer.Conclusions: Women should be educated that diseases of the breast need to be cared for as health issues in other parts of the body. They should be informed that embarrassment in this regard is not related to grace and integrity but can be potentially life-threatening. Further research is necessary to quantify the association of embarrassment or shame with delay in seeking diagnosis and treatment of breast cancer. More research can elucidate the ways that the negative impact of shame/embarrassment can be minimized in different ethnic groups.

  7. Predicting Cancer Information Seeking Behaviors of Smokers, Former Smokers and Nonsmokers Using the 2012 Health Information National Trends Survey

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    Lee, Suekyung

    2013-01-01

    Cancer can be one of the most serious diseases that can result in a costly reduction in the quality of life. Among a number of cancer risk factors, tobacco use has been identified as the leading preventable cause of deaths. Prior research has suggested that cancer information seeking may be a pre-step to adopt health protective behaviors that can…

  8. Barriers to Seeking Help for Skin Cancer Detection in Rural Australia

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    Fennell, Kate M.; Martin, Kimberley; Wilson, Carlene J.; Trenerry, Camilla; Sharplin, Greg; Dollman, James

    2017-01-01

    This study explores rural South Australians’ barriers to help-seeking for skin cancer detection. A total of 201 randomly selected rural adults (18–94 years, 66% female) were presented with a skin-cancer-related scenario via telephone and were asked the extent to which various barriers would impede their help-seeking, based on an amended version of the Barriers to Help-Seeking Scale. Older (≥63 years) and less educated participants endorsed barriers more strongly than their younger, more educated counterparts in the following domains; “Concrete barriers and distrust of caregivers”, “Emotional control”, “Minimising problem and Normalisation”, “Need for control and self-reliance” (every domain other than “Privacy”). Socioeconomic disadvantage, gender, and farmer status did not predict stronger overall barriers, but some gender and occupation-related differences were detected at the item level. Farmers were also more likely to endorse the “Minimising problem and normalization” domain than their non-farmer working rural counterparts. Widely endorsed barriers included the tendency to minimise the problem, a desire to remain in control/not be influenced by others, reluctance to show emotion or complain, and having concerns about privacy or waiting times. PMID:28208803

  9. Internet access and online cancer information seeking among Latino immigrants from safety net clinics.

    Science.gov (United States)

    Selsky, Claire; Luta, George; Noone, Anne-Michelle; Huerta, Elmer E; Mandelblatt, Jeanne S

    2013-01-01

    Internet use is widespread, but little is known about Internet use for cancer information among Latinos, especially those who rely on safety net clinics. The authors investigated access to and intended use of the Internet for cancer information among low income, immigrant Latinos predominately from Central and South America. A cross-sectional study of 1,273 Latinos 21 years and older attending safety net clinics or health fairs was conducted from June 2007 to November 2008. The authors used logistic regression models to evaluate associations of age, acculturation, psychosocial factors and other covariates with Internet access and intended use of the Internet for cancer information among those with access. Of the sample, 44% reported Internet access. Higher information self-efficacy and greater trust in the Internet were independently associated with Internet access (p = .05 and p cancer help online if they needed information. Those with younger age and higher acculturation, education and self-efficacy had higher odds of intended Internet use for cancer information, considering covariates. In addition, those with high (vs. low) perceived risk of cancer (OR = 1.76; 95% CI [1.14, 2.73]; p = .01) and higher levels of trust in online health information (OR = 1.47 per one-point increase; 95% [CI 1.19, 1.82]; p = .0004) were more likely to intend to seek cancer information online. These findings that Internet access is fairly high in the immigrant Latino population and that the Internet is a trusted source of cancer information suggest that the Internet may be a channel for cancer control interventions.

  10. Method for detecting biomolecules

    Science.gov (United States)

    Huo, Qisheng; Liu, Jun

    2008-08-12

    A method for detecting and measuring the concentration of biomolecules in solution, utilizing a conducting electrode in contact with a solution containing target biomolecules, with a film with controllable pore size distribution characteristics applied to at least one surface of the conducting electrode. The film is functionalized with probe molecules that chemically interact with the target biomolecules at the film surface, blocking indicator molecules present in solution from diffusing from the solution to the electrode, thereby changing the electrochemical response of the electrode

  11. Navigating the cancer information environment: The reciprocal relationship between patient-clinician information engagement and information seeking from nonmedical sources.

    Science.gov (United States)

    Moldovan-Johnson, Mihaela; Tan, Andy S L; Hornik, Robert C

    2014-01-01

    Prior theory has argued and empirical studies have shown that cancer patients rely on information from their health care providers as well as lay sources to understand and make decisions about their disease. However, research on the dynamic and interdependent nature of cancer patients' engagement with different information sources is lacking. This study tested the hypotheses that patient-clinician information engagement and information seeking from nonmedical sources influence one another longitudinally among a representative cohort of 1,293 cancer survivors in Pennsylvania. The study hypotheses were supported in a series of lagged multiple regression analyses. Baseline seeking information from nonmedical sources positively predicted subsequent patient-clinician information engagement at 1-year follow-up. The reverse relationship was also statistically significant; baseline patient-clinician information engagement positively predicted information seeking from nonmedical sources at follow-up. These findings suggest that cancer survivors move between nonmedical and clinician sources in a dynamic way to learn about their disease.

  12. Associations of self-rated health and socioeconomic status with information seeking and avoiding behavior among post- treatment cancer patients.

    Science.gov (United States)

    Jung, Minsoo

    2014-01-01

    This study investigated how self-rated health and socioeconomic status are associated with behaviour of cancer survivors regarding desire for information. For this association, we compared survivors who did not seek information about cancer with those who did. We examined how sociodemographic, socioeconomic, cancer- related, and health information factors are associated with self-rated health (SRH) by health information seeking/ avoiding behavior in a survey of 502 post-treatment cancer patients. In the information seeking group, all four factors exhibited significant relationships with SRH. SRH values were significantly high for women (pinformation by themselves (pinformation avoiding group, not only were there no significant relationships between socioeconomic status (SES) and SRH, but there were negative associations between their attitude/capacity and the SRH. In terms of communication equity, the promotion of information seeking behavior can be an effective way to reduce health disparities that are caused by social inequalities. Information avoiding behavior, however, does not exhibit a negative contribution toward the relationship between SRH and SES. Information seeking behavior was positively associated with SRH, but avoiding behavior was not negatively associated. We thus need to eliminate communication inequalities using health intervention to support information seeking behavior, while simultaneously providing support for avoiders.

  13. Differences in Cancer Information Seeking Behavior, Preferences, and Awareness Between Cancer Survivors and Healthy Controls: A National, Population-Based Survey

    Science.gov (United States)

    Roach, Abbey R.; Lykins, Emily L.B.; Gochett, Celestine G.; Brechting, Emily H.; Graue, Lili O.; Andrykowski, Michael A.

    2012-01-01

    Background No research has examined how cancer diagnosis and treatment might alter information source preferences or opinions. Methods Data from 719 cancer survivors (CS group) and 2012 matched healthy controls (NCC group) regarding cancer-related information seeking behavior, preferences, and awareness from the population-based 2003 Health Information National Trends Survey (HINTS) was examined. Results The CS group reported greater consumption of cancer-related information but the CS and NCC groups did not differ in information source use or preferences. The CS group was more confident of their ability to get cancer information, reported more trust in health care professionals and television as cancer information sources, but evaluated their recent cancer information seeking experiences more negatively than the NCC group. Awareness of cancer information resources was surprisingly low in both the CS and NCC groups. Conclusions Cancer diagnosis and treatment subtly alters cancer information seeking preferences and experience. However awareness and use of cancer information resources was relatively low regardless of personal history of cancer. PMID:19259869

  14. Reaching rural women: breast cancer prevention information seeking behaviors and interest in Internet, cell phone, and text use.

    Science.gov (United States)

    Kratzke, Cynthia; Wilson, Susan; Vilchis, Hugo

    2013-02-01

    The purpose of this study was to examine the breast cancer prevention information seeking behaviors among rural women, the prevalence of Internet, cell, and text use, and interest to receive breast cancer prevention information cell and text messages. While growing literature for breast cancer information sources supports the use of the Internet, little is known about breast cancer prevention information seeking behaviors among rural women and mobile technology. Using a cross-sectional study design, data were collected using a survey. McGuire's Input-Ouput Model was used as the framework. Self-reported data were obtained from a convenience sample of 157 women with a mean age of 60 (SD = 12.12) at a rural New Mexico imaging center. Common interpersonal information sources were doctors, nurses, and friends and common channel information sources were television, magazines, and Internet. Overall, 87% used cell phones, 20% had an interest to receive cell phone breast cancer prevention messages, 47% used text messaging, 36% had an interest to receive text breast cancer prevention messages, and 37% had an interest to receive mammogram reminder text messages. Bivariate analysis revealed significant differences between age, income, and race/ethnicity and use of cell phones or text messaging. There were no differences between age and receiving text messages or text mammogram reminders. Assessment of health information seeking behaviors is important for community health educators to target populations for program development. Future research may identify additional socio-cultural differences.

  15. Fatalistic Cancer Beliefs and Information Seeking in Formerly Incarcerated African-American and Hispanic Men: Implications for Cancer Health Communication and Research.

    Science.gov (United States)

    Valera, Pamela; Lian, Zi; Brotzman, Laura; Reid, Andrea

    2017-03-03

    African-American and Hispanic men are disproportionately affected by cancer experiencing higher rates of cancer-related morbidity and mortality for many cancers (but not all). These challenges may be magnified for a subpopulation of African-American and Hispanic men who have been incarcerated. A survey assessing demographics, incarceration experience, psychosocial, behavioral, and cancer health information seeking was administered to 230 previously incarcerated men aged 35 years and older. Data analysis was performed to assess the association between fatalism, perceived susceptibility, and health information seeking in this population. This study revealed the following: the majority of the participants (68.7%) held the fatalistic belief: "When I think of cancer, I automatically think of death." Second, the fatalistic belief, "There's not much you can do to lower your chances of getting cancer," is more prevalent among those who perceived a higher risk of developing cancer. Third, older participants (those between 55 and 70 years old) and widowed are less likely to think of death when they think of cancer. In addition, those who use the Internet to look for health or medical information (i.e., engaging in health information seeking) are less likely to agree with the fatalistic belief: "It seems like everything causes cancer." Given the high incidence of certain cancers among African-American and Hispanic men and the vulnerability of those involved in the criminal justice system, our findings highlight the importance of understanding perceived susceptibility to cancer, fatalistic beliefs about cancer, and information seeking in formerly incarcerated men.

  16. Biomolecules in Astrobiology

    OpenAIRE

    Meringer, Markus

    2013-01-01

    Astrobiology is the study of the origin, distribution and future of life in the universe, biomolecules are molecules produced by living organisms. This talk reviews known facts and open questions about biomolecules in the context of Astrobiology and introduces a research project on "Creating a Reference Set of Amino Acids Structures for Use in Multiple Astrobiology Investigations" that tries to find answers using computational methods.

  17. Assessing Technologies for Information-Seeking on Prostate Cancer Screening by Low-Income Men

    Directory of Open Access Journals (Sweden)

    Susan W. McRoy

    2014-11-01

    Full Text Available Purpose: This paper presents a multipart investigation of the benefits and challenges in deploying automated question-answering as an alternative to web-based searching to provide information about prostate cancer screening for low-income men age 40 years and older. Methods: The study comprised: 1 a survey assessing current use of the Internet, mobile phones and texting; 2 a controlled observational study of both web-based searching and automated question-answering for information about prostate cancer; and 3 a formative field study in which subjects interacted with a health department nurse using text messages. Results: Survey results suggest the target population has greater access to, and familiarity with, cell phones and text messaging compared to the Internet and web-based searching. Participants were significantly more confident using a cell phone and preferred to get health information through text messaging. Participants in the controlled observational study accepted the text messaging system, with most indicating it answered their questions, was easy to use and was a favorable tool for information-seeking. The field study also demonstrated potential for automated question-answering and text messaging to help the target population access health information. Conclusions: A two-way text messaging system has great potential to promote health communication and health information distribution. Participant interest in this system was high and did not seem to be specific to prostate cancer screening, suggesting that information about other topics, such as high blood pressure screening, could be provided similarly. We believe more investigations should be focused on this area, especially on benefits for the low-income community.

  18. Increasing awareness of gynecological cancer symptoms and reducing barriers to medical help seeking: does health literacy play a role?

    Science.gov (United States)

    Boxell, Emily M; Smith, Samuel G; Morris, Melanie; Kummer, Sonja; Rowlands, Gill; Waller, Jo; Wardle, Jane; Simon, Alice E

    2012-01-01

    Health literacy may influence the efficacy of print-based public health interventions. A key part of the U.K. cancer control strategy is to provide information to the public on earlier diagnoses with a view to improving the United Kingdom's relatively poor 1-year cancer survival statistics. This study examined the effect of health literacy on the efficacy of a gynecological cancer information leaflet. Participants (n = 451) were recruited from 17 Cancer Research UK events. Health literacy was assessed with the Newest Vital Sign test. Gynecological cancer symptom awareness and barriers to medical help seeking were assessed before and after participants read the leaflet. Symptom awareness improved, and barriers to medical help seeking were reduced (ps .05). As predicted, individuals with lower health literacy benefited less after exposure to the leaflet (ps information design principles in the development of the leaflet, more intensive efforts may be required to ensure that inequalities are not exacerbated by reliance on print-based public health interventions.

  19. Frustration in biomolecules.

    Science.gov (United States)

    Ferreiro, Diego U; Komives, Elizabeth A; Wolynes, Peter G

    2014-11-01

    Biomolecules are the prime information processing elements of living matter. Most of these inanimate systems are polymers that compute their own structures and dynamics using as input seemingly random character strings of their sequence, following which they coalesce and perform integrated cellular functions. In large computational systems with finite interaction-codes, the appearance of conflicting goals is inevitable. Simple conflicting forces can lead to quite complex structures and behaviors, leading to the concept of frustration in condensed matter. We present here some basic ideas about frustration in biomolecules and how the frustration concept leads to a better appreciation of many aspects of the architecture of biomolecules, and especially how biomolecular structure connects to function by means of localized frustration. These ideas are simultaneously both seductively simple and perilously subtle to grasp completely. The energy landscape theory of protein folding provides a framework for quantifying frustration in large systems and has been implemented at many levels of description. We first review the notion of frustration from the areas of abstract logic and its uses in simple condensed matter systems. We discuss then how the frustration concept applies specifically to heteropolymers, testing folding landscape theory in computer simulations of protein models and in experimentally accessible systems. Studying the aspects of frustration averaged over many proteins provides ways to infer energy functions useful for reliable structure prediction. We discuss how frustration affects folding mechanisms. We review here how the biological functions of proteins are related to subtle local physical frustration effects and how frustration influences the appearance of metastable states, the nature of binding processes, catalysis and allosteric transitions. In this review, we also emphasize that frustration, far from being always a bad thing, is an essential feature

  20. Biomolecule-functionalized polymer brushes.

    Science.gov (United States)

    Jiang, Hui; Xu, Fu-Jian

    2013-04-21

    Functional polymer brushes have been utilized extensively for the immobilization of biomolecules, which is of crucial importance for the development of biosensors and biotechnology. Recent progress in polymerization methods, in particular surface-initiated atom transfer radical polymerization (ATRP), has provided a unique means for the design and synthesis of new biomolecule-functionalized polymer brushes. This current review summarizes such recent research activities. The different preparation strategies for biomolecule immobilization through polymer brush spacers are described in detail. The functional groups of the polymer brushes used for biomolecule immobilization include epoxide, carboxylic acid, hydroxyl, aldehyde, and amine groups. The recent research activities indicate that functional polymer brushes become versatile and powerful spacers for immobilization of various biomolecules to maximize their functionalities. This review also demonstrates that surface-initiated ATRP is used more frequently than other polymerization methods in the designs of new biomolecule-functionalized polymer brushes.

  1. Overview of the use of theory to understand infrared and Raman spectra and images of biomolecules: colorectal cancer as an example

    DEFF Research Database (Denmark)

    Piva, J. A. A. C.; Silva, J. L. R.; Raniero, L.

    2011-01-01

    In this work, we present the state of the art in the use of theory (first principles, molecular dynamics, and statistical methods) for interpreting and understanding the infrared (vibrational) absorption and Raman scattering spectra. It is discussed how they can be used in combination with purely...... experimental studies to generate infrared and Raman images of biomolecules in biologically relevant solutions, including fluids, cells, and both healthy and diseased tissue. The species and conformers of the individual biomolecules are in many cases not stable structures, species, or conformers in the isolated...... and that the models used must take this into account. Hence, the use of statistical methods to interpret and understand the infrared and Raman spectra and images from biological tissues, cells, parts of cells, fluids, and even whole organism should change accordingly. As the species, conformers and structures...

  2. Motives of cancer patients for using the Internet to seek social support.

    Science.gov (United States)

    Yli-Uotila, T; Rantanen, A; Suominen, T

    2013-03-01

    The purpose of the study was to describe why Finnish cancer patients choose the internet as a source of social support. The data were collected in May 2010, using an online questionnaire with open-ended questions, through four discussion forums on the websites of the non-profit Cancer Society of Finland. Seventy-four adult patients with cancer participated. The data were analysed using inductive content analysis. The mean age of the participants was 53 years and they were predominantly women. The most common cancer was breast cancer and more than three quarters of the participants had suffered from cancer for less than 5 years. The initial stimuli to use the internet as a source of social support were the ease of communication and access to information as well as the need for emotional and informational support. The actual motives that drove the use of the internet as a source of social support were the requirements for information and peer support, internet technology, a lack of support outside the internet and the negative experiences caused by the illness. The fact that there is an enormous need for information as well as for emotional support and that cancer treatment in Finland is concentrated in major hospitals, to which cancer patients may travel a considerable distance, suggests that nurses should learn to make more frequent virtual contact with their patients.

  3. Quality of life and mental health among women with ovarian cancer: examining the role of emotional and instrumental social support seeking.

    Science.gov (United States)

    Hill, Erin M

    2016-07-01

    The purpose of the present study was to examine the role of emotional and instrumental social support seeking in the quality of life (QOL) and mental health of women with ovarian cancer. Participants were recruited through the Pennsylvania Cancer Registry, and one hundred women took part in a mail questionnaire that collected information on their demographics, medical status, social support seeking, QOL and mental health including anxiety, depression and stress. Hierarchical linear regression analyses were conducted to assess the influence of emotional and instrumental social support seeking on QOL and mental health. After controlling for remission status, greater emotional social support seeking was predictive of higher overall QOL, social/family QOL, functional QOL and lower depression scores. Instrumental social support seeking was not significant in the models. The results illustrate that social support seeking as a coping mechanism is an important consideration in the QOL and mental health of women with ovarian cancer. Future studies should examine the psychological and behavioral mediators of the relationship to further understand the QOL and mental health of women with ovarian cancer.

  4. Health seeking behavioral analysis associated with breast cancer screening among Asian American women

    Directory of Open Access Journals (Sweden)

    Ma GX

    2012-05-01

    Full Text Available Grace X Ma,1 Wanzhen Gao,1 Sunmin Lee,2 MinQi Wang,3 Yin Tan,1 Steven E Shive,1,41Department of Public Health, Center for Asian Health, College of Health Professions, Temple University, Philadelphia, PA, USA; 2Department of Epidemiology and Biostatistics, School of Public Health, University of Maryland, College Park, MD, USA; 3Department of Public and Community Health, University of Maryland, College Park, Maryland, MD, USA; 4East Stroudsburg University, East Stroudsburg, PA, USAObjective: The purpose of this community-based study was to apply a Sociocultural Health Behavior Model to determine the association of factors proposed in the model with breast cancer screening behaviors among Asian American women.Methods: A cross-sectional design included a sample of 682 Chinese, Korean, and Vietnamese women aged 40 years and older. The frequency distribution analysis and Chi-square analysis were used for the initial screening of the following variables: sociodemographic, cultural, enabling, environmental, and social support. Univariate and multivariate analyses were conducted on factors for breast cancer screening using multinomial logistic regression analysis.Results: Correlates to positive breast cancer screening included demographics (ethnicity, cultural factors (living in the United States for 15 years or more, speaking English well, enabling factors (having a regular physician to visit, health insurance covering the screening, and family/social support factors (those who had a family/friend receiving a mammogram.Conclusions: The results of this study suggest that breast cancer screening programs will be more effective if they include the cultural and health beliefs, enabling, and social support factors associated with breast cancer screening. The use of community organizations may play a role in helping to increase breast cancer screening rates among Asian American women.Keywords: breast cancer screening, Vietnamese, Korean, Chinese, breast

  5. Seeking out the sweet spot in cancer therapeutics: an interview with Lewis Cantley

    Science.gov (United States)

    2016-01-01

    Lewis C. Cantley, Director of the Sandra and Edward Meyer Cancer Center at Weill Cornell Medicine, is a world leader in cancer and metabolic disease research. His seminal discoveries have shed light on the regulation of ion pumps and other transport proteins, insulin-mediated regulation of glucose metabolism and the role of signal transduction networks in cell transformation. At Tufts University in the 1980s, Lewis and his collaborators unveiled and characterized the phosphoinositide 3-kinase (PI3K) signaling pathway; a discovery that revolutionized the field of lipid signaling. In this interview, he documents his journey from serendipitous discovery of the pathway to determining its diverse physiological functions and role in cancer – an incredible odyssey that has laid the groundwork for clinical trials based on PI3K inhibitors. He also discusses the impact his early life had in spurring a thirst to understand biological processes at the molecular level, highlights how his multiple collaborations have helped in translating his basic discoveries to the clinic and explains why eating a high-sugar diet can be harmful. Ongoing studies in the Cantley lab are aimed at determining the mechanistic underpinnings of pancreatic, colorectal, ovarian and breast cancers, particularly the role of cellular metabolic pathways. The group has recently shown, amongst other breakthroughs, that vitamin C could provide a promising therapy for certain hard-to-treat cancers. PMID:27491070

  6. Differences among college women for breast cancer prevention acquired information-seeking, desired apps and texts, and daughter-initiated information to mothers.

    Science.gov (United States)

    Kratzke, Cynthia; Amatya, Anup; Vilchis, Hugo

    2014-04-01

    The purpose of this study was to examine among college women acquired breast cancer prevention information-seeking, desired apps and texts, and information given to mothers. Using a cross-sectional study, a survey was administered to college women at a southwestern university. College women (n = 546) used the Internet (44 %) for active breast cancer prevention information-seeking and used the Internet (74 %), magazines (69 %), and television (59 %) for passive information receipt. Over half of the participants desired breast cancer prevention apps (54 %) and texts (51 %). Logistic regression analyses revealed predictors for interest to receive apps were ethnicity (Hispanic), lower self-efficacy, actively seeking online information, and older age and predictors for interest to receive texts were lower self-efficacy and higher university level. Eighteen percent of college women (n = 99) reported giving information to mothers and reported in an open-ended item the types of information given to mothers. Predictors for giving information to mothers were actively and passively seeking online information, breast self-exam practice, and higher university level. Screenings were the most frequent types of information given to mothers. Breast cancer prevention information using apps, texts, or Internet and daughter-initiated information for mothers should be considered in health promotion targeting college students or young women in communities. Future research is needed to examine the quality of apps, texts, and online information and cultural differences for breast cancer prevention sources.

  7. Time from first symptom experience to help seeking for colorectal cancer patients

    DEFF Research Database (Denmark)

    Jensen, Line Flytkjær; Hvidberg, Line; Pedersen, Anette Fischer;

    2016-01-01

    anvendte vi Leventhals Common Sense Model til at undersøge forskellige aspekter af patienters symptomrepræsentationer, deres oplevede symptomer samt deres tidsintervaller op til diagnose. Vi indhentede data om sociodemografi fra Danmarks Statistik. Studiet viste, at det mediane patientinterval for hele...... score på timeline cyclical (fx personer der oplevede, at deres symptomer kom og gik) var mere tilbøjelig til at have langt patient interval. Studiet bidrager med ny viden om, hvordan patienter med kolorektal cancer tænker om deres symptomer før lægesøgning, og hvordan dette påvirker deres...

  8. A source for microhydrated biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Förstel, M.; Hergenhahn, U., E-mail: uwe.hergenhahn@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, Wendelsteinstraße 1, 17491 Greifswald (Germany); Neustetter, M.; Denifl, S. [Institut für Ionenphysik und Angewandte Physik, Technikerstraße 25, 6020 Innsbruck (Austria); Lelievre, F. [Max-Planck-Institut für Plasmaphysik, Wendelsteinstraße 1, 17491 Greifswald (Germany); University Paris-Sud 11, Faculté des Science d’Orsay, 91405 Orsay (France)

    2015-07-15

    We describe the construction of an apparatus for the production of a molecular jet of microhydrated biomolecules. Our design uses a water reservoir producing water vapour, which then passes through a separate reservoir containing a vapour of a sublimated biomolecule. The mixture coexpands into a molecular beam apparatus through a conical nozzle. Mass spectra showing water-adenin and water-uracil complexes are shown as typical examples. Suitable expansion conditions are reached without the use of an inert carrier gas.

  9. Seeking genetic susceptibility variants for colorectal cancer: the EPICOLON consortium experience.

    Science.gov (United States)

    Castellví-Bel, Sergi; Ruiz-Ponte, Clara; Fernández-Rozadilla, Ceres; Abulí, Anna; Muñoz, Jenifer; Bessa, Xavier; Brea-Fernández, Alejandro; Ferro, Marta; Giráldez, María Dolores; Xicola, Rosa M; Llor, Xavier; Jover, Rodrigo; Piqué, Josep M; Andreu, Montserrat; Castells, Antoni; Carracedo, Angel

    2012-03-01

    The EPICOLON consortium was initiated in 1999 by the Gastrointestinal Oncology Group of the Spanish Gastroenterology Association. It recruited consecutive, unselected, population-based colorectal cancer (CRC) cases and control subjects matched by age and gender without personal or familial history of cancer all over Spain with the main goal of gaining knowledge in Lynch syndrome and familial CRC. This epidemiological, prospective and multicentre study collected extensive clinical data and biological samples from ∼2000 CRC cases and 2000 controls in Phases 1 and 2 involving 25 and 14 participating hospitals, respectively. Genetic susceptibility projects in EPICOLON have included candidate-gene approaches evaluating single-nucleotide polymorphisms/genes from the historical category (linked to CRC risk by previous studies), from human syntenic CRC susceptibility regions identified in mouse, from the CRC carcinogenesis-related pathways Wnt and BMP, from regions 9q22 and 3q22 with positive linkage in CRC families, and from the mucin gene family. This consortium has also participated actively in the identification 5 of the 16 common, low-penetrance CRC genetic variants identified so far by genome-wide association studies. Finishing their own pangenomic study and performing whole-exome sequencing in selected CRC samples are among EPICOLON future research prospects.

  10. RADIONUCLIDE STUDIES USING TUMOR-SEEKING RADIOPHARMACEUTICALS IN THE DIAGNOSIS OF PROSTATE CANCER

    Directory of Open Access Journals (Sweden)

    N. I. Tarassov

    2009-01-01

    Full Text Available Object: to evaluate the efficiency of prostate scintigraphy in the prebioptic diagnosis of prostate cancer (PC.Subjects and methods. Two hundred and two patients with suspected PC underwent comprehensive examination, including 99mTc-technetril prostate scintigraphy and a morphometric study of biopsy material columns. A computer program (official registration certificate No. 2007614475 dated October 24, 2007 was worked out and patented to calculate the intensity of accumulation of radiopharmaceuticals in different portions of the right and left prostate lobes.Results and discussion. When the division index point «pathological focus/background», 1.5; ≤ 1.5, healthy; > 1.5 suspected prostate cancer was used, the sensitivity of prostate scintigraphy was 81.65%; its specificity was 87.1%; the diagnostic effectiveness was 84.37%.Conclusion: The application of prostate scintigraphy can improve indicators for early detection of PC, due to the purposeful detection of the points, enhance the effectiveness of biopsy, and, having more grounds than the early ones, to exclude this disease at the prebioptic stage. The method is noninvasive and can be used to monitor patients with suspected PC.

  11. RADIONUCLIDE STUDIES USING TUMOR-SEEKING RADIOPHARMACEUTICALS IN THE DIAGNOSIS OF PROSTATE CANCER

    Directory of Open Access Journals (Sweden)

    N. I. Tarassov

    2014-08-01

    Full Text Available Object: to evaluate the efficiency of prostate scintigraphy in the prebioptic diagnosis of prostate cancer (PC.Subjects and methods. Two hundred and two patients with suspected PC underwent comprehensive examination, including 99mTc-technetril prostate scintigraphy and a morphometric study of biopsy material columns. A computer program (official registration certificate No. 2007614475 dated October 24, 2007 was worked out and patented to calculate the intensity of accumulation of radiopharmaceuticals in different portions of the right and left prostate lobes.Results and discussion. When the division index point «pathological focus/background», 1.5; ≤ 1.5, healthy; > 1.5 suspected prostate cancer was used, the sensitivity of prostate scintigraphy was 81.65%; its specificity was 87.1%; the diagnostic effectiveness was 84.37%.Conclusion: The application of prostate scintigraphy can improve indicators for early detection of PC, due to the purposeful detection of the points, enhance the effectiveness of biopsy, and, having more grounds than the early ones, to exclude this disease at the prebioptic stage. The method is noninvasive and can be used to monitor patients with suspected PC.

  12. Knowledge, Attitude and Health Seeking Behavior of Health Care Professionals regarding Breast and Cervical Cancer at Indian Medical College

    Directory of Open Access Journals (Sweden)

    Rajal Thaker*

    2015-01-01

    Full Text Available Research article Knowledge, Attitude and Health Seeking Behavior of Health Care Professionals regarding Breast and Cervical Cancer at Indian Medical College Rajal Thaker*,Kay Perrin**, Ellen Daley *** ,Cheryl Vamos ****,Pankaj Patel ***** * Associate Professor Obstetrics and Gynaecology, ***** Dean; Smt N H L Municipal Medical College, Ahmedabad 380 006, India. ** Associate Professor, *** Associate Professor, Co-Director, Center for Transdisciplinary Research in Women’s Health (CTR-WH, **** Research Assistant Professor, Associate Director; Center for Transdisciplinary Research in Women’s Health (CTR-WH; University of South Florida College of Public Health, USA Abstract Background: Women’s preventative health is a major public health issue across the globe. From prenatal care to post-menopausal screenings, women’s preventative care covers a wide spectrum of issues and topics. There is limited data on knowledge and practices of screening methods of breast and cervical cancers among female health care professionals in India. This study examines health care professionals’ knowledge and practices regarding breast and cervical cancer screenings in India. Material and Methods After clearance from Institutional Review Board (IRB of University of South Florida (USF and permission from Smt N H L Municipal Medical College (NHLMMC, a cross- sectional interview based survey was conducted amongst female teaching faculty and female consultants of NHLMMC, two affiliated teaching hospitals (Sheth V S General Hospital and Smt S C L General Hospital, and SBB college of Physiotherapy during the year 2010-2011. Conclusion Findings highlight the critical need for education and practice with regards to women’s preventive health care. Practice of Breast Self Examination (BSE and Pap test amongst the health care professionals was quite low; however, those who were 40 year or older were more conscious about their health. Findings also highlight the need for

  13. The Effects of Experienced Uncertainty and Patients' Assessments of Cancer-Related Information-Seeking Experiences on Fatalistic Beliefs and Trust in Physicians.

    Science.gov (United States)

    Hong, Soo Jung; You, Kyung Han

    2016-12-01

    Using the 2013 HINTS 4 Cycle 2 data representing a general population sample, this study investigates the effects of patients' experiences of uncertainty about prostate cancer during doctor-patient communication, as well as patients' positive assessments of their cancer-related information-seeking experiences, on their fatalistic beliefs regarding cancer and their trust in physicians. Our tests show significant differences in trust in physicians among men who do and do not experience uncertainty about the prostate-specific antigen (PSA) test during doctor-patient communication. The analysis also indicates that individuals with experiences of uncertainty about the PSA test are more likely than those without such experiences of uncertainty to place their trust in doctors. However, no apparent difference or association exists when there are uncertainties relating to treatment choices regarding slow-growing cancer or treatment side effects. Nevertheless, as hypothesized, individuals who positively evaluate their cancer-related information-seeking experiences are less likely to have fatalistic beliefs about cancer. Furthermore, patients' positive assessments are highly predictive of their levels of trust in their physicians. Additionally, tests of interaction effects show that individuals' levels of education moderate the association between uncertainty experiences about the PSA test and both cancer fatalism and trust in physicians. Further implications and limitations of the study are discussed.

  14. The role of patient-clinician information engagement and information seeking from nonmedical channels in fruit and vegetable intake among cancer patients.

    Science.gov (United States)

    Moldovan-Johnson, Mihaela; Martinez, Lourdes; Lewis, Nehama; Freres, Derek; Hornik, Robert C

    2014-12-01

    Previous research suggests positive effects of health information seeking on prevention behaviors such as diet, exercise, and fruit and vegetable consumption. The present study builds upon this research and strengthens causal claims from it by examining the lagged effect of patient-clinician information engagement on fruit and vegetable consumption as well as the indirect effect on the outcome through seeking information from nonmedical channels. The results are based on data collected from a randomly drawn sample of breast, prostate, and colorectal cancer patients from the Pennsylvania Cancer Registry who completed mail surveys in the Fall of 2006 and 2007. There was a 65% response rate for baseline subjects (resulting n = 2,013); of those, 1,293 were interviewed 1 year later, and 1,257 were available for our analyses. Results show a positive lagged main effect of patient-clinician information engagement at baseline on fruit and vegetable consumption at follow-up (B = 0.26, SE = 0.10, p = .01). The mediation analysis shows that patient-clinician information engagement leads to increased fruit and vegetable consumption among cancer patients, in part through patients' information seeking from nonmedical channels. Implications of these findings for the cancer patient population and for physicians are discussed.

  15. Green engineered biomolecule-capped silver and copper nanohybrids using Prosopis cineraria leaf extract: Enhanced antibacterial activity against microbial pathogens of public health relevance and cytotoxicity on human breast cancer cells (MCF-7).

    Science.gov (United States)

    Jinu, U; Gomathi, M; Saiqa, I; Geetha, N; Benelli, G; Venkatachalam, P

    2017-02-16

    This research focused on green engineering and characterization of silver (PcAgNPs) and copper nanoparticles (PcCuNPs) using Prosopis cineraria (Pc) leaf extract prepared by using microwave irradiation. We studied their enhanced antimicrobial activity on human pathogens as well as cytotoxicity on breast cancer cells (MCF-7). Biofabricated silver and copper nanoparticles exhibited UV-Visible absorbance peaks at 420 nm and 575 nm, confirming the bioreduction and stabilization of nanoparticles. Nanoparticles were characterized by FTIR, XRD, FESEM, and EDX analysis. FTIR results indicated the presence of alcohols, alkanes, aromatics, phenols, ethers, benzene, amines and amides that were possibly involved in the reduction and capping of silver and copper ions. XRD analysis was performed to confirm the crystalline nature of the silver and copper nanoparticles. FESEM analysis suggested that the nanoparticles were hexagonal or spherical in shape with size ranging from 20 to 44.49 nm and 18.9-32.09 nm for AgNPs and CuNPs, respectively. EDX analysis confirmed the presence of silver and copper elemental signals in the nanoparticles. The bioengineered silver and copper nanohybrids showed enhanced antimicrobial activity against Gram-positive and Gram-negative MDR human pathogens. MTT assay results indicated that CuNPs show potential cytotoxic effect followed by AgNPs against MCF-7 cancer cell line. IC50 were 65.27 μg/ml, 37.02 μg/ml and 197.3 μg/ml for PcAgNPs, PcCuNPs and P. cineraria leaf extracts, respectively, treated MCF-7 cells. The present investigation highlighted an effective protocol for microwave-assisted synthesis of biomolecule-loaded silver and copper nanoparticles with enhanced antibacterial and anticancer activity. Results strongly suggested that bioengineered AgNPs and CuNPs could be used as potential tools against microbial pathogens and cancer cells.

  16. Induced apoptosis in melanocytes cancer cell and oxidation in biomolecules through deuterium oxide generated from atmospheric pressure non-thermal plasma jet

    Science.gov (United States)

    Kumar, Naresh; Attri, Pankaj; Yadav, Dharmendra Kumar; Choi, Jinsung; Choi, Eun Ha; Uhm, Han Sup

    2014-12-01

    Recently, atmospheric-pressure non-thermal plasma-jets (APPJ) are being for the cancer treatment. However, APPJ still has drawbacks such as efficiency and rise in temperature after treatment. So, in this work, a synergetic agent D2O vapour is attached to APPJ which not only increase the efficiency of plasma source against cancer treatment, but also controlled the temperature during the treatment. OD generated by the combination of D2O + N2 plasma helped in enhancing the efficiency of APPJ. We observed OD induced apoptosis on melanocytes G361 cancer cells through DNA damage signalling cascade. Additionally, we observed that plasma induces ROS, which activated MAPK p38 and inhibits p42/p44 MAPK, leading to cancer cell death. We have also studied DNA oxidation by extracting DNA from treated cancer cell and then analysed the effects of OD/OH/D2O2/H2O2 on protein modification and oxidation. Additionally, we attempted molecular docking approaches to check the action of D2O2 on the apoptosis related genes. Further, we confirmed the formation of OD/OH simultaneously in the solution using optical emission spectroscopy. Moreover, the simultaneous generation of D2O2/H2O2 was detected by the use of confocal Raman spectroscopy and density measurements.

  17. Induced apoptosis in melanocytes cancer cell and oxidation in biomolecules through deuterium oxide generated from atmospheric pressure non-thermal plasma jet.

    Science.gov (United States)

    Kumar, Naresh; Attri, Pankaj; Yadav, Dharmendra Kumar; Choi, Jinsung; Choi, Eun Ha; Uhm, Han Sup

    2014-12-23

    Recently, atmospheric-pressure non-thermal plasma-jets (APPJ) are being for the cancer treatment. However, APPJ still has drawbacks such as efficiency and rise in temperature after treatment. So, in this work, a synergetic agent D2O vapour is attached to APPJ which not only increase the efficiency of plasma source against cancer treatment, but also controlled the temperature during the treatment. OD generated by the combination of D2O + N2 plasma helped in enhancing the efficiency of APPJ. We observed OD induced apoptosis on melanocytes G361 cancer cells through DNA damage signalling cascade. Additionally, we observed that plasma induces ROS, which activated MAPK p38 and inhibits p42/p44 MAPK, leading to cancer cell death. We have also studied DNA oxidation by extracting DNA from treated cancer cell and then analysed the effects of OD/OH/D2O2/H2O2 on protein modification and oxidation. Additionally, we attempted molecular docking approaches to check the action of D2O2 on the apoptosis related genes. Further, we confirmed the formation of OD/OH simultaneously in the solution using optical emission spectroscopy. Moreover, the simultaneous generation of D2O2/H2O2 was detected by the use of confocal Raman spectroscopy and density measurements.

  18. Expertise seeking

    DEFF Research Database (Denmark)

    Hertzum, Morten

    2014-01-01

    Expertise seeking is the activity of selecting people as sources for consultation about an information need. This review of 72 expertise-seeking papers shows that across a range of tasks and contexts people, in particular work-group colleagues and other strong ties, are among the most frequently...... used sources. Studies repeatedly show the influence of the social network – of friendships and personal dislikes – on the expertise-seeking network of organisations. In addition, people are no less prominent than documentary sources, in work contexts as well as daily-life contexts. The relative...... influence of source quality and source accessibility on source selection varies across studies. Overall, expertise seekers appear to aim for sufficient quality, composed of reliability and relevance, while also attending to accessibility, composed of access to the source and access to the source information...

  19. When biomolecules meet graphene: from molecular level interactions to material design and applications.

    Science.gov (United States)

    Li, Dapeng; Zhang, Wensi; Yu, Xiaoqing; Wang, Zhenping; Su, Zhiqiang; Wei, Gang

    2016-12-01

    Graphene-based materials have attracted increasing attention due to their atomically-thick two-dimensional structures, high conductivity, excellent mechanical properties, and large specific surface areas. The combination of biomolecules with graphene-based materials offers a promising method to fabricate novel graphene-biomolecule hybrid nanomaterials with unique functions in biology, medicine, nanotechnology, and materials science. In this review, we focus on a summarization of the recent studies in functionalizing graphene-based materials using different biomolecules, such as DNA, peptides, proteins, enzymes, carbohydrates, and viruses. The different interactions between graphene and biomolecules at the molecular level are demonstrated and discussed in detail. In addition, the potential applications of the created graphene-biomolecule nanohybrids in drug delivery, cancer treatment, tissue engineering, biosensors, bioimaging, energy materials, and other nanotechnological applications are presented. This review will be helpful to know the modification of graphene with biomolecules, understand the interactions between graphene and biomolecules at the molecular level, and design functional graphene-based nanomaterials with unique properties for various applications.

  20. A Video Game Promoting Cancer Risk Perception and Information Seeking Behavior Among Young-Adult College Students: A Randomized Controlled Trial

    Science.gov (United States)

    Beale, Ivan L; Chen, Minxing; Prokhorov, Alexander V

    2016-01-01

    Background Risky behaviors tend to increase drastically during the transition into young adulthood. This increase may ultimately facilitate the initiation of carcinogenic processes at a young age, highlighting a serious public health problem. By promoting information seeking behavior (ISB), young adults may become aware of cancer risks and potentially take preventive measures. Objective Based on the protection motivation theory, the current study seeks to evaluate the impact of challenge in a fully automated video game called Re-Mission on young adult college students' tendency to perceive the severity of cancer, feel susceptible to cancer, and engage in ISB. Methods A total of 216 young adults were recruited from a university campus, consented, screened, and randomized in a single-blinded format to 1 of 3 conditions: an intervention group playing Re-Mission at high challenge (HC; n=85), an intervention group playing Re-Mission at low challenge (LC; n=81), and a control group with no challenge (NC; presented with illustrated pictures of Re-Mission; n=50). Measurement was conducted at baseline, immediate posttest, 10-day follow-up, and 20-day follow-up. Repeated-measures mixed-effect models were conducted for data analysis of the main outcomes. Results A total of 101 young adults continued until 20-day follow-up. Mixed-effect models showed that participants in the HC and LC groups were more likely to increase in perceived susceptibility to cancer (P=.03), perceived severity of cancer (P=.02), and ISB (P=.01) than participants in the NC group. The LC group took until 10-day follow-up to show increase in perceived susceptibility (B=0.47, standard error (SE) 0.16, P=.005). The HC group showed an immediate increase in perceived susceptibility at posttest (B=0.43, SE 0.14, P=.002). The LC group exhibited no changes in perceived severity (B=0.40, SE 0.33, P=.24). On the other hand, the HC group showed a significant increase from baseline to posttest (B=0.39, SE 0.14, P

  1. The health seeking trajectories of Malaysian women and their husbands in delay cases of breast cancer: a qualitative study.

    Science.gov (United States)

    Yusoff, Nasir; Taib, Nur Aishah Mohd; Ahmad, Aini

    2011-01-01

    The aim of this study was to assess why women delay in getting treatment (i.e. surgery) for breast cancer, as well as to explore on what type of issues are involved in such delay cases. Basic interpretative of qualitative methodology was applied to construct the reality of delay phenomena, and its interaction with social worlds. Six themes were identified: new conception of breast cancer treatment, psychological defenses, health support system, symtomatology experience, model and barriers. The delay issue in breast cancer requires attention as a multidimensional problem as this will facilitate more comprehensive and effective intervention to reduce delay.

  2. Biomolecule-based nanomaterials and nanostructures.

    Science.gov (United States)

    Willner, Itamar; Willner, Bilha

    2010-10-13

    Biomolecule-nanoparticle (or carbon nanotube) hybrid systems provide new materials that combine the unique optical, electronic, or catalytic properties of the nanoelements with the recognition or biocatalytic functions of biomolecules. This article summarizes recent applications of biomolecule-nanoparticle (or carbon nanotubes) hybrid systems for sensing, synthesis of nanostructures, and for the fabrication of nanoscale devices. The use of metallic nanoparticles for the electrical contacting of redox enzymes with electrodes, and as catalytic labels for the development of electrochemical biosensors is discussed. Similarly, biomolecule-quantum dot hybrid systems are implemented for optical biosensing, and for monitoring intracellular metabolic processes. Also, the self-assembly of biomolecule-metal nanoparticle hybrids into nanostructures and functional nanodevices is presented. The future perspectives of the field are addressed by discussing future challenges and highlighting different potential applications.

  3. Awareness of cancer symptoms and anticipated patient interval for healthcare seeking. A comparative study of Denmark and Sweden.

    Science.gov (United States)

    Hvidberg, Line; Lagerlund, Magdalena; Pedersen, Anette F; Hajdarevic, Senada; Tishelman, Carol; Vedsted, Peter

    2016-07-01

    Background Recent epidemiologic data show that Denmark has considerably poorer survival from common cancers than Sweden. This may be related to a lower awareness of cancer symptoms and longer patient intervals in Denmark than in Sweden. The aims of this study were to: 1) compare population awareness of three possible symptoms of cancer (unexplained lump or swelling, unexplained bleeding and persistent cough or hoarseness); 2) compare anticipated patient interval when noticing any breast changes, rectal bleeding and persistent cough; and 3) examine whether potential differences were noticeable in particular age groups or at particular levels of education in a Danish and Swedish population sample. Method Data were derived from Module 2 of the International Cancer Benchmarking Partnership. Telephone interviews using the Awareness and Beliefs about Cancer measure were conducted in 2011 among 3000 adults in Denmark and 3070 adults in Sweden. Results Danish respondents reported a higher awareness of two of three symptoms (i.e. unexplained lump or swelling and persistent cough or hoarseness) and a shorter anticipated patient interval for two of three symptoms studied (i.e. any breast changes and rectal bleeding) than Swedish respondents. Differences in symptom awareness and anticipated patient interval between these countries were most pronounced in highly educated respondents. Conclusion Somewhat paradoxically, the highest awareness of symptoms of cancer and the shortest anticipated patient intervals were found in Denmark, where cancer survival is lower than in Sweden. Thus, it appears that these differences in symptom awareness and anticipated patient interval do not help explain the cancer survival disparity between Denmark and Sweden.

  4. Nanobiodevices for Biomolecule Analysis and Imaging

    Science.gov (United States)

    Yasui, Takao; Kaji, Noritada; Baba, Yoshinobu

    2013-06-01

    Nanobiodevices have been developed to analyze biomolecules and cells for biomedical applications. In this review, we discuss several nanobiodevices used for disease-diagnostic devices, molecular imaging devices, regenerative medicine, and drug-delivery systems and describe the numerous advantages of nanobiodevices, especially in biological, medical, and clinical applications. This review also outlines the fabrication technologies for nanostructures and nanomaterials, including top-down nanofabrication and bottom-up molecular self-assembly approaches. We describe nanopillar arrays and nanowall arrays for the ultrafast separation of DNA or protein molecules and nanoball materials for the fast separation of a wide range of DNA molecules, and we present examples of applications of functionalized carbon nanotubes to obtain information about subcellular localization on the basis of mobility differences between free fluorophores and fluorophore-labeled carbon nanotubes. Finally, we discuss applications of newly synthesized quantum dots to the screening of small interfering RNA, highly sensitive detection of disease-related proteins, and development of cancer therapeutics and diagnostics.

  5. Selective information seeking: can consumers' avoidance of evidence-based information on colorectal cancer screening be explained by the theory of cognitive dissonance?

    Directory of Open Access Journals (Sweden)

    Mühlhauser, Ingrid

    2007-08-01

    Full Text Available Background: Evidence-based patient information (EBPI is a prerequisite for informed decision-making. However, presentation of EBPI may lead to irrational reactions causing avoidance, minimisation and devaluation of the information. Objective: To explore whether the theory of cognitive dissonance is applicable to medical decision-making and useful to explain these phenomena. Setting and participants: 261 volunteers from Hamburg (157 women, ≥50 years old without diagnosis of colorectal cancer. Design and variables: Within an experiment we simulated information seeking on colorectal cancer screening. Consumers’ attitudes towards screening were surveyed using a rating scale from -5 (participate in no way to +5 (participate unconditionally (independent variable. Using a cover story, participants were asked to sort 5 article headlines according to their reading preferences. The headlines simulated the pro to contra variety of contents to be found in print media about colorectal cancer screening. The dependent variable was the sequence of article headlines. Results: Participants were very much in favour of screening with scores for faecal occult blood test of 4.0 (0.1 and for colonoscopy 3.3 (0.1. According to our hypothesis we found statistically significant positive correlations between the stimuli in favour of screening and attitudes and significant negative correlations between the stimuli against screening and attitudes. Conclusion: The theory of cognitive dissonance is applicable to medical decision-making. It may explain some phenomena of irrational reactions to evidence-based patient information.

  6. Information Seeking and Satisfaction with Information Sources Among Spouses of Men with Newly Diagnosed Local-Stage Prostate Cancer.

    Science.gov (United States)

    Bansal, Aasthaa; Koepl, Lisel M; Fedorenko, Catherine R; Li, Chunyu; Smith, Judith Lee; Hall, Ingrid J; Penson, David F; Ramsey, Scott D

    2017-02-25

    Information sources about prostate cancer treatment and outcomes are typically designed for patients. Little is known about the availability and utility of information for partners. The objectives of our study were to evaluate information sources used by partners to understand prostate cancer management options, their perceived usefulness, and the relationship between sources used and satisfaction with treatment experience. A longitudinal survey of female partners of men newly diagnosed with local-stage prostate cancer was conducted in three different geographic regions. Partners and associated patients were surveyed at baseline (after patient diagnosis but prior to receiving therapy) and at 12 months following diagnosis. Information sources included provider, literature, friends or family members, Internet websites, books, traditional media, and support groups. Utility of an information source was defined as whether the partner would recommend it to caregivers of other patients with local-stage prostate cancer. Our study cohort included 179 partner-patient pairs. At diagnosis, partners consulted an average of 4.6 information sources. Non-Hispanic white partners were more likely than others to use friends and family as an information source (OR = 2.44, 95% CI (1.04, 5.56)). More educated partners were less likely to use support groups (OR = 0.31, 95% CI (0.14, 0.71)). At 12-month follow-up, partners were less likely to recommend books (OR = 0.23, 95% CI (0.11, 0.49)) compared to baseline. Partners consulted a large number of information sources in researching treatment options for local-stage prostate cancer and the types of sources accessed varied by race/ethnicity and educational attainment. Additional resources to promote selection of high-quality non-provider information sources are warranted to enable partners to better aid patients in their treatment decision-making process.

  7. In situ hybridization of superparamagnetic iron-biomolecule nanoparticles.

    Science.gov (United States)

    Moghimi, Nafiseh; Donkor, Apraku David; Mohapatra, Mamata; Thomas, Joseph Palathinkal; Su, Zhengding; Tang, Xiaowu Shirley; Leung, Kam Tong

    2014-07-23

    The increase in interest in the integration of organic-inorganic nanostructures in recent years has promoted the use of hybrid nanoparticles (HNPs) in medicine, energy conversion, and other applications. Conventional hybridization methods are, however, often long, complicated, and multistepped, and they involve biomolecules and discrete nanostructures as separate entities, all of which hinder the practical use of the resulting HNPs. Here, we present a novel, in situ approach to synthesizing size-specific HNPs using Fe-biomolecule complexes as the building blocks. We choose an anticancer peptide (p53p, MW 1.8 kDa) and an enzyme (GOx, MW 160 kDa) as model molecules to demonstrate the versatility of the method toward different types of molecules over a large size range. We show that electrostatic interaction for complex formation of metal hydroxide ion with the partially charged side of biomolecule in the solution is the key to hybridization of metal-biomolecule materials. Electrochemical deposition is then used to produce hybrid NPs from these complexes. These HNPs with controllable sizes ranging from 30 nm to 3.5 μm are found to exhibit superparamagnetic behavior, which is a big challenge for particles in this size regime. As an example of greatly improved properties and functionality of the new hybrid material, in vitro toxicity assessment of Fe-GOx HNPs shows no adverse effect, and the Fe-p53p HNPs are found to selectively bind to cancer cells. The superparamagnetic nature of these HNPs (superparamagnetic even above the size regime of 15-20 nm!), their biocompatibility, and the direct integration approach are fundamentally important to biomineralization and general synthesis strategy for bioinspired functional materials.

  8. Seeking Mind, Body and Spirit Healing—Why Some Men with Prostate Cancer Choose CAM (Complementary and Alternative Medicine) over Conventional Cancer Treatments

    OpenAIRE

    Margaret A. White; Verhoef, Marja J.; B.J. Davison; Hal Gunn; Karen Cooke

    2008-01-01

    Little is known about men with prostate cancer who decline conventional treatment and use only complementary and alternative medicine (CAM). Objectives: To 1) explore why men decline conventional prostate cancer treatment and use CAM 2) understand the role of holistic healing in their care, and 3) document their recommendations for health care providers. Methods: Semi-structured interviews and follow-up focus groups. Sample: Twenty-nine men diagnosed with prostate cancer who declined all reco...

  9. Immobilizing Biomolecules Near the Diffraction Limit

    DEFF Research Database (Denmark)

    Skovsen, Esben; Petersen, Maria Teresa Neves; Gennaro, Ane Kold Di

    2009-01-01

    Our group has previously shown that biomolecules containing disulfide bridges in close proximity to aromatic residues can be immobilized, through covalent bonds, onto thiol derivatized surfaces upon UV excitation of the aromatic residue(s). We have also previously shown that our new technology can...... be used to print arrays of biomolecules and to immobilize biomolecules according to any specific pattern on a planar substrates with micrometer scale resolution. In this paper we show that we can immobilize proteins according to diffraction patterns of UV light. We also show that the feature size...... of the immobilized patterns can be as small as the diffraction limit for the excitation light, and that the immobilized patterns correspond to the diffraction pattern used to generate it. The flexibility of this new technology will in principle make it possible to create any pattern of biomolecules onto a substrate...

  10. Optoelectrofluidic Manipulation of Nanoparticles and Biomolecules

    Directory of Open Access Journals (Sweden)

    Hyundoo Hwang

    2011-01-01

    Full Text Available This paper presents optoelectrofluidic technologies for manipulation of nanoparticles and biomolecules. Optoelectrofluidics provides an elegant scheme for the programmable manipulation of particles or fluids in microenvironments based on optically induced electrokinetics. Recent progress on the optoelectrofluidic manipulation of nanoobjects, which include nanospheres, nanowires, nanotubes, and biomolecules, is introduced. Some potential applications of the optoelectrofluidic nanoparticle manipulation, such as nanoparticles separation, nanostructures manufacturing, molecular physics, and clinical diagnostics, and their future directions are also discussed.

  11. Biomolecule/nanomaterial hybrid systems for nanobiotechnology.

    Science.gov (United States)

    Tel-Vered, Ran; Yehezkeli, Omer; Willner, Itamar

    2012-01-01

    The integration of biomolecules with metallic or semiconductor nanoparticles or carbon nanotubes yields new hybrid nanostructures of unique features that combine the properties of the biomolecules and of the nano-elements. These unique features of the hybrid biomolecule/nanoparticle systems provide the basis for the rapid development of the area of nanobiotechnology. Recent advances in the implementation of hybrid materials consisting of biomolecules and metallic nanoparticles or semiconductor quantum dots will be discussed. The following topics will be exemplified: (i) The electrical wiring of redox enzymes with electrodes by means of metallic nanoparticles or carbon nanotubes, and the application of the modified electrodes as amperometric biosensors or for the construction of biofuel cells. (ii) The biocatalytic growth of metallic nanoparticles as a means to construct optical or electrical sensors. (iii) The functionalization of semiconductor quantum dots with biomolecules and the application of the hybrid nanostructures for developing different optical sensors, including intracellular sensor systems. (iv) The use of biomolecule-metallic nanoparticle nanostructures as templates for growing metallic nanowires, and the construction of fuel-driven nano-transporters.

  12. Seeking Mind, Body and Spirit Healing—Why Some Men with Prostate Cancer Choose CAM (Complementary and Alternative Medicine over Conventional Cancer Treatments

    Directory of Open Access Journals (Sweden)

    Margaret A. White

    2008-01-01

    Full Text Available Little is known about men with prostate cancer who decline conventional treatment and use only complementary and alternative medicine (CAM.Objectives: To 1 explore why men decline conventional prostate cancer treatment and use CAM 2 understand the role of holistic healing in their care, and 3 document their recommendations for health care providers.Methods: Semi-structured interviews and follow-up focus groups.Sample: Twenty-nine men diagnosed with prostate cancer who declined all recommended conventional treatments and used CAM.Results: Based on strong beliefs about healing, study participants took control by researching the risks of delaying or declining conventional treatment while using CAM as a first option. Most perceived conventional treatment to have a negative impact on quality of life. Participants sought healing in a broader mind, body, spirit context, developing individualized CAM approaches consistent with their beliefs about the causes of cancer. Most made significant lifestyle changes to improve their health. Spirituality was central to healing for one-third of the sample. Participants recommended a larger role for integrated cancer care.Conclusion: Men who decline conventional prostate cancer treatment and use CAM only may benefit from a whole person approach to care where physicians support them to play an active role in healing while carefully monitoring their disease status.

  13. Biomolecule-coated metal nanoparticles on titanium.

    Science.gov (United States)

    Christensen, Stephen L; Chatt, Amares; Zhang, Peng

    2012-02-07

    Immobilizations of nanoparticles and biomolecules on biocompatible substrates such as titanium are two promising approaches to bringing new functionalities to Ti-based biomaterials. Herein, we used a variety of X-ray spectroscopic techniques to study and better understand metal-thiolate interactions in biofunctionalized metal nanoparticle systems supported on Ti substrates. Using a facile one-step procedure, a series of Au nanoparticle samples with varied biomolecule coatings ((2-mercatopropionyl)glycine (MPG) and bovine serum albumin (BSA)) and biomolecule concentrations are prepared. Ag and Pd systems are also studied to observe change with varying metal composition. The structure and properties of these biomolecule-coated nanoparticles are investigated with scanning electron microscopy (SEM) and element-specific X-ray techniques, including extended X-ray absorption fine structure (Au L(3)-edge), X-ray absorption near-edge structure (Au L(3), Ag L(3), Pd L(3), and S K-edge), and X-ray photoelectron spectroscopy (Au 4f, Ag 3d, Pd 3d, and S 2p core level). It was found that, by comparison of SEM and X-ray spectroscopy results, the coating of metal nanoparticles with varying model biomolecule systems can have a significant effect on both surface coverage and organization. This work offers a facile chemical method for bio- and nanofunctionalization of Ti substrates as well as provides a physical picture of the structure and bonding of biocoated metal nanoparticles, which may lead to useful applications in orthopedics and biomedicine.

  14. Biomolecules for removal of heavy metal.

    Science.gov (United States)

    Singh, Namita Ashish

    2017-02-23

    Heavy metals are natural constituents of the earth's crust, but some heavy metals like cadmium, lead, mercury, arsenic etc. are injurious to living organisms at higher concentration. Nowadays, anthropogenic activities have altered geochemical cycles and biochemical balance of heavy metals. Biomolecules are used nowadays for removal of heavy metals compared to other synthetic biosorbents due to their environmental friendly nature and cost effectiveness. The goal of this work is to review research work and patents related to adsorption through biomolecules like polysaccharides, polypeptides, lignin etc. and bio-sorption by biological material that are used for heavy metal removal. Biomolecules are cost effective and there have been significant progresses in the remediation of heavy metals but, still there are some problems that need to be rectified for its application at industrial processes.

  15. On the thermodynamics of biomolecule surface transformations.

    Science.gov (United States)

    Federici, Stefania; Oliviero, Giulio; Maiolo, Daniele; Depero, Laura E; Colombo, Italo; Bergese, Paolo

    2012-06-01

    Biological surface science is receiving great and renewed attention owing the rising interest in applications of nanoscience and nanotechnology to biological systems, with horizons that range from nanomedicine and biomimetic photosynthesis to the unexpected effects of nanomaterials on health and environment. Biomolecule surface transformations are among the fundamental aspects of the field that remain elusive so far and urgently need to be understood to further the field. Our recent findings indicate that surface thermodynamics can give a substantial contribution toward this challenging goal. In the first part of the article, we show that biomolecule surface transformations can be framed by a general and simple thermodynamic model. Then, we explore its effectiveness by addressing some typical cases, including ligand-receptor surface binding, protein thin film machines, nanomechanical aspects of the biomolecule-nanoparticle interface and nanomechanical biosensors.

  16. Microorganisms and biomolecules in space hard environment

    Science.gov (United States)

    Horneck, G.

    1981-01-01

    Microorganisms and biomolecules exposed to space vacuum and to different intensities of selected wavelengths of solar ultraviolet radiation is studied. The influence of these factors, applied singly or simultaneously, on the integrity of microbial systems and biomolecules is measured. Specifically, this experiment will study in Bacillus subtilis spores (1) disturbances in subsequent germination, outgrowth, and colony formation; (2) photochemical reactions of the DNA and protein in vivo and in vitro and their role in biological injury; and (3) the efficiency of repair processes in these events.

  17. A Multidisciplinary, Open Access Platform for Research on Biomolecules.

    Science.gov (United States)

    Bähler, Jürg

    2011-08-22

    I am pleased to introduce Biomolecules, a new journal to report on all aspects of science that focuses on biologically derived substances, from small molecules to complex polymers. Some examples are lipids, carbohydrates, vitamins, hormones, amino acids, nucleotides, peptides, RNA and polysaccharides, but this list is far from exhaustive. Research on biomolecules encompasses multiple fascinating questions. How are biomolecules synthesized and modified? What are their structures and interactions with other biomolecules? How do biomolecules function in biological processes, at the level of organelles, cells, organs, organisms, or even ecosystems? How do biomolecules affect either the organism that produces them or other organisms of the same or different species? How are biomolecules shaped by evolution, and how in turn do they affect cellular phenotypes? What is the systems-level contribution of biomolecules to biological function? [...].

  18. A Multidisciplinary, Open Access Platform for Research on Biomolecules

    Directory of Open Access Journals (Sweden)

    Jürg Bähler

    2011-08-01

    Full Text Available I am pleased to introduce Biomolecules, a new journal to report on all aspects of science that focuses on biologically derived substances, from small molecules to complex polymers. Some examples are lipids, carbohydrates, vitamins, hormones, amino acids, nucleotides, peptides, RNA and polysaccharides, but this list is far from exhaustive. Research on biomolecules encompasses multiple fascinating questions. How are biomolecules synthesized and modified? What are their structures and interactions with other biomolecules? How do biomolecules function in biological processes, at the level of organelles, cells, organs, organisms, or even ecosystems? How do biomolecules affect either the organism that produces them or other organisms of the same or different species? How are biomolecules shaped by evolution, and how in turn do they affect cellular phenotypes? What is the systems-level contribution of biomolecules to biological function?

  19. Nanofluidic technology for biomolecule applications: a critical review

    NARCIS (Netherlands)

    Napoli, M.; Eijkel, J.C.T.; Pennathur, S.

    2010-01-01

    In this review, we present nanofluidic phenomena, particularly as they relate to applications involving analysis of biomolecules within nanofabricated devices. The relevant length scales and physical phenomena that govern biomolecule transport and manipulation within nanofabricated nanofluidic devic

  20. Tuneable graphene nanopores for single biomolecule detection

    Science.gov (United States)

    Al-Dirini, Feras; Mohammed, Mahmood A.; Hossain, Md Sharafat; Hossain, Faruque M.; Nirmalathas, Ampalavanapillai; Skafidas, Efstratios

    2016-05-01

    Solid-state nanopores are promising candidates for next generation DNA and protein sequencing. However, once fabricated, such devices lack tuneability, which greatly restricts their biosensing capabilities. Here we propose a new class of solid-state graphene-based nanopore devices that exhibit a unique capability of self-tuneability, which is used to control their conductance, tuning it to levels comparable to the changes caused by the translocation of a single biomolecule, and hence, enabling high detection sensitivities. Our presented quantum simulation results suggest that the smallest amino acid, glycine, when present in water and in an aqueous saline solution can be detected with high sensitivity, up to a 90% change in conductance. Our results also suggest that passivating the device with nitrogen, making it an n-type device, greatly enhances its sensitivity, and makes it highly sensitive to not only the translocation of a single biomolecule, but more interestingly to intramolecular electrostatics within the biomolecule. Sensitive detection of the carboxyl group within the glycine molecule, which carries a charge equivalent to a single electron, is achieved with a conductance change that reaches as high as 99% when present in an aqueous saline solution. The presented findings suggest that tuneable graphene nanopores, with their capability of probing intramolecular electrostatics, could pave the way towards a new generation of single biomolecule detection devices.

  1. Porous-wall hollow glass microspheres as carriers for biomolecules

    Science.gov (United States)

    Li, Shuyi; Dynan, William S; Wicks, George; Serkiz, Steven

    2013-09-17

    The present invention includes compositions of porous-wall hollow glass microspheres and one or more biomolecules, wherein the one or more biomolecules are positioned within a void location within the hollow glass microsphere, and the use of such compositions for the diagnostic and/or therapeutic delivery of biomolecules.

  2. Survey of the Information-Seeking Behaviour of Hospital Professionals at a Public Cancer Hospital in Greece Proves the Value of Hospital Libraries. A Review of: Kostagiolas, P. A., Ziavrou, K., Alexias, G., & Niakas, D. (2012. Studying the information-seeking behavior of hospital professionals: The case of METAXA Cancer Hospital in Greece. Journal of Hospital Librarianship, 12(1, 33-45.

    Directory of Open Access Journals (Sweden)

    Antonio DeRosa

    2013-06-01

    Full Text Available Objective – To study the information-seeking practices of hospital staff and weigh the impact of hospital libraries on effective information-seeking.Design – Survey questionnaire.Setting – Large public cancer hospital in Greece.Subjects – The authors surveyed 49 physicians, 43 nursing staff members, 25 administrative staff members, 23 paramedical staff members, and 5 technical staff members, totaling 145 health professionals.Methods – Participants were given a questionnaire comprised of five parts: general information (including gender, age, education, position, and professional experience; questions on computer and Internet accessibility; questions regarding individual information needs; questions on information-seeking obstacles; and a question regarding the satisfaction with the current degree of information availability in the hospital. The last question was ranked using a 5-point Likert scale. Each questionnaire was distributed with a cover letter explaining the anonymity and consent of the respondent. Hospital members were randomly selected using a number generator and respondents returned completed surveys to the hospital personnel office in a sealed envelope within a specified time frame. The sampled group was representative of the overall population of the hospital.Main Results – The authors discuss demographic data of respondents: 65.7% were women; 56.7% were over 40 years old; 29.0% were graduates of higher technological institutes; 28.3% were university graduates; 9.7% held a postgraduate degree; 8.3% had a PhD; and 1.4% had only secondary education. As for the remainder of the survey questions: 64% of respondents had access to the Internet both at home and at work, while only 8.2% had no access to the Internet at all; most respondents noted using the Internet for seeking scientific information (83.0% and e-mail communication (65.3%; the main obstacle respondents noted experiencing when seeking information was the lack of

  3. Bone-seeking therapeutic radiopharmaceuticals

    Directory of Open Access Journals (Sweden)

    Srivastava Suresh C.

    2002-01-01

    Full Text Available Bone-seeking therapeutic radiopharmaceuticals are utilized on the basis of the radionuclide?s particulate emissions (primarily low to intermediate beta emission. The requirements therefore are different from those of bone imaging agents that consist mainly of short-lived single photon emitters. Lately, the therapeutic bone seeking radiopharmaceuticals have attained increasing importance due to their potential role in alleviating pain from osseous metastases in cancer patients, for the treatment of joint pain resulting from inflamed synovium (radiosynoviorthesis, or radiosynovectomy, or from various other forms of arthritic disease. There is, however, a paucity of published data on the bio-pharmacokinetics of these agents when used following intravenous administration for bone pain palliation. This paper will briefly review and summarize the presently available chemical and biopharmacokinetic information on the various clinically approved as well as experimental bone-localizing therapeutic radiopharmaceuticals, and make projections on their clinical application for the treatment of primary/metastatic cancer in bone.

  4. Fed-Batch Biomolecule Production by Bacillus subtilis: A State of the Art Review.

    Science.gov (United States)

    Öztürk, Sibel; Çalık, Pınar; Özdamar, Tunçer H

    2016-04-01

    Bacillus subtilis is a highly promising production system for various biomolecules. This review begins with the algorithm of fed-batch operations (FBOs) and then illustrates the approaches to design the initial production medium and/or feed stream. Additionally, the feeding strategies developed with or without feedback control for fed-batch B. subtilis fermentations were compiled with a special emphasis on recombinant protein (r-protein) production. For biomolecule production by wild-type B. subtilis, due to the different intracellular production patterns, no consensus exists on the FBO strategy that gives the maximum productivity, whereas for r-protein production appropriate feeding strategies vary depending on the promoter used. Thus, we conclude that the B. subtilis community is still seeking an approved strong promoter and generalized FBO strategies.

  5. Biomolecule Profiles in Inedible Wild Mushrooms with Antioxidant Value

    Directory of Open Access Journals (Sweden)

    Isabel C.F.R. Ferreira

    2011-05-01

    Full Text Available The use of natural products isolated from mushrooms, included inedible species, against infection, cancer diseases and other oxidative-stress related diseases is one of the cornerstones of modern medicine. In the present work, the antioxidant molecule profiles of inedible mushroom species were evaluated and compared with those of edible species. The order of antioxidant abundance found in inedible wild mushrooms was: phenolics > flavonoids > ascorbic acid > tocopherols > carotenoids, similar to that of edible species. Furthermore the same energetic biomolecules were found including the disaccharide trehalose, the monosaccharide alcohol derivative mannitol and the fatty acids palmitic, oleic and linoleic acids. Fomitopsis pinicola revealed a very high phenolics concentration (388 mg GAE/g extract and powerful antioxidant properties, mainly reducing power (EC50 value 60 μg/mL similar to the standard Trolox®. It could find applications in the prevention of free radical-related diseases as a source of bioactive compounds.

  6. Biomolecule delivery to engineer the cellular microenvironment for regenerative medicine.

    Science.gov (United States)

    Bishop, Corey J; Kim, Jayoung; Green, Jordan J

    2014-07-01

    To realize the potential of regenerative medicine, controlling the delivery of biomolecules in the cellular microenvironment is important as these factors control cell fate. Controlled delivery for tissue engineering and regenerative medicine often requires bioengineered materials and cells capable of spatiotemporal modulation of biomolecule release and presentation. This review discusses biomolecule delivery from the outside of the cell inwards through the delivery of soluble and insoluble biomolecules as well as from the inside of the cell outwards through gene transfer. Ex vivo and in vivo therapeutic strategies are discussed, as well as combination delivery of biomolecules, scaffolds, and cells. Various applications in regenerative medicine are highlighted including bone tissue engineering and wound healing.

  7. Monitoring the synthesis of biomolecules using mass spectrometry.

    Science.gov (United States)

    Miyagi, Masaru; Kasumov, Takhar

    2016-10-28

    The controlled and selective synthesis/clearance of biomolecules is critical for most cellular processes. In most high-throughput 'omics' studies, we measure the static quantities of only one class of biomolecules (e.g. DNA, mRNA, proteins or metabolites). It is, however, important to recognize that biological systems are highly dynamic in which biomolecules are continuously renewed and different classes of biomolecules interact and affect each other's production/clearance. Therefore, it is necessary to measure the turnover of diverse classes of biomolecules to understand the dynamic nature of biological systems. Herein, we explain why the kinetic analysis of a diverse range of biomolecules is important and how such an analysis can be done. We argue that heavy water ((2)H2O) could be a universal tracer for monitoring the synthesis of biomolecules on a global scale.This article is part of the themed issue 'Quantitative mass spectrometry'.

  8. Collaborative information seeking

    DEFF Research Database (Denmark)

    Hertzum, Morten

    2008-01-01

    , the activities involved in information seeking are often performed by varying subgroups of actors. Consequently, collaborative grounding is necessary to share information among collaborating actors and, thereby, establish and maintain the common ground necessary for their collaborative work. By focusing......Since common ground is pivotal to collaboration, this paper proposes to define collaborative information seeking as the combined activity of information seeking and collaborative grounding. While information-seeking activities are necessary for collaborating actors to acquire new information...... on the collaborative level, collaborative information seeking aims to avoid both individual reductionism and group reductionism, while at the same time recognizing that only some information and understanding need be shared....

  9. Biomolecule immobilization techniques for bioactive paper fabrication.

    Science.gov (United States)

    Kong, Fanzhi; Hu, Yim Fun

    2012-04-01

    Research into paper-based sensors or functional materials that can perform analytical functions with active recognition capabilities is rapidly expanding, and significant research effort has been made into the design and fabrication of bioactive paper at the biosensor level to detect potential health hazards. A key step in the fabrication of bioactive paper is the design of the experimental and operational procedures for the immobilization of biomolecules such as antibodies, enzymes, phages, cells, proteins, synthetic polymers and DNA aptamers on a suitably prepared paper membrane. The immobilization methods are concisely categorized into physical absorption, bioactive ink entrapment, bioaffinity attachment and covalent chemical bonding immobilization. Each method has individual immobilization characteristics. Although every biomolecule-paper combination has to be optimized before use, the bioactive ink entrapment method is the most commonly used approach owing to its general applicability and biocompatibility. Currently, there are four common applications of bioactive paper: (1) paper-based bioassay or paper-based analytical devices for sample conditioning; (2) counterfeiting and countertempering in the packaging and construction industries; (3) pathogen detection for food and water quality monitoring; and (4) deactivation of pathogenic bacteria using antimicrobial paper. This article reviews and compares the different biomolecule immobilization techniques and discusses current trends. Current, emerging and future applications of bioactive paper are also discussed.

  10. Metal Stable Isotope Tagging: Renaissance of Radioimmunoassay for Multiplex and Absolute Quantification of Biomolecules.

    Science.gov (United States)

    Liu, Rui; Zhang, Shixi; Wei, Chao; Xing, Zhi; Zhang, Sichun; Zhang, Xinrong

    2016-05-17

    is the development and application of the mass cytometer, which fully exploited the multiplexing potential of metal stable isotope tagging. It realized the simultaneous detection of dozens of parameters in single cells, accurate immunophenotyping in cell populations, through modeling of intracellular signaling network and undoubted discrimination of function and connection of cell subsets. Metal stable isotope tagging has great potential applications in hematopoiesis, immunology, stem cells, cancer, and drug screening related research and opened a post-fluorescence era of cytometry. Herein, we review the development of biomolecule quantification using metal stable isotope tagging. Particularly, the power of multiplex and absolute quantification is demonstrated. We address the advantages, applicable situations, and limitations of metal stable isotope tagging strategies and propose suggestions for future developments. The transfer of enzymatic or fluorescent tagging to metal stable isotope tagging may occur in many aspects of biological and clinical practices in the near future, just as the revolution from radioactive isotope tagging to fluorescent tagging happened in the past.

  11. Newcomer information seeking

    DEFF Research Database (Denmark)

    Moring, Camilla Elisabeth

    2017-01-01

    Introduction: Research on socialization and learning processes among organizational newcomers is offering valuable insight into the role of information seeking in the workplace, and to why, and how newcomers seek information when entering a new organization. Analysis: The aim of the paper...... is to outline and discuss the significance of information seeking in newcomer socialization and learning, and analyse how different approaches influence our understanding of the role of information seeking in the workplace. Results: It is argued, that a development in research on newcomer information seeking...... in organizations newcomers access to participate and negotiate meaning in practice becomes essential. Information seeking hereby plays a significant role in newcomers learning by establishing, developing, and maintaining a relationship to a given organizational practice. Through accessing textual, social...

  12. Porous solid ion exchange wafer for immobilizing biomolecules

    Science.gov (United States)

    Arora, Michelle B.; Hestekin, Jamie A.; Lin, YuPo J.; St. Martin, Edward J.; Snyder, Seth W.

    2007-12-11

    A porous solid ion exchange wafer having a combination of a biomolecule capture-resin and an ion-exchange resin forming a charged capture resin within said wafer. Also disclosed is a porous solid ion exchange wafer having a combination of a biomolecule capture-resin and an ion-exchange resin forming a charged capture resin within said wafer containing a biomolecule with a tag. A separate bioreactor is also disclosed incorporating the wafer described above.

  13. Site-Specific Biomolecule Labeling with Gold Clusters

    OpenAIRE

    Ackerson, Christopher J.; Powell, Richard D.; Hainfeld, James F.

    2010-01-01

    Site-specific labeling of biomolecules in vitro with gold clusters can enhance the information content of electron cryomicroscopy experiments. This chapter provides a practical overview of well-established techniques for forming biomolecule/gold cluster conjugates. Three bioconjugation chemistries are covered: Linker-mediated bioconjugation, direct gold–biomolecule bonding, and coordination-mediated bonding of nickel(II) nitrilotriacetic acid (NTA)-derivatized gold clusters to polyhistidine (...

  14. Immobilization of biomolecules on semiconductor surfaces

    Science.gov (United States)

    Joensson, U.; Malmqvist, M.; Nilsson, H.; Olofsson, G.; Roennberg, I.

    1983-09-01

    A reproducible, stable and functional introduction of reactive groups on oxide covered silicon surfaces used in chemically sensitive field effect transistors and optical methods based on light reflection is described. Biomolecules, such as antibodies, antigens and enzymes, were covalently attached to the surface modified silicon via a thiol disulfide exchange reaction. The immobilization technique eliminates the risk of crosslinking and homopolymerization, giving monolayer coverage in close contact with the surface. The technique was used for immobilized protein A and interaction of such surfaces with immunoglobulins. The result was evaluated by in situ ellipsometry, which gives the amount of immobilized and interacting material on the surfaces.

  15. Cell-selective metabolic labeling of biomolecules with bioorthogonal functionalities.

    Science.gov (United States)

    Xie, Ran; Hong, Senlian; Chen, Xing

    2013-10-01

    Metabolic labeling of biomolecules with bioorthogonal functionalities enables visualization, enrichment, and analysis of the biomolecules of interest in their physiological environments. This versatile strategy has found utility in probing various classes of biomolecules in a broad range of biological processes. On the other hand, metabolic labeling is nonselective with respect to cell type, which imposes limitations for studies performed in complex biological systems. Herein, we review the recent methodological developments aiming to endow metabolic labeling strategies with cell-type selectivity. The cell-selective metabolic labeling strategies have emerged from protein and glycan labeling. We envision that these strategies can be readily extended to labeling of other classes of biomolecules.

  16. Automated astatination of biomolecules - a stepping stone towards multicenter clinical trials

    DEFF Research Database (Denmark)

    Aneheim, Emma; Albertsson, Per; Bäck, Tom

    2015-01-01

    and physical properties for use in targeted therapies for cancer. Due to the very short range of the emitted α-particles, this therapy is particularly suited to treating occult, disseminated cancers. Astatine is not intrinsically tumour-specific; therefore, it requires an appropriate tumour-specific targeting......To facilitate multicentre clinical studies on targeted alpha therapy, it is necessary to develop an automated, on-site procedure for conjugating rare, short-lived, alpha-emitting radionuclides to biomolecules. Astatine-211 is one of the few alpha-emitting nuclides with appropriate chemical...

  17. Thermally modulated biomolecule transport through nanoconfined channels.

    Science.gov (United States)

    Liu, Lei; Zhu, Lizhong

    2015-01-01

    In this work, a nanofluidic device containing both a feed cell and a permeation cell linked by nanopore arrays has been fabricated, which is employed to investigate thermally controlled biomolecular transporting properties through confined nanochannels. The ionic currents modulated by the translocations of goat antibody to human immunoglobulin G (IgG) or bovine serum albumin (BSA) are recorded and analyzed. The results suggest that the modulation effect decreases with the electrolyte concentration increasing, while the effects generated by IgG translocation are more significant than that generated by BSA translocation. More importantly, there is a maximum decreasing value in each modulated current curve with biomolecule concentration increasing for thermally induced intermolecular collision. Furthermore, the turning point for the maximum shifts to lower biomolecule concentrations with the system temperature rising (from 4°C to 45°C), and it is mainly determined by the temperature in the feed cell if the temperature difference exists in the two separated cells. These findings are expected to be valuable for the future design of novel sensing device based on nanopore and/or nanopore arrays.

  18. Cancer

    Science.gov (United States)

    ... cancer Non-Hodgkin lymphoma Ovarian cancer Pancreatic cancer Testicular cancer Thyroid cancer Uterine cancer Symptoms Symptoms of cancer ... tumor Obesity Pancreatic cancer Prostate cancer Stomach cancer Testicular cancer Throat or larynx cancer Thyroid cancer Patient Instructions ...

  19. Reaction between protein radicals and other biomolecules

    DEFF Research Database (Denmark)

    Østdal, Henrik; Davies, Michael Jonathan; Andersen, Henrik J

    2002-01-01

    oil-in-water emulsion resulted in additional formation of lipid hydroperoxides and conjugated dienes. The results clearly show that protein radicals have to be considered as dynamic species during oxidative processes in biological systems and that protein radicals should not be considered as end-products......The present study investigates the reactivity of bovine serum albumin (BSA) radicals towards different biomolecules (urate, linoleic acid, and a polypeptide, poly(Glu-Ala-Tyr)). The BSA radical was formed at room temperature through a direct protein-to-protein radical transfer from H(2)O(2....... Subsequent analysis showed a decrease in the concentration of urate upon reaction with the BSA radical, while the BSA radical in the presence of poly(Glu-Ala-Tyr) resulted in increased formation of the characteristic protein oxidation product, dityrosine. Reaction between the BSA radical and a linoleic acid...

  20. Teaching information seeking

    Directory of Open Access Journals (Sweden)

    Louise Limberg

    2006-01-01

    Full Text Available Introduction. The article argues for a closer association between information seeking research and the practices of teaching information seeking. Findings are presented from a research project on information seeking, didactics and learning (IDOL investigating librarians' and teachers' experiences of teaching information seeking. Method. Thirteen teachers and five librarians, teaching 12-19 year-old students in three schools, participated. Forty-five interviews were conducted over a period of three years. Analysis. The IDOL project adopted a phenomenographic approach with the purpose of describing patterns of variation in experiences. The findings were also analysed by way of relating them to four competing approaches to the mediation of information literacy. Results. A gap was identified between experiences of teaching content that focused on sources and order, and experiences of assessment criteria applied to students' work that focused on the importance of correct facts and the analysis of information. These findings indicate a highly restricted range of teaching contents when compared with the four theoretical approaches to the mediation of information literacy. Conclusion. Teaching information seeking might be enhanced by a wider repertoire of contents reflecting more varied theoretical understanding developed in information seeking research, particularly as regards the importance of content and context related to user perspectives.

  1. Small biomolecule immunosensing with plasmonic optical fiber grating sensor.

    Science.gov (United States)

    Ribaut, Clotilde; Voisin, Valérie; Malachovská, Viera; Dubois, Valentin; Mégret, Patrice; Wattiez, Ruddy; Caucheteur, Christophe

    2016-03-15

    This study reports on the development of a surface plasmon resonance (SPR) optical fiber biosensor based on tilted fiber Bragg grating technology for direct detection of small biomarkers of interest for lung cancer diagnosis. Since SPR principle relies on the refractive index modifications to sensitively detect mass changes at the gold coated surface, we have proposed here a comparative study in relation to the target size. Two cytokeratin 7 (CK7) samples with a molecular weight ranging from 78 kDa to 2.6 kDa, respectively CK7 full protein and CK7 peptide, have been used for label-free monitoring. This work has first consisted in the elaboration and the characterization of a robust and reproducible bioreceptor, based on antibody/antigen cross-linking. Immobilized antibodies were then utilized as binding agents to investigate the sensitivity of the biosensor towards the two CK7 antigens. Results have highlighted a very good sensitivity of the biosensor response for both samples diluted in phosphate buffer with a higher limit of detection for the larger CK7 full protein. The most groundbreaking nature of this study relies on the detection of small biomolecule CK7 peptides in buffer and in the presence of complex media such as serum, achieving a limit of detection of 0.4 nM.

  2. Ionic strength independence of charge distributions in solvation of biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Virtanen, J. J. [Department of Chemistry, University of Chicago, Chicago, Illinois 60637 (United States); James Franck Institute, University of Chicago, Chicago, Illinois 60637 (United States); Sosnick, T. R. [Department of Biochemistry and Molecular Biology, Institute for Biophysical Dynamics, University of Chicago, Chicago, Illinois 60637 (United States); Computation Institute, University of Chicago, Chicago, Illinois 60637 (United States); Freed, K. F. [Department of Chemistry, University of Chicago, Chicago, Illinois 60637 (United States); James Franck Institute, University of Chicago, Chicago, Illinois 60637 (United States); Computation Institute, University of Chicago, Chicago, Illinois 60637 (United States)

    2014-12-14

    Electrostatic forces enormously impact the structure, interactions, and function of biomolecules. We perform all-atom molecular dynamics simulations for 5 proteins and 5 RNAs to determine the dependence on ionic strength of the ion and water charge distributions surrounding the biomolecules, as well as the contributions of ions to the electrostatic free energy of interaction between the biomolecule and the surrounding salt solution (for a total of 40 different biomolecule/solvent combinations). Although water provides the dominant contribution to the charge density distribution and to the electrostatic potential even in 1M NaCl solutions, the contributions of water molecules and of ions to the total electrostatic interaction free energy with the solvated biomolecule are comparable. The electrostatic biomolecule/solvent interaction energies and the total charge distribution exhibit a remarkable insensitivity to salt concentrations over a huge range of salt concentrations (20 mM to 1M NaCl). The electrostatic potentials near the biomolecule's surface obtained from the MD simulations differ markedly, as expected, from the potentials predicted by continuum dielectric models, even though the total electrostatic interaction free energies are within 11% of each other.

  3. Radiation physics and chemistry of biomolecules. Recent developments

    Science.gov (United States)

    Spotheim-Maurizot, Melanie

    2016-11-01

    A chapter of the book ;Radiation chemistry. From basics to application in materials and life sciences (EDP Science, Paris, France, 2008); was devoted to the state-of-the-art in the research on ionizing radiation (IR) effects on biomolecules. An update, eight years later, seemed pertinent enough to the editors of this journal who accepted to dedicate a Special Issue to the latest developments in this area of high interest for cancer radiotherapy, nuclear workers' radioprotection and food radiosterilisation. We sincerely thank them and the authors who accepted to present reviews of their most recent work. Obviously, only a small part of the research in the fascinating domain of molecular radiobiology can be covered here. Some articles are presenting the contribution of biophysical models and computational techniques to the understanding of IR effects on molecules such as DNA and proteins, or on larger systems such as chromatin, chromosomes and even cells (Nikjoo et al., Štěpán & Davídková, Ballarini & Carante, and Nikitaki et al.). In these papers, as well as in many others, several qualities of IR are compared in order to explain the observed differences of effects. The damages induced by the low energy electrons and new techniques involved in their study are discussed in great detail (Sanche and Fromm & Boulanouar). The chemistry behind the IR induced damages (single or clustered), studied in many laboratories around the world is presented in several papers (Cadet & Wagner, Sevilla et al., Chatgilialoglu et al., and Greenberg). One of them addresses a very useful comparison between the effects of IR and UV exposure on DNA (Ravanat & Douki). The majority of the papers in this Special Issue is dealing with DNA and this reflects the real situation: damages of DNA are more studied than those of other biomolecules. This is due to the role of DNA as main support of hereditary information. Nevertheless, more and more studies are outlining the influence of epigenetic

  4. Biomolecule conjugation strategy using novel water-soluble phosphine-based chelating agents

    Science.gov (United States)

    Katti, Kattesh V.; Gali, Hariprasad; Volkert, Wynn A.

    2004-08-24

    This invention describes a novel strategy to produce phosphine-functionalized biomolecules (e.g. peptides or proteins) for potential use in the design and development of site-specific radiopharmaceuticals for diagnosis or therapy of specific cancers. Hydrophilic alkyl phosphines, in general, tend to be oxidatively unstable. Therefore, incorporation of such phosphine functionalities on peptide (and other biomolecule) backbones, without oxidizing the P.sup.III centers, is difficult. In this context this discovery reports on a new technology by which phosphines, in the form of bifunctional chelating agents, can be directly incorporated on biomolecular backbones using manual synthetic or solid phase peptide synthesis methodologies. The superior ligating abilities of phosphine ligands, with various diagnostically (e.g. TC-99m) or therapeutically (e.g. Re186/188, Rh-105, Au-199) useful radiometals, coupled with the findings that the resulting complexes demonstrate high in vivo stability makes this approach useful in the development of radiolabeled biomolecules for applications in the design of tumor-specific radiopharmaceuticals.

  5. Reducing, Maintaining, or Escalating Uncertainty? The Development and Validation of Four Uncertainty Preference Scales Related to Cancer Information Seeking and Avoidance.

    Science.gov (United States)

    Carcioppolo, Nick; Yang, Fan; Yang, Qinghua

    2016-09-01

    Uncertainty is a central characteristic of many aspects of cancer prevention, screening, diagnosis, and treatment. Brashers's (2001) uncertainty management theory details the multifaceted nature of uncertainty and describes situations in which uncertainty can both positively and negatively affect health outcomes. The current study extends theory on uncertainty management by developing four scale measures of uncertainty preferences in the context of cancer. Two national surveys were conducted to validate the scales and assess convergent and concurrent validity. Results support the factor structure of each measure and provide general support across multiple validity assessments. These scales can advance research on uncertainty and cancer communication by providing researchers with measures that address multiple aspects of uncertainty management.

  6. Noncovalent Labeling of Biomolecules with Red and Near- Infrared Dyes

    Directory of Open Access Journals (Sweden)

    Lucjan Strekowski

    2004-02-01

    Full Text Available Biopolymers such as proteins and nucleic acids can be labeled with a fluorescent marker to allow for their detection. Covalent labeling is achieved by the reaction of an appropriately functionalized dye marker with a reactive group on a biomolecule. The recent trend, however, is the use of noncovalent labeling that results from strong hydrophobic and/or ionic interactions between the marker and biomolecule of interest. The main advantage of noncovalent labeling is that it affects the functional activity of the biomolecule to a lesser extent. The applications of luminescent cyanine and squarylium dyes are reviewed.

  7. Information seeking behavior

    DEFF Research Database (Denmark)

    Hjørland, Birger

    2000-01-01

    A general theory of information seeking behaviour must include an outline of an evolutionary theory of how organisms have adapted their cognitive apparatus to the demands raised in order to cope with their environments. It should describe important qualitative stages in this development and explain...... the teleological or goal-oriented nature of the behaviour of living organisms. Such a theory should define the essential characteristics in human information seeking, including a description of it cultural and social determinants. It should consider the costs and benefits of information seeking, and the social...... mechanisms influencing its value. Further, such a theory should explain information neglecting and avoidance, the utilisation of different kinds of information resources, the strategies used, and their efficiency. A general theory should formulate what the essential, non-trivial factors are, which can...

  8. Biomolecule-mediated synthesis of nanocrystalline semiconductors

    Science.gov (United States)

    Bae, Weon

    CdS and ZnS nanocrystalline semiconductors (NCs) were prepared by titrating inorganic sulfide into preformed Cd(II)- or Zn(II)-complexes of phytochelatins, glutathione or cysteine. This strategy resulted in the formation NCs capped by the chosen biomolecule. The range of sizes and their distributions depended primarily on the quantity of sulfide titrated and the biomolecule chosen for the initial metallo-complex. The processes of NC formation were studied by absorption and fluorescence spectrophotometry. The size distribution was analyzed by gel permeation chromatography. Ethanol precipitation of NCs under aqueous conditions was used to isolate nanoparticles within a very narrow size-range. Reduction of selected dyes was also studied on the surfaces of NCs. Glutathione-capped CdS nanoparticles exhibited significant size heterogeneity even at a single sulfide titration. In contrast, phytochelatins showed much less dispersion in size at a given sulfide titration. Phytochelatins could replace glutathione without changing the size of glutathione-capped CdS nanoparticles. Cysteine appeared to be intermediate between glutathione and phytochelatins in the formation of CdS nanoparticles. The calculated radii, using an effective mass approximation method, were 10.8-17.3, 10.6-11.8, and 13.5-15.5A for glutathione-, phytochelatin-, and cysteine-capped CdS nanoparticles, respectively. Cysteine-capped ZnS showed narrower size distribution than glutathione-capped ZnS. However, elevated temperatures were necessary to accomplish optimal yields of cysteine-capped ZnS NCs. An additional control over the size distribution of NCs was achieved by size-selective precipitation with ethanol. These procedures led to the isolation of nanoparticles that were more uniform in size and chemical compositions as determined by spectroscopic and chemical analyses of size-fractionated samples. Precipitation also allowed preparation of large quantities of powdered nanoparticles that could be

  9. Self-perceived risk and barriers to cervical cancer screening among patients seeking care at a tertiary care teaching hospital in Tamil Nadu

    Directory of Open Access Journals (Sweden)

    Lokeshwari Jayaraman

    2016-03-01

    Conclusions: self-perception of not being at risk is documented to be associated with low uptake of screening. Concerned health education programs need to bring clearly to the end user the difference between precancerous lesions and invasive cervical cancer and the treatment options available. [Int J Res Med Sci 2016; 4(3.000: 766-769

  10. Some Melanoma Survivors Still Seek Out the Sun

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_163887.html Some Melanoma Survivors Still Seek Out the Sun 1 in ... Even after surviving the potentially deadly skin cancer melanoma, some people continue to go out in the ...

  11. Microfluidic Radiometal Labeling Systems for Biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Reichert, D E; Kenis, P J. A.

    2011-12-29

    In a typical labeling procedure with radiometals, such as Cu-64 and Ga-68; a very large (~ 100-fold) excess of the non-radioactive reactant (precursor) is used to promote rapid and efficient incorporation of the radioisotope into the PET imaging agent. In order to achieve high specific activities, careful control of reaction conditions and extensive chromatographic purifications are required in order to separate the labeled compounds from the cold precursors. Here we propose a microfluidic approach to overcome these problems, and achieve high specific activities in a more convenient, semi-automated fashion and faster time frame. Microfluidic reactors, consisting of a network of micron-sized channels (typical dimensions in the range 10 - 300¼m), filters, separation columns, electrodes and reaction loops/chambers etched onto a solid substrate, are now emerging as an extremely useful technology for the intensification and miniaturization of chemical processes. The ability to manipulate, process and analyze reagent concentrations and reaction interfaces in both space and time within the channel network of a microreactor provides the fine level of reaction control that is desirable in PET radiochemistry practice. These factors can bring radiometal labeling, specifically the preparation of radio-labeled biomolecules such as antibodies, much closer to their theoretical maximum specific activities.

  12. Formation of biomolecule precursors in space

    Energy Technology Data Exchange (ETDEWEB)

    Geppert, W D [Department of Physics, Stockholm University, Alba Nova, Roslagstullbacken 21, SE-10691, Stockholm (Sweden); Vigren, E [Department of Physics, Stockholm University, Alba Nova, Roslagstullbacken 21, SE-10691, Stockholm (Sweden); Hamberg, M [Department of Physics, Stockholm University, Alba Nova, Roslagstullbacken 21, SE-10691, Stockholm (Sweden); Zhaunerchyk, V [Department of Physics, Stockholm University, Alba Nova, Roslagstullbacken 21, SE-10691, Stockholm (Sweden); Thomas, R D [Department of Physics, Stockholm University, Alba Nova, Roslagstullbacken 21, SE-10691, Stockholm (Sweden); Kaminska, M [Institute of Physics, Swieetokrzyska Academy, ul. Swieokrzyska 15, PL-25406, Kielce (Poland); Millar, T J [Astrophysics Research Centre, Queen' s University Belfast, BT7 1NN, Belfast, Northern Ireland (United Kingdom); Semaniak, J [Institute of Physics, Swieetokrzyska Academy, ul. Swieokrzyska 15, PL-25406, Kielce (Poland); Roberts, H [Astrophysics Research Centre, Queen' s University Belfast, BT7 1NN, Belfast, Northern Ireland (United Kingdom); Hellberg, F [Department of Physics, Stockholm University, Alba Nova, Roslagstullbacken 21, SE-10691, Stockholm (Sweden); Oesterdahl, F [Department of Physics, Royal Institute of Technology, Alba Nova, Roslagstullbacken 21, SE-10691, Stockholm (Sweden); Ehlerding, A [Department of Physics, Stockholm University, Alba Nova, Roslagstullbacken 21, SE-10691, Stockholm (Sweden); Larsson, M [Department of Physics, Stockholm University, Alba Nova, Roslagstullbacken 21, SE-10691, Stockholm (Sweden)

    2007-11-15

    Alcohols and nitriles not only play an important role as templates for synthesis of larger molecules in the interstellar medium and planetary atmospheres, but they can also be regarded as precursors for biomolecules. Alcohols can form carbohydrates through reaction with HCO and nitriles can be hydrolysed to amino acids in aqueous solutions, which is the final step of the well-known Strecker synthesis. Therefore the question of the pathways of formation of alcohols and nitriles and the efficiency and the product distribution of their subsequent degradation reactions in the above-mentioned astrophysical environments is of great interest. In both processes dissociative recombination reactions of protonated nitriles and alcohols may play a major role and are included in models of interstellar clouds and planetary atmospheres. However, the reaction rate coefficients and product branching ratios for the majority of these processes are so far still unknown, which adversely affects the quality of predictions of model calculations. In this Contribution, we therefore present branching ratios and rate constants of the dissociative recombination of protonated methanol (CH{sub 3}OH{sub 2}), as well as protonated acetonitrile (CH{sub 3}CNH{sup +}), acrylonitrile (C{sub 2}H{sub 3}CNH{sup +}) and cyanoacetylene (HC{sup 3}NH{sup +}). The impact of the obtained new data on model calculations of abundances of important interstellar molecules in dark clouds is discussed.

  13. Diffusion phenomena of cells and biomolecules in microfluidic devices.

    Science.gov (United States)

    Yildiz-Ozturk, Ece; Yesil-Celiktas, Ozlem

    2015-09-01

    Biomicrofluidics is an emerging field at the cross roads of microfluidics and life sciences which requires intensive research efforts in terms of introducing appropriate designs, production techniques, and analysis. The ultimate goal is to deliver innovative and cost-effective microfluidic devices to biotech, biomedical, and pharmaceutical industries. Therefore, creating an in-depth understanding of the transport phenomena of cells and biomolecules becomes vital and concurrently poses significant challenges. The present article outlines the recent advancements in diffusion phenomena of cells and biomolecules by highlighting transport principles from an engineering perspective, cell responses in microfluidic devices with emphases on diffusion- and flow-based microfluidic gradient platforms, macroscopic and microscopic approaches for investigating the diffusion phenomena of biomolecules, microfluidic platforms for the delivery of these molecules, as well as the state of the art in biological applications of mammalian cell responses and diffusion of biomolecules.

  14. On the mobility of biomolecules : a fluorescence microscopy approach

    NARCIS (Netherlands)

    Bogaart, Geert van den

    2008-01-01

    This thesis describes the development and application of a number of fluorescence spectroscopy related techniques (FCS, FRAP, DCFBA) to measure diffusion of biomolecules in cells, in membranes and through membrane pores.

  15. Cellular content of biomolecules in sub-seafloor microbial communities

    DEFF Research Database (Denmark)

    Braun, Stefan; Morono, Yuki; Becker, Kevin W.;

    2016-01-01

    Microbial biomolecules, typically from the cell envelope, can provide crucial information about distribution, activity, and adaptations of sub-seafloor microbial communities. However, when cells die these molecules can be preserved in the sediment on timescales that are likely longer than...... the lifetime of their microbial sources. Here we provide for the first time measurements of the cellular content of biomolecules in sedimentary microbial cells. We separated intact cells from sediment matrices in samples from surficial, deeply buried, organic-rich, and organic-lean marine sediments by density...... and mass spectrometry for biomolecule analyses. Because cell extracts from density centrifugation still contained considerable amounts of detrital particles and non-cellular biomolecules, we further purified cells from two samples by fluorescence-activated cell sorting (FACS). Cells from these highly...

  16. Fullerene-biomolecule conjugates and their biomedicinal applications.

    Science.gov (United States)

    Yang, Xinlin; Ebrahimi, Ali; Li, Jie; Cui, Quanjun

    2014-01-01

    Fullerenes are among the strongest antioxidants and are characterized as "radical sponges." The research on biomedicinal applications of fullerenes has achieved significant progress since the landmark publication by Friedman et al in 1993. Fullerene-biomolecule conjugates have become an important area of research during the past 2 decades. By a thorough literature search, we attempt to update the information about the synthesis of different types of fullerene-biomolecule conjugates, including fullerene-containing amino acids and peptides, oligonucleotides, sugars, and esters. Moreover, we also discuss in this review recently reported data on the biological and pharmaceutical utilities of these compounds and some other fullerene derivatives of biomedical importance. While within the fullerene-biomolecule conjugates, in which fullerene may act as both an antioxidant and a carrier, specific targeting biomolecules conjugated to fullerene will undoubtedly strengthen the delivery of functional fullerenes to sites of clinical interest.

  17. Surface manipulation of biomolecules for cell microarray applications.

    Science.gov (United States)

    Hook, Andrew L; Thissen, Helmut; Voelcker, Nicolas H

    2006-10-01

    Many biological events, such as cellular communication, antigen recognition, tissue repair and DNA linear transfer, are intimately associated with biomolecule interactions at the solid-liquid interface. To facilitate the study and use of these biological events for biodevice and biomaterial applications, a sound understanding of how biomolecules behave at interfaces and a concomitant ability to manipulate biomolecules spatially and temporally at surfaces is required. This is particularly true for cell microarray applications, where a range of biological processes must be duly controlled to maximize the efficiency and throughput of these devices. Of particular interest are transfected-cell microarrays (TCMs), which significantly widen the scope of microarray genomic analysis by enabling the high-throughput analysis of gene function within living cells. This article reviews this current research focus, discussing fundamental and applied research into the spatial and temporal surface manipulation of DNA, proteins and other biomolecules and the implications of this work for TCMs.

  18. Information seeking behavior

    DEFF Research Database (Denmark)

    Hjørland, Birger

    2000-01-01

    A general theory of information seeking behaviour must include an outline of an evolutionary theory of how organisms have adapted their cognitive apparatus to the demands raised in order to cope with their environments. It should describe important qualitative stages in this development and expla...

  19. Auctions with rent seeking

    NARCIS (Netherlands)

    Haan, Marco; Schoonbeek, Lambert

    2000-01-01

    We present a model which combines elements of an auction and a rent-seeking contest. Players compete for a prize. Apart from exerting lobbying efforts, they also have to submit a bid which is payable only if they win the prize. First, we analyze the model if the returns-to-scale parameters of both b

  20. Cellular content of biomolecules in sub-seafloor microbial communities

    Science.gov (United States)

    Braun, Stefan; Morono, Yuki; Becker, Kevin W.; Hinrichs, Kai-Uwe; Kjeldsen, Kasper U.; Jørgensen, Bo B.; Lomstein, Bente Aa.

    2016-09-01

    Microbial biomolecules, typically from the cell envelope, can provide crucial information about distribution, activity, and adaptations of sub-seafloor microbial communities. However, when cells die these molecules can be preserved in the sediment on timescales that are likely longer than the lifetime of their microbial sources. Here we provide for the first time measurements of the cellular content of biomolecules in sedimentary microbial cells. We separated intact cells from sediment matrices in samples from surficial, deeply buried, organic-rich, and organic-lean marine sediments by density centrifugation. Amino acids, amino sugars, muramic acid, and intact polar lipids were analyzed in both whole sediment and cell extract, and cell separation was optimized and evaluated in terms of purity, separation efficiency, taxonomic resemblance, and compatibility to high-performance liquid chromatography and mass spectrometry for biomolecule analyses. Because cell extracts from density centrifugation still contained considerable amounts of detrital particles and non-cellular biomolecules, we further purified cells from two samples by fluorescence-activated cell sorting (FACS). Cells from these highly purified cell extracts had an average content of amino acids and lipids of 23-28 fg cell-1 and 2.3 fg cell-1, respectively, with an estimated carbon content of 19-24 fg cell-1. In the sediment, the amount of biomolecules associated with vegetative cells was up to 70-fold lower than the total biomolecule content. We find that the cellular content of biomolecules in the marine subsurface is up to four times lower than previous estimates. Our approach will facilitate and improve the use of biomolecules as proxies for microbial abundance in environmental samples and ultimately provide better global estimates of microbial biomass.

  1. Extracting folding landscape characteristics of biomolecules using mechanical forces

    OpenAIRE

    2015-01-01

    In recent years single molecule force spectroscopy has opened a new avenue to provide profiles of the complex energy landscape of biomolecules. In this field, quantitative analyses of the data employing sound theoretical models, have played a major role in interpreting data and anticipating outcomes of experiments. Here, we explain how by using temperature as a variable in mechanical unfolding of biomolecules in force spectroscopy, the roughness of the energy landscape can be measured without...

  2. On Macroscopic Quantum Phenomena in Biomolecules and Cells: From Levinthal to Hopfield

    Science.gov (United States)

    Raković, Dejan; Dugić, Miroljub; Jeknić-Dugić, Jasmina; Plavšić, Milenko; Jaćimovski, Stevo; Šetrajčić, Jovan

    2014-01-01

    In the context of the macroscopic quantum phenomena of the second kind, we hereby seek for a solution-in-principle of the long standing problem of the polymer folding, which was considered by Levinthal as (semi)classically intractable. To illuminate it, we applied quantum-chemical and quantum decoherence approaches to conformational transitions. Our analyses imply the existence of novel macroscopic quantum biomolecular phenomena, with biomolecular chain folding in an open environment considered as a subtle interplay between energy and conformation eigenstates of this biomolecule, governed by quantum-chemical and quantum decoherence laws. On the other hand, within an open biological cell, a system of all identical (noninteracting and dynamically noncoupled) biomolecular proteins might be considered as corresponding spatial quantum ensemble of these identical biomolecular processors, providing spatially distributed quantum solution to a single corresponding biomolecular chain folding, whose density of conformational states might be represented as Hopfield-like quantum-holographic associative neural network too (providing an equivalent global quantum-informational alternative to standard molecular-biology local biochemical approach in biomolecules and cells and higher hierarchical levels of organism, as well). PMID:25028662

  3. On Macroscopic Quantum Phenomena in Biomolecules and Cells: From Levinthal to Hopfield

    Directory of Open Access Journals (Sweden)

    Dejan Raković

    2014-01-01

    Full Text Available In the context of the macroscopic quantum phenomena of the second kind, we hereby seek for a solution-in-principle of the long standing problem of the polymer folding, which was considered by Levinthal as (semiclassically intractable. To illuminate it, we applied quantum-chemical and quantum decoherence approaches to conformational transitions. Our analyses imply the existence of novel macroscopic quantum biomolecular phenomena, with biomolecular chain folding in an open environment considered as a subtle interplay between energy and conformation eigenstates of this biomolecule, governed by quantum-chemical and quantum decoherence laws. On the other hand, within an open biological cell, a system of all identical (noninteracting and dynamically noncoupled biomolecular proteins might be considered as corresponding spatial quantum ensemble of these identical biomolecular processors, providing spatially distributed quantum solution to a single corresponding biomolecular chain folding, whose density of conformational states might be represented as Hopfield-like quantum-holographic associative neural network too (providing an equivalent global quantum-informational alternative to standard molecular-biology local biochemical approach in biomolecules and cells and higher hierarchical levels of organism, as well.

  4. Miniature Laboratory for Detecting Sparse Biomolecules

    Science.gov (United States)

    Lin, Ying; Yu, Nan

    2005-01-01

    A miniature laboratory system has been proposed for use in the field to detect sparsely distributed biomolecules. By emphasizing concentration and sorting of specimens prior to detection, the underlying system concept would make it possible to attain high detection sensitivities without the need to develop ever more sensitive biosensors. The original purpose of the proposal is to aid the search for signs of life on a remote planet by enabling the detection of specimens as sparse as a few molecules or microbes in a large amount of soil, dust, rocks, water/ice, or other raw sample material. Some version of the system could prove useful on Earth for remote sensing of biological contamination, including agents of biological warfare. Processing in this system would begin with dissolution of the raw sample material in a sample-separation vessel. The solution in the vessel would contain floating microscopic magnetic beads coated with substances that could engage in chemical reactions with various target functional groups that are parts of target molecules. The chemical reactions would cause the targeted molecules to be captured on the surfaces of the beads. By use of a controlled magnetic field, the beads would be concentrated in a specified location in the vessel. Once the beads were thus concentrated, the rest of the solution would be discarded. This procedure would obviate the filtration steps and thereby also eliminate the filter-clogging difficulties of typical prior sample-concentration schemes. For ferrous dust/soil samples, the dissolution would be done first in a separate vessel before the solution is transferred to the microbead-containing vessel.

  5. Multi-state modeling of biomolecules.

    Directory of Open Access Journals (Sweden)

    Melanie I Stefan

    2014-09-01

    Full Text Available Multi-state modeling of biomolecules refers to a series of techniques used to represent and compute the behavior of biological molecules or complexes that can adopt a large number of possible functional states. Biological signaling systems often rely on complexes of biological macromolecules that can undergo several functionally significant modifications that are mutually compatible. Thus, they can exist in a very large number of functionally different states. Modeling such multi-state systems poses two problems: the problem of how to describe and specify a multi-state system (the "specification problem" and the problem of how to use a computer to simulate the progress of the system over time (the "computation problem". To address the specification problem, modelers have in recent years moved away from explicit specification of all possible states and towards rule-based formalisms that allow for implicit model specification, including the κ-calculus, BioNetGen, the Allosteric Network Compiler, and others. To tackle the computation problem, they have turned to particle-based methods that have in many cases proved more computationally efficient than population-based methods based on ordinary differential equations, partial differential equations, or the Gillespie stochastic simulation algorithm. Given current computing technology, particle-based methods are sometimes the only possible option. Particle-based simulators fall into two further categories: nonspatial simulators, such as StochSim, DYNSTOC, RuleMonkey, and the Network-Free Stochastic Simulator (NFSim, and spatial simulators, including Meredys, SRSim, and MCell. Modelers can thus choose from a variety of tools, the best choice depending on the particular problem. Development of faster and more powerful methods is ongoing, promising the ability to simulate ever more complex signaling processes in the future.

  6. Decisions to use complementary and alternative medicine (CAM by male cancer patients: information-seeking roles and types of evidence used

    Directory of Open Access Journals (Sweden)

    Thompson Trevor

    2007-08-01

    Full Text Available Abstract Background Complementary and Alternative Medicine (CAM is increasingly popular with cancer patients and yet information provision or discussion about CAM by health professionals remains low. Previous research suggests that patients may fear clinicians' 'disapproval' if they raise the subject of CAM, and turn to other sources to acquire information about CAM. However, little empirical research has been conducted into how cancer patients acquire, and, more importantly evaluate CAM information before deciding which CAM therapies to try. Methods Qualitative study, comprising semi-structured interviews with 43 male cancer patients of varying ages, cancer type and stage of illness, 34 of whom had used CAM. They were recruited from a range of NHS and non-NHS settings in Bristol, England. Results As a result of the lack of CAM information from health professionals, men in this study became either 'pro-active seekers' or 'passive recipients' of such information. Their main information resource was the 'lay referral' network of family, friends and acquaintances, especially females. 'Traditional' information sources, including books, magazines, leaflets and the media were popular, more so in fact than the internet. Views on the internet ranged from enthusiasm or healthy scepticism through to caution or disinterest. CAM information was generally regarded as 'empowering' as it broadened treatment and self-care options. A minority of participants were information averse fearing additional choices that might disrupt their fragile ability to cope. There was general consensus that CAM information should be available via the NHS, to give it a 'stamp of approval', which combined with guidance from informed health professionals, could help patients to make 'guided' choices. However, a small minority of these men valued the independence of CAM from the NHS and deliberately sought 'alternative' information sources and treatment options. Men were selective in

  7. Tools and procedures for visualization of proteins and other biomolecules.

    Science.gov (United States)

    Pan, Lurong; Aller, Stephen G

    2015-04-01

    Protein, peptides, and nucleic acids are biomolecules that drive biological processes in living organisms. An enormous amount of structural data for a large number of these biomolecules has been described with atomic precision in the form of structural "snapshots" that are freely available in public repositories. These snapshots can help explain how the biomolecules function, the nature of interactions between multi-molecular complexes, and even how small-molecule drugs can modulate the biomolecules for clinical benefits. Furthermore, these structural snapshots serve as inputs for sophisticated computer simulations to turn the biomolecules into moving, "breathing" molecular machines for understanding their dynamic properties in real-time computer simulations. In order for the researcher to take advantage of such a wealth of structural data, it is necessary to gain competency in the use of computer molecular visualization tools for exploring the structures and visualizing three-dimensional spatial representations. Here, we present protocols for using two common visualization tools--the Web-based Jmol and the stand-alone PyMOL package--as well as a few examples of other popular tools.

  8. Temperature-responsive chromatography for the separation of biomolecules.

    Science.gov (United States)

    Kanazawa, Hideko; Okano, Teruo

    2011-12-09

    Temperature-responsive chromatography for the separation of biomolecules utilizing poly(N-isopropylacrylamide) (PNIPAAm) and its copolymer-modified stationary phase is performed with an aqueous mobile phase without using organic solvent. The surface properties and function of the stationary phase are controlled by external temperature changes without changing the mobile-phase composition. This analytical system is based on nonspecific adsorption by the reversible transition of a hydrophilic-hydrophobic PNIPAAm-grafted surface. The driving force for retention is hydrophobic interaction between the solute molecules and the hydrophobized polymer chains on the stationary phase surface. The separation of the biomolecules, such as nucleotides and proteins was achieved by a dual temperature- and pH-responsive chromatography system. The electrostatic and hydrophobic interactions could be modulated simultaneously with the temperature in an aqueous mobile phase, thus the separation system would have potential applications in the separation of biomolecules. Additionally, chromatographic matrices prepared by a surface-initiated atom transfer radical polymerization (ATRP) exhibit a strong interaction with analytes, because the polymerization procedure forms a densely packed polymer, called a polymer brush, on the surfaces. The copolymer brush grafted surfaces prepared by ATRP was an effective tool for separating basic biomolecules by modulating the electrostatic and hydrophobic interactions. Applications of thermally responsive columns for the separations of biomolecules are reviewed here.

  9. International students’ information seeking behavior

    DEFF Research Database (Denmark)

    Hyldegård, Jette Seiden

    2016-01-01

    associated with information seeking abroad five themes were identified for further examination and analysis: 1) the international student identity; 2) the influence from individual characteristics and experiences; 3) private and academic information seeking during time; 4) language barriers across private...

  10. Constraint methods that accelerate free-energy simulations of biomolecules.

    Science.gov (United States)

    Perez, Alberto; MacCallum, Justin L; Coutsias, Evangelos A; Dill, Ken A

    2015-12-28

    Atomistic molecular dynamics simulations of biomolecules are critical for generating narratives about biological mechanisms. The power of atomistic simulations is that these are physics-based methods that satisfy Boltzmann's law, so they can be used to compute populations, dynamics, and mechanisms. But physical simulations are computationally intensive and do not scale well to the sizes of many important biomolecules. One way to speed up physical simulations is by coarse-graining the potential function. Another way is to harness structural knowledge, often by imposing spring-like restraints. But harnessing external knowledge in physical simulations is problematic because knowledge, data, or hunches have errors, noise, and combinatoric uncertainties. Here, we review recent principled methods for imposing restraints to speed up physics-based molecular simulations that promise to scale to larger biomolecules and motions.

  11. Constraint methods that accelerate free-energy simulations of biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Alberto [Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York 11794 (United States); MacCallum, Justin L. [Department of Chemistry, University of Calgary, Calgary, Alberta T2N 1N4 (Canada); Coutsias, Evangelos A. [Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York 11794 (United States); Department of Applied Mathematics, Stony Brook University, Stony Brook, New York 11794 (United States); Dill, Ken A. [Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York 11794 (United States); Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794 (United States)

    2015-12-28

    Atomistic molecular dynamics simulations of biomolecules are critical for generating narratives about biological mechanisms. The power of atomistic simulations is that these are physics-based methods that satisfy Boltzmann’s law, so they can be used to compute populations, dynamics, and mechanisms. But physical simulations are computationally intensive and do not scale well to the sizes of many important biomolecules. One way to speed up physical simulations is by coarse-graining the potential function. Another way is to harness structural knowledge, often by imposing spring-like restraints. But harnessing external knowledge in physical simulations is problematic because knowledge, data, or hunches have errors, noise, and combinatoric uncertainties. Here, we review recent principled methods for imposing restraints to speed up physics-based molecular simulations that promise to scale to larger biomolecules and motions.

  12. Kinetic analysis of interaction between lipopolysaccharide and biomolecules

    Institute of Scientific and Technical Information of China (English)

    Fan YANG; Xiurong YANG

    2008-01-01

    Lipopolysaccharide (LPS) is a major compo-nent of the outer membrane of all gram-negative bacteria. It interacts with some biomolecules and triggers a toxic reaction. In this paper, we studied the interaction between LPS from Salmonella Minnesota and some biomolecules using a surface plasmon resonance (SPR) biosensor. Biomolecules were immobilized on a CM5 sensor chip using the amino coupling method and LPS was injected over the immobilized surfaces. The affinity constant KA of LPS with serum albumin, hemoglobin, chitosan and lysozyme was 2.36 × 107, 2.03 × 108,7.58×106, 2.82 × 104 L·mol-1, respectively. However, LPS could not interact with ferritin.

  13. Printing technologies for biomolecule and cell-based applications.

    Science.gov (United States)

    Ihalainen, Petri; Määttänen, Anni; Sandler, Niklas

    2015-10-30

    Biomolecules, such as enzymes, proteins and other biomacromolecules (polynucleotides, polypeptides, polysaccharides and DNA) that are immobilized on solid surfaces are relevant to many areas of science and technology. These functionalized surfaces have applications in biosensors, chromatography, diagnostic immunoassays, cell culturing, DNA microarrays and other analytical techniques. Printing technologies offer opportunities in this context. The main interests in printing biomolecules are in immobilizing them on surfaces for sensors and catalysts or for controlled delivery of protein-based drugs. Recently, there have been significant developments in the use of inkjet printing for dispensing of proteins, biomacromolecules and cells. This review discusses the use of roll-to-roll and inkjet printing technologies in manufacturing of biomolecule and cell-based applications.

  14. Understanding small biomolecule-biomaterial interactions: a review of fundamental theoretical and experimental approaches for biomolecule interactions with inorganic surfaces.

    Science.gov (United States)

    Costa, Dominique; Garrain, Pierre-Alain; Baaden, Marc

    2013-04-01

    Interactions between biomolecules and inorganic surfaces play an important role in natural environments and in industry, including a wide variety of conditions: marine environment, ship hulls (fouling), water treatment, heat exchange, membrane separation, soils, mineral particles at the earth's surface, hospitals (hygiene), art and buildings (degradation and biocorrosion), paper industry (fouling) and more. To better control the first steps leading to adsorption of a biomolecule on an inorganic surface, it is mandatory to understand the adsorption mechanisms of biomolecules of several sizes at the atomic scale, that is, the nature of the chemical interaction between the biomolecule and the surface and the resulting biomolecule conformations once adsorbed at the surface. This remains a challenging and unsolved problem. Here, we review the state of art in experimental and theoretical approaches. We focus on metallic biomaterial surfaces such as TiO(2) and stainless steel, mentioning some remarkable results on hydroxyapatite. Experimental techniques include atomic force microscopy, surface plasmon resonance, quartz crystal microbalance, X-ray photoelectron spectroscopy, fluorescence microscopy, polarization modulation infrared reflection absorption spectroscopy, sum frequency generation and time of flight secondary ion mass spectroscopy. Theoretical models range from detailed quantum mechanical representations to classical forcefield-based approaches.

  15. Knowledge, attitude and practice about breast cancer and breast self-examination among women seeking out-patient care in a teaching hospital in central India

    Directory of Open Access Journals (Sweden)

    Rao Siddharth

    2016-01-01

    Full Text Available Background: Breast cancer (BC continues to be a major cause of morbidity and mortality throughout the world. Early detection of BC and early treatment increases the chance of survival. According to Breast Health Global Initiative guidelines for low and middle income countries, diagnosing BCs early by promoting breast self-awareness; clinical breast examination (CBE and resource adapted mammographic screening will reduce BC mortality. There is a paucity of data on the knowledge and awareness of BC and self-breast examination in India. We designed this hospital based cross sectional descriptive study to evaluate the current status of knowledge, awareness and practices related to BC and breast self-examination in the female rural population attending a teaching hospital. Materials and Methods: We did a random sampling to identify and enroll 360 women and their female relatives. We excluded a participant from the study if she had already undergone a screening mammography or had had a BC. The data was collected by a self-administered questionnaire in vernacular language. Results: Our study population included 360 women with a mean age of 45.81 (±10.9 years. Only 5 (1.38% females had a family history of BC. A whopping 81% of women did not have any knowledge about BC. All the women thought that CBE by doctors was the only way for screening BC. Conclusions: We concluded that with the results of this study, it is imperative to increase awareness about BC and its detection methods in the community through health education campaigns. We should have major policy changes to increase future screening programs and health education programs which would have an overall positive impact on reducing the disease burden.

  16. Quantum chemistry and charge transport in biomolecules with superconducting circuits

    Science.gov (United States)

    García-Álvarez, L.; Las Heras, U.; Mezzacapo, A.; Sanz, M.; Solano, E.; Lamata, L.

    2016-06-01

    We propose an efficient protocol for digital quantum simulation of quantum chemistry problems and enhanced digital-analog quantum simulation of transport phenomena in biomolecules with superconducting circuits. Along these lines, we optimally digitize fermionic models of molecular structure with single-qubit and two-qubit gates, by means of Trotter-Suzuki decomposition and Jordan-Wigner transformation. Furthermore, we address the modelling of system-environment interactions of biomolecules involving bosonic degrees of freedom with a digital-analog approach. Finally, we consider gate-truncated quantum algorithms to allow the study of environmental effects.

  17. Supramolecular Assemblies Responsive to Biomolecules toward Biological Applications.

    Science.gov (United States)

    Shigemitsu, Hajime; Hamachi, Itaru

    2015-10-01

    Stimuli-responsive supramolecular assemblies consisting of small molecules are attractive functional materials for biological applications such as drug delivery, medical diagnosis, enzyme immobilization, and tissue engineering. By use of their dynamic and reversible properties, many supramolecular assemblies responsive to a variety of biomolecules have been designed and synthesized. This review focuses on promising strategies for the construction of such dynamic supramolecular assemblies and their functions. While studies of biomolecule-responsive supramolecular assemblies have mainly been performed in vitro, it has recently been demonstrated that some of them can work in live cells. Supramolecular assemblies now open up new avenues in chemical biology and biofunctional materials.

  18. Quantum chemistry and charge transport in biomolecules with superconducting circuits.

    Science.gov (United States)

    García-Álvarez, L; Las Heras, U; Mezzacapo, A; Sanz, M; Solano, E; Lamata, L

    2016-06-21

    We propose an efficient protocol for digital quantum simulation of quantum chemistry problems and enhanced digital-analog quantum simulation of transport phenomena in biomolecules with superconducting circuits. Along these lines, we optimally digitize fermionic models of molecular structure with single-qubit and two-qubit gates, by means of Trotter-Suzuki decomposition and Jordan-Wigner transformation. Furthermore, we address the modelling of system-environment interactions of biomolecules involving bosonic degrees of freedom with a digital-analog approach. Finally, we consider gate-truncated quantum algorithms to allow the study of environmental effects.

  19. Quantum chemistry and charge transport in biomolecules with superconducting circuits

    Science.gov (United States)

    García-Álvarez, L.; Las Heras, U.; Mezzacapo, A.; Sanz, M.; Solano, E.; Lamata, L.

    2016-01-01

    We propose an efficient protocol for digital quantum simulation of quantum chemistry problems and enhanced digital-analog quantum simulation of transport phenomena in biomolecules with superconducting circuits. Along these lines, we optimally digitize fermionic models of molecular structure with single-qubit and two-qubit gates, by means of Trotter-Suzuki decomposition and Jordan-Wigner transformation. Furthermore, we address the modelling of system-environment interactions of biomolecules involving bosonic degrees of freedom with a digital-analog approach. Finally, we consider gate-truncated quantum algorithms to allow the study of environmental effects. PMID:27324814

  20. Sensation Seeking in Street Violence

    DEFF Research Database (Denmark)

    Heinskou, Marie Bruvik; Liebst, Lasse Suonperä

    Sensation seeking leads to violence—runs an influential hypothesis in the social scientific study of violent behavior. Although studies confirm that violence is sometimes structured by sensation-seeking motives, the literature seldom comments on the limits to this explanation of violence...... involving street violence, which are coded quantitatively and qualitatively. Our analysis shows that sensation seeking only seldom seems to play a role in the structuring of street violence. Moreover, the data indicate that sensation seeking finds expression in street violence situations in two different....... The present study examines the scale of violence motivated by sensation seeking and the degree to which there are several distinct forms of sensation seeking motives operative in violence, rather than a sensation-seeking motive in the singular. The study draws on a sample of situations from Copenhagen...

  1. Online health information seeking

    DEFF Research Database (Denmark)

    Synnot, Anneliese J.; Hill, Sophie J.; Garner, Kerryn A.

    2016-01-01

    Background and objective: The Internet is increasingly prominent as a source of health information for people with multiple sclerosis (MS). But there has been little exploration of the needs, experiences and preferences of people with MS for integrating treatment information into decision making......-regulation' to capture the variations in information seeking behaviour that participants described over time, as they responded to their changing information needs, their emotional state and growing expertise about MS. Conclusions: People with MS have developed a number of strategies to both find and integrate treatment......, in the context of searching on the Internet. This was the aim of our study. Design: Sixty participants (51 people with MS; nine family members) took part in a focus group or online forum. They were asked to describe how they find and assess reliable treatment information (particularly online) and how...

  2. Sexual minorities seeking services.

    Science.gov (United States)

    Rogers, Tracey L; Emanuel, Kristen; Bradford, Judith

    2003-01-01

    SUMMARY Understanding the mental health needs of lesbian and bisexual (sexual minority) women is an integral part of designing and providing appropriate mental health services and treatment for them. In an effort to understand the mental health needs of sexual minority women who seek community treatment, a chart review was conducted of the 223 lesbian and bisexual women who presented for services between July 1, 1997 and December 31, 2000 at Fenway Community Health in Boston, MA. Data are based on clients' self-reports and clinician assessments of clients' presenting problem, relevant developmental history, prior mental health and substance abuse treatment, current reports of emotional/psychological symptoms, and areas of impaired functioning. Although substance abuse and suicidal ideation were commonly reported problems, other concerns were more frequently reported. High percentages of lesbians and bisexual women reported relationship concerns and lack of adequate social networks; rates of depression and anxiety based on clinicians' assessments were also high. Overall, lesbians and bisexual women did not differ in the issues they brought to treatment or level or types of impairment. Compared with previous community survey samples, however, study participants appeared to be healthier than general, non-clinical samples of self-identified lesbians, possibly reflecting the special characteristics of sexual minority women who seek treatment in specialized community sites such as the Fenway. Although patients who come to these sites may not represent the more general population of sexual minority women, community health centers known to serve lesbian, gay, bisexual and transgender (LGBT) individuals may be fruitful access points for studying the mental health status and treatment needs of sexual minority women.

  3. Recovery of Biomolecules from Food Wastes — A Review

    Directory of Open Access Journals (Sweden)

    Antonietta Baiano

    2014-09-01

    Full Text Available Food wastes are produced by a variety of sources, ranging from agricultural operations to household consumption. About 38% occurs during food processing. At present, the European Union legislation encourages the exploitation of co-products. This valorisation can be achieved through the extraction of high-value components such as proteins, polysaccharides, fibres, flavour compounds, and phytochemicals, which can be re-used as nutritionally and pharmacologically functional ingredients. Extraction can proceed according to solid-liquid extraction, Soxhlet extraction, pressurized fluid extraction, supercritical fluid extraction, ultrasound-assisted extraction, microwave-assisted extraction, pulsed electric field extraction, and enzyme-assisted extraction. Nevertheless, these techniques cannot be used indiscriminately and their choice depends on the type of biomolecules and matrix, the scale processing (laboratory or industrial, the ratio between production costs and economic values of the compounds to be extracted. The vegetable wastes include trimmings, peelings, stems, seeds, shells, bran, residues remaining after extraction of oil, starch, sugar, and juice. The animal-derived wastes include wastes from bred animals, wastes from seafood, wastes from dairy processing. The recovered biomolecules and by-products can be used to produce functional foods or as adjuvants in food processing or in medicinal and pharmaceutical preparations. This work is an overview of the type and amounts of food wastes; food waste legislation; conventional and novel techniques suitable for extracting biomolecules; food, medicinal and pharmaceutical uses of the recovered biomolecules and by-products, and future trends in these areas.

  4. Recovery of biomolecules from food wastes--a review.

    Science.gov (United States)

    Baiano, Antonietta

    2014-09-17

    Food wastes are produced by a variety of sources, ranging from agricultural operations to household consumption. About 38% occurs during food processing. At present, the European Union legislation encourages the exploitation of co-products. This valorisation can be achieved through the extraction of high-value components such as proteins, polysaccharides, fibres, flavour compounds, and phytochemicals, which can be re-used as nutritionally and pharmacologically functional ingredients. Extraction can proceed according to solid-liquid extraction, Soxhlet extraction, pressurized fluid extraction, supercritical fluid extraction, ultrasound-assisted extraction, microwave-assisted extraction, pulsed electric field extraction, and enzyme-assisted extraction. Nevertheless, these techniques cannot be used indiscriminately and their choice depends on the type of biomolecules and matrix, the scale processing (laboratory or industrial), the ratio between production costs and economic values of the compounds to be extracted. The vegetable wastes include trimmings, peelings, stems, seeds, shells, bran, residues remaining after extraction of oil, starch, sugar, and juice. The animal-derived wastes include wastes from bred animals, wastes from seafood, wastes from dairy processing. The recovered biomolecules and by-products can be used to produce functional foods or as adjuvants in food processing or in medicinal and pharmaceutical preparations. This work is an overview of the type and amounts of food wastes; food waste legislation; conventional and novel techniques suitable for extracting biomolecules; food, medicinal and pharmaceutical uses of the recovered biomolecules and by-products, and future trends in these areas.

  5. Optical aptasensors for quantitative detection of small biomolecules: a review.

    Science.gov (United States)

    Feng, Chunjing; Dai, Shuang; Wang, Lei

    2014-09-15

    Aptasensors are aptamer-based biosensors with excellent recognition capability towards a wide range of targets. Specially, there have been ever-growing interests in the development of aptasensors for the detection of small molecules. This phenomenon is contributed to two reasons. On one hand, small biomolecules play an important role in living organisms with many kinds of biological function, such as antiarrhythmic effect and vasodilator activity of adenosine. On the other hand, the concentration of small molecules can be an indicator for disease diagnosis, for example, the concentration of ATP is closely associated with cell injury and cell viability. As a potential analysis tool in the construction of aptasensors, optical analysis has attracted much more interest of researchers due to its high sensitivity, quick response and simple operation. Besides, it promises the promotion of aptasensors in performance toward a new level. Review the development of optical aptasensors for small biomolecules will give readers an overall understanding of its progress and provide some theoretical guidelines for its future development. Hence, we give a mini-review on the advance of optical aptasensors for small biomolecules. This review focuses on recent achievements in the design of various optical aptasensors for small biomolecules, containing fluorescence aptasensors, colorimetric aptasensors, chemiluminescence aptasensors and other optical aptasensors.

  6. Silica biomineralization via the self-assembly of helical biomolecules.

    Science.gov (United States)

    Liu, Ben; Cao, Yuanyuan; Huang, Zhehao; Duan, Yingying; Che, Shunai

    2015-01-21

    The biomimetic synthesis of relevant silica materials using biological macromolecules as templates via silica biomineralization processes attract rapidly rising attention toward natural and artificial materials. Biomimetic synthesis studies are useful for improving the understanding of the formation mechanism of the hierarchical structures found in living organisms (such as diatoms and sponges) and for promoting significant developments in the biotechnology, nanotechnology and materials chemistry fields. Chirality is a ubiquitous phenomenon in nature and is an inherent feature of biomolecular components in organisms. Helical biomolecules, one of the most important types of chiral macromolecules, can self-assemble into multiple liquid-crystal structures and be used as biotemplates for silica biomineralization, which renders them particularly useful for fabricating complex silica materials under ambient conditions. Over the past two decades, many new silica materials with hierarchical structures and complex morphologies have been created using helical biomolecules. In this review, the developments in this field are described and the recent progress in silica biomineralization templating using several classes of helical biomolecules, including DNA, polypeptides, cellulose and rod-like viruses is summarized. Particular focus is placed on the formation mechanism of biomolecule-silica materials (BSMs) with hierarchical structures. Finally, current research challenges and future developments are discussed in the conclusion.

  7. Charged porous membrane structures for separation of biomolecules

    NARCIS (Netherlands)

    Kopec, Karina Katarzyna

    2011-01-01

    Thesis presents various membrane techniques for biomolecules separation. New charged membranes and new methods to introduce charge into the membranes are demonstrated. All chapters present characterization of the hollow fiber membranes produced via the immersion precipitation dry-wet spinning. Apart

  8. Artificial tongue based on metal-biomolecule coordination polymer nanoparticles.

    Science.gov (United States)

    Pu, Fang; Ran, Xiang; Ren, Jinsong; Qu, Xiaogang

    2016-02-25

    We construct an array-based recognition system (the so-called artificial tongue) through the self-assembly of nucleotides, dyes and lanthanide ions. Metal ions are selected as model analytes for verifying its discrimination ability. The work provides valuable insights into the application and development of biomolecule-based materials.

  9. Photochemical Microscale Electrophoresis Allows Fast Quantification of Biomolecule Binding.

    Science.gov (United States)

    Möller, Friederike M; Kieß, Michael; Braun, Dieter

    2016-04-27

    Intricate spatiotemporal patterns emerge when chemical reactions couple to physical transport. We induce electrophoretic transport by a confined photochemical reaction and use it to infer the binding strength of a second, biomolecular binding reaction under physiological conditions. To this end, we use the photoactive compound 2-nitrobenzaldehyde, which releases a proton upon 375 nm irradiation. The charged photoproducts locally perturb electroneutrality due to differential diffusion, giving rise to an electric potential Φ in the 100 μV range on the micrometer scale. Electrophoresis of biomolecules in this field is counterbalanced by back-diffusion within seconds. The biomolecule concentration is measured by fluorescence and settles proportionally to exp(-μ/D Φ). Typically, binding alters either the diffusion coefficient D or the electrophoretic mobility μ. Hence, the local biomolecule fluorescence directly reflects the binding state. A fit to the law of mass action reveals the dissociation constant of the binding reaction. We apply this approach to quantify the binding of the aptamer TBA15 to its protein target human-α-thrombin and to probe the hybridization of DNA. Dissociation constants in the nanomolar regime were determined and match both results in literature and in control experiments using microscale thermophoresis. As our approach is all-optical, isothermal and requires only nanoliter volumes at nanomolar concentrations, it will allow for the fast screening of biomolecule binding in low volume multiwell formats.

  10. Fundamentals of Biomolecule Analysis by Electrospray Ionization Mass Spectrometry

    Science.gov (United States)

    Weinecke, Andrea; Ryzhov, Victor

    2005-01-01

    Electrospray ionization (ESI) is a soft ionization technique that allows transfer of fragile biomolecules directly from solution into the gas phase. An instrumental analysis laboratory experiment is designed that would introduce the students to the ESI technique, major parameters of the ion trap mass spectrometers and some caveats in…

  11. Nanofluidic technology for biomolecule applications: a critical review.

    Science.gov (United States)

    Napoli, M; Eijkel, J C T; Pennathur, S

    2010-04-21

    In this review, we present nanofluidic phenomena, particularly as they relate to applications involving analysis of biomolecules within nanofabricated devices. The relevant length scales and physical phenomena that govern biomolecule transport and manipulation within nanofabricated nanofluidic devices are reviewed, the advantages of nanofabricated devices are presented, and relevant applications are cited. Characteristic length scales include the Debye length, the Van der Waals radius, the action distance of hydrogen bonding, the slip length, and macromolecular dimensions. On the basis of the characteristic lengths and related nanofluidic phenomena, a nanofluidic toolbox will be assembled. Nanofluidic phenomena that affect biomolecule behavior within such devices can include ion depletion and enrichment, modified velocity and mobility, permselectivity, steric hindrance, entropy, adsorption, and hydrodynamic interaction. The complex interactions and coupled physics of such phenomena allow for many applications, including biomolecule separation, concentration, reaction/hybridization, sequencing (in the case of DNA) and detection. Examples of devices for such applications will be presented, followed by a discussion of near-term challenges and future thoughts for the field.

  12. Fullerene–biomolecule conjugates and their biomedicinal applications

    Directory of Open Access Journals (Sweden)

    Yang X

    2013-12-01

    Full Text Available Xinlin Yang,1 Ali Ebrahimi,1 Jie Li,1,2 Quanjun Cui11Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Virginia School of Medicine, Charlottesville, VA, USA; 2School of Materials Science, Beijing Institute of Technology, Beijing, People's Republic of ChinaAbstract: Fullerenes are among the strongest antioxidants and are characterized as "radical sponges." The research on biomedicinal applications of fullerenes has achieved significant progress since the landmark publication by Friedman et al in 1993. Fullerene–biomolecule conjugates have become an important area of research during the past 2 decades. By a thorough literature search, we attempt to update the information about the synthesis of different types of fullerene–biomolecule conjugates, including fullerene-containing amino acids and peptides, oligonucleotides, sugars, and esters. Moreover, we also discuss in this review recently reported data on the biological and pharmaceutical utilities of these compounds and some other fullerene derivatives of biomedical importance. While within the fullerene–biomolecule conjugates, in which fullerene may act as both an antioxidant and a carrier, specific targeting biomolecules conjugated to fullerene will undoubtedly strengthen the delivery of functional fullerenes to sites of clinical interest.Keywords: fullerene, amino acid, peptide, oligonucleotide, sugar, ester

  13. Care seeking for orofacial pain

    NARCIS (Netherlands)

    Rollman, A.; Visscher, C.M.; Gorter, R.C.; Naeije, M.

    2012-01-01

    AIMS: To determine the contribution of a wide range of factors to care-seeking behavior in orofacial pain patients, expressed as (A) decision to seek care and (B) number of health care practitioners visited. METHODS: Subjects with orofacial pain complaints were recruited in seven TMD clinics and fro

  14. Breakdowns in collaborative information seeking

    DEFF Research Database (Denmark)

    Hertzum, Morten

    2010-01-01

    of the use of the electronic medication record adopted in a Danish healthcare region and of the reports of five years of medication incidents at Danish hospitals. The results show that breakdowns in collaborative information seeking is a major source of medication incidents, that most of these breakdowns......Collaborative information seeking is integral to many professional activities. In hospital work, the medication process encompasses continual seeking for information and collaborative grounding of information. This study investigates breakdowns in collaborative information seeking through analyses...... are breakdowns in collaborative grounding rather than information seeking, that the medication incidents mainly concern breakdowns in the use of records as opposed to oral communication, that the breakdowns span multiple degrees of separation between clinicians, and that the electronic medication record has...

  15. An overview: biomolecules from microalgae for animal feed and aquaculture.

    Science.gov (United States)

    Yaakob, Zahira; Ali, Ehsan; Zainal, Afifi; Mohamad, Masita; Takriff, Mohd Sobri

    2014-12-01

    Despite being more popular for biofuel, microalgae have gained a lot of attention as a source of biomolecules and biomass for feed purposes. Algae farming can be established using land as well as sea and strategies can be designed in order to gain the products of specific interest in the optimal way. A general overview of the contributions of Algae to meet the requirements of nutrients in animal/aquaculture feed is presented in this study. In addition to its applications in animal/aquaculture feed, algae can produce a number of biomolecules including astaxanthin, lutein, beta-carotene, chlorophyll, phycobiliprotein, Polyunsaturated Fatty Acids (PUFAs), beta-1,3-glucan, and pharmaceutical and nutraceutical compounds which have been reviewed with respect to their commercial importance and current status. The review is further extended to highlight the adequate utilization of value added products in the feeds for livestock, poultry and aquaculture (with emphasis in shrimp farming).

  16. Interactions between cationic liposomes and drugs or biomolecules

    Directory of Open Access Journals (Sweden)

    ANA MARIA CARMONA-RIBEIRO

    2000-03-01

    Full Text Available Multiple uses for synthetic cationic liposomes composed of dioctadecyldimethylammonium bromide (DODAB bilayer vesicles are presented. Drugs or biomolecules can be solubilized or incorporated in the cationic bilayers. The cationic liposomes themselves can act as antimicrobial agents causing death of bacteria and fungi at concentrations that barely affect mammalian cells in culture. Silica particles or polystyrene microspheres can be functionalized by coverage with DODAB bilayers or phospholipid monolayers. Negatively charged antigenic proteins can be carried by the cationic liposomes which generate a remarkable immunoadjuvant action. Nucleotides or DNA can be physically adsorbed to the cationic liposomes to be transferred to mammalian cells for gene therapy. An overview of the interactions between DODAB vesicles and some biomolecules or drugs clearly points out their versatility for useful applications in a near future.

  17. Interactions between cationic liposomes and drugs or biomolecules.

    Science.gov (United States)

    Carmona-Ribeiro, A M

    2000-01-01

    Multiple uses for synthetic cationic liposomes composed of dioctadecyldimethylammonium bromide (DODAB) bilayer vesicles are presented. Drugs or biomolecules can be solubilized or incorporated in the cationic bilayers. The cationic liposomes themselves can act as antimicrobial agents causing death of bacteria and fungi at concentrations that barely affect mammalian cells in culture. Silica particles or polystyrene microspheres can be functionalized by coverage with DODAB bilayers or phospholipid monolayers. Negatively charged antigenic proteins can be carried by the cationic liposomes which generate a remarkable immunoadjuvant action. Nucleotides or DNA can be physically adsorbed to the cationic liposomes to be transferred to mammalian cells for gene therapy. An overview of the interactions between DODAB vesicles and some biomolecules or drugs clearly points out their versatility for useful applications in a near future.

  18. Biomolecule-nanoparticle hybrids as functional units for nanobiotechnology.

    Science.gov (United States)

    Baron, Ronan; Willner, Bilha; Willner, Itamar

    2007-01-28

    Biomolecule-metal or semiconductor nanoparticle (NP) hybrid systems combine the recognition and catalytic properties of biomolecules with the unique electronic and optical properties of NPs. This enables the application of the hybrid systems in developing new electronic and optical biosensors, to synthesize nanowires and nanocircuits, and to fabricate new devices. Metal NPs are employed as nano-connectors that activate redox enzymes, and they act as electrical or optical labels for biorecognition events. Similarly, semiconductor NPs act as optical probes for biorecognition processes. Double-stranded DNA or protein chains that are modified with metallic nanoclusters act as templates for the synthesis of metallic nanowires. The nanowires are used as building blocks to assemble nano-devices such as a transistor or a nanotransporter.

  19. Surface Treatment of Polymeric Materials Controlling the Adhesion of Biomolecules

    Directory of Open Access Journals (Sweden)

    Willy Zorzi

    2012-08-01

    Full Text Available This review describes different strategies of surface elaboration for a better control of biomolecule adsorption. After a brief description of the fundamental interactions between surfaces and biomolecules, various routes of surface elaboration are presented dealing with the attachment of functional groups mostly thanks to plasma techniques, with the grafting to and from methods, and with the adsorption of surfactants. The grafting of stimuli-responsive polymers is also pointed out. Then, the discussion is focused on the protein adsorption phenomena showing how their interactions with solid surfaces are complex. The adsorption mechanism is proved to be dependent on the solid surface physicochemical properties as well as on the surface and conformation properties of the proteins. Different behaviors are also reported for complex multiple protein solutions.

  20. Optical Sensors for Biomolecules Using Nanoporous Sol-Gel Materials

    Science.gov (United States)

    Fang, Jonathan; Zhou, Jing C.; Lan, Esther H.; Dunn, Bruce; Gillman, Patricia L.; Smith, Scott M.

    2004-01-01

    An important consideration for space missions to Mars is the ability to detect biosignatures. Solid-state sensing elements for optical detection of biological entities are possible using sol-gel based biologically active materials. We have used these materials as optical sensing elements in a variety of bioassays, including immunoassays and enzyme assays. By immobilizing an appropriate biomolecule in the sol-gel sensing element, we have successfully detected analytes such as amino acids and hormones. In the case of the amino acid glutamate, the enzyme glutamate dehydrogenase was the immobilized molecule, whereas in the case of the hormone cortisol, an anti-cortisol antibody was immobilized in the sensing element. In this previous work with immobilized enzymes and antibodies, excellent sensitivity and specificity were demonstrated in a variety of formats including bulk materials, thin films and fibers. We believe that the sol-gel approach is an attractive platform for bioastronautics sensing applications because of the ability to detect a wide range of entities such as amino acids, fatty acids, hopanes, porphyrins, etc. The sol-gel approach produces an optically transparent 3D silica matrix that forms around the biomolecule of interest, thus stabilizing its structure and functionality while allowing for optical detection. This encapsulation process protects the biomolecule and leads to a more "rugged" sensor. The nanoporous structure of the sol-gel matrix allows diffusion of small target molecules but keeps larger, biomolecules immobilized in the pores. We are currently developing these biologically active sol-gel materials into small portable devices for on-orbit cortisol detection

  1. The first search for glycine and other biomolecules

    CERN Document Server

    Storey, J W V

    2012-01-01

    In the 1970s the microwave spectroscopy group at Monash University became the first in the world to determine the spectral frequencies of urea, glycine, and several other biomolecules. We immediately searched for these at Parkes, using existing centimetre-wave receivers plus newly built receivers that operated at frequencies as high as 75GHz (and used just the central 17 m of the dish). Although these searches were largely unsuccessful, they helped launch the now flourishing field of astrobiology.

  2. Models and algorithms for biomolecules and molecular networks

    CERN Document Server

    DasGupta, Bhaskar

    2016-01-01

    By providing expositions to modeling principles, theories, computational solutions, and open problems, this reference presents a full scope on relevant biological phenomena, modeling frameworks, technical challenges, and algorithms. * Up-to-date developments of structures of biomolecules, systems biology, advanced models, and algorithms * Sampling techniques for estimating evolutionary rates and generating molecular structures * Accurate computation of probability landscape of stochastic networks, solving discrete chemical master equations * End-of-chapter exercises

  3. Transition-Metal-Free Biomolecule-Based Flexible Asymmetric Supercapacitors.

    Science.gov (United States)

    Yang, Yun; Wang, Hua; Hao, Rui; Guo, Lin

    2016-09-01

    A transition-metal-free asymmetric supercapacitor (ASC) is successfully fabricated based on an earth-abundant biomass derived redox-active biomolecule, named lawsone. Such an ASC exhibits comparable or even higher energy densities than most of the recently reported transition-metal-based ASCs, and this green ASC generation from renewable resources is promising for addressing current issues of electronic hazard processing, high cost, and unsustainability.

  4. Renewable-Biomolecule-Based Full Lithium-Ion Batteries.

    Science.gov (United States)

    Hu, Pengfei; Wang, Hua; Yang, Yun; Yang, Jie; Lin, Jie; Guo, Lin

    2016-05-01

    A renewable-biomolecule-based full lithium-ion battery is successfully fabricated for the first time. Naturally derivable emodin and humic acid based electrodes are used as cathode and anode, respectively. The as-assembled batteries exhibit superb specific capacity and substantial operating voltage capable of powering a wearable electronic watch, suggesting the great potential for practical applications with the significant merits of sustainability and biocompatibility.

  5. Magnetic-based biomolecule detection using giant magnetoresistance sensors

    Science.gov (United States)

    Kokkinis, G.; Jamalieh, M.; Cardoso, F.; Cardoso, S.; Keplinger, F.; Giouroudi, I.

    2015-05-01

    This paper presents a novel microfluidic chip for in-vitro detection of biomolecules tagged by magnetic microparticles (MAPs) suspended in a static fluid. The system consists of two microfluidic channels: a reference channel in which bare MAPs are suspended and a detection channel in which magnetically tagged biomolecules are suspended (LMAPs). The LMAPs are functionalized MAPs (of the same magnetic volume as the ones in the reference channel) with attached biomolecules. The overall, non-magnetic volume of the LMAPs is greater than that of the bare MAPs. Current carrying microconductors are positioned underneath the channels in order to impose a magnetic field gradient to the MAPs and LMAPs and move them from the inlet to the outlet of the channels without flow. The innovative aspect of the proposed method is that the induced velocity on the MAPs and LMAPs, while imposed to the same magnetic field gradient, is inversely proportional to their overall, non-magnetic volume. This is due to the enhanced Stokes drag force exerted on the LMAPs, resulting from the greater volume and altered hydrodynamic shape. This induced velocity is measured by utilizing Giant Magnetoresistance (GMR) sensor pairs fabricated underneath the first and the last microconductors. Detected differences in velocity between the LMAPs and the reference MAPs indicate the presence of biomolecules in the static liquid sample. We also present a novel method for signal acquisition and demodulation: expensive function generators, data acquisition devices, and lock-in amplifiers were substituted by a generic PC sound card and an algorithm combining the Fast Fourier Transform of the signal with a peak detection routine. Experiments with functionalized MAPs and magnetically tagged Escherichia coli (representing the LMAPs) were carried out as a proof of concept. In order to identify the detection limit of the GMR sensor, single MAP (2.8 μm diameter) detection was performed.

  6. Functional nanoprobes for ultrasensitive detection of biomolecules: an update.

    Science.gov (United States)

    Xu, Jing-Juan; Zhao, Wei-Wei; Song, Shiping; Fan, Chunhai; Chen, Hong-Yuan

    2014-03-07

    With the rapidly increasing demands for ultrasensitive biodetection, the design and applications of functional nanoprobes have attracted substantial interest for biosensing with optical, electrochemical, and various other means. In particular, given the comparable sizes of nanomaterials and biomolecules, there exists plenty of opportunities to develop functional nanoprobes with biomolecules for highly sensitive and selective biosensing. Over the past decade, numerous nanoprobes have been developed for ultrasensitive bioaffinity sensing of proteins and nucleic acids in both laboratory and clinical applications. In this review, we provide an update on the recent advances in this direction, particularly in the past two years, which reflects new progress since the publication of our last review on the same topic in Chem. Soc. Rev. The types of probes under discussion include: (i) nanoamplifier probes: one nanomaterial loaded with multiple biomolecules; (ii) quantum dots probes: fluorescent nanomaterials with high brightness; (iii) superquenching nanoprobes: fluorescent background suppression; (iv) nanoscale Raman probes: nanoscale surface-enhanced Raman resonance scattering; (v) nanoFETs: nanomaterial-based electrical detection; and (vi) nanoscale enhancers: nanomaterial-induced metal deposition.

  7. The nano revolution: bottom-up manufacturing with biomolecules

    Science.gov (United States)

    Li, Yi-Fen; Li, Jing; Paavola, Chad; Kagawa, Hiromi; Chan, Suzanne L.; Trent, Jonathan D.

    2007-05-01

    As the nano-scale becomes a focus for engineering electronic, photonic, medical, and other important devices, an unprecedented role for biomolecules is emerging to address one of the most formidable problems in nano-manufacturing: precise manipulation and organization of matter on the nano-scale. Biomolecules are a solution to this problem because they themselves are nanoscale particles with intrinsic properties that allow them to precisely self-assemble and self-organize into the amazing diversity of structures observed in nature. Indeed, there is ample evidence that the combination of molecular recognition and self-assembly combined with mutation, selection, and replication have the potential to create structures that could truly revolutionize manufacturing processes in many sectors of industry. Genetically engineered biomolecules are already being used to make the next generation of nano-scale templates, nano-detailed masks, and molecular scaffolds for the future manufacturing of electronic devices, medical diagnostic tools, and chemical engineering interfaces. Here we present an example of this type of technology by showing how a protein can be genetically modified to form a new structure and coated with metal to lead the way to producing "nano-wires," which may ultimately become the basis for self-assembled circuitry.

  8. Applications of polymers for biomolecule immobilization in electrochemical biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Teles, F.R.R. [IBB - Instituto de Biotecnologia e Bioengenharia, Centro de Engenharia Biologica e Quimica, Instituto Superior Tecnico, Avenida Rovisco Pais, 1049-001 Lisboa (Portugal); Fonseca, L.P. [IBB - Instituto de Biotecnologia e Bioengenharia, Centro de Engenharia Biologica e Quimica, Instituto Superior Tecnico, Avenida Rovisco Pais, 1049-001 Lisboa (Portugal)], E-mail: luis.fonseca@ist.utl.pt

    2008-12-01

    Polymers are becoming inseparable from biomolecule immobilization strategies and biosensor platforms. Their original role as electrical insulators has been progressively substituted by their electrical conductive abilities, which opens a new and broad scope of applications. In addition, recent advances in diagnostic chips and microfluidic systems, together with the requirements of mass-production technologies, have raised the need to replace glass by polymeric materials, which are more suitable for production through simple manufacturing processes. Conducting polymers (CPs), in particular, are especially amenable for electrochemical biosensor development for providing biomolecule immobilization and for rapid electron transfer. It is expected that the combination of known polymer substrates, but also new transducing and biocompatible interfaces, with nanobiotechnological structures, like nanoparticles, carbon nanotubes (CNTs) and nanoengineered 'smart' polymers, may generate composites with new and interesting properties, providing higher sensitivity and stability of the immobilized molecules, thus constituting the basis for new and improved analytical devices for biomedical and other applications. This review covers the state-of-the-art and main novelties about the use of polymers for immobilization of biomolecules in electrochemical biosensor platforms.

  9. Repulsive effects of hydrophobic diamond thin films on biomolecule detection

    Energy Technology Data Exchange (ETDEWEB)

    Ruslinda, A. Rahim, E-mail: ruslindarahim@gmail.com [Institute of Nano Electronic Engineering, Universiti Malaysia Perlis, Jln Kgr-Alor Setar, Seriab, 01000 Kangar, Perlis (Malaysia); Department of Nano Science and Nano Engineering, School of Advance Science and Engineering, Ohkubo 3-4-1, Shinjuku, 169-8555 Tokyo (Japan); Ishiyama, Y. [Department of Nano Science and Nano Engineering, School of Advance Science and Engineering, Ohkubo 3-4-1, Shinjuku, 169-8555 Tokyo (Japan); Penmatsa, V. [Department of Mechanical and Materials Engineering, Florida International University, 10555 West Flagler Street, Miami, FL 33174 (United States); Ibori, S.; Kawarada, H. [Department of Nano Science and Nano Engineering, School of Advance Science and Engineering, Ohkubo 3-4-1, Shinjuku, 169-8555 Tokyo (Japan)

    2015-02-15

    Highlights: • We report the effect of fluorine plasma treatment on diamond thin film to resist the nonspecific adsorption of biomolecules. • The diamond thin film were highly hydrophobic with a surface energy value of ∼25 mN/m. • The repulsive effect shows excellent binding efficiency for both DNA and HIV-1 Tat protein. - Abstract: The repulsive effect of hydrophobic diamond thin film on biomolecule detection, such as single-nucleotide polymorphisms and human immunodeficiency virus type 1 trans-activator of transcription peptide protein detection, was investigated using a mixture of a fluorine-, amine-, and hydrogen-terminated diamond surfaces. These chemical modifications lead to the formation of a surface that effectively resists the nonspecific adsorption of proteins and other biomolecules. The effect of fluorine plasma treatment on elemental composition was also investigated via X-ray photoelectron spectroscopy (XPS). XPS results revealed a fluorocarbon layer on the diamond thin films. The contact angle measurement results indicated that the fluorine-treated diamond thin films were highly hydrophobic with a surface energy value of ∼25 mN/m.

  10. Potentiometric sensors doped with biomolecules as a new approach to small molecule/biomolecule binding kinetics analysis.

    Science.gov (United States)

    Daems, D; De Wael, K; Vissenberg, K; Van Camp, G; Nagels, L

    2014-04-15

    The most successful binding kinetics analysis systems at this moment include surface plasmon resonance (SPR), quartz microcrystal balance (QMB) and surface acoustic wave (SAW). Although these are powerful methods, they generally are complex, expensive and require the use of monolayers. Here, we report on potentiometric sensors as an inexpensive and simple alternative to do binding kinetics analysis between small molecules in solution and biomolecules (covalently) attached in a biopolymer sensor coating layer. As an example, dopamine and an anti-dopamine aptamer were used as the small molecule and the biomolecule respectively. Binding between both follows a Langmuir adsorption type model and creates a surface potential. The system operates in Flow Injection Analysis mode (FIA). Besides being an interesting new binding kinetics tool, the approach allows systematic design of potentiometric biosensors (in the present study a dopamine sensor), and gives new insights into the functioning of ion-selective electrodes (ISE's).

  11. Design and characterization of nanomaterial-biomolecule conjugates

    Science.gov (United States)

    Yim, Tae-Jin

    In the field of nanobiotechnology, nanoscale dimensions result in physical properties that differ from more conventional bulk material state. The integration of nanomaterials with biomolecules has begun to be used for unique physical properties, and for biological specific recognition, thereby leading to novel nanomaterial-biomolecule conjugates. The direction of this dissertation is to develop biocatalytic nanomaterial-biomolecule conjugates and to characterize them. For this, biological catalysts are employed to combine with nanomaterials. Two large parts include functional ization of nanomaterials with biomolecules and assembly of nanomaterials using a biological catalyst. First part of this thesis work is the exploration of the biocatalytic properties of nanomaterial-biomolecule conjugates. Si nanocolumns have higher surface area which leads more amount of biocatalytis immobilization than flat Si wafer with the same projected area. The enhanced activity of soybean peroxidase (SBP) immobilized onto Si nanocolumns as novel nanostructured supports is focused. Next, the catalytic activity of immobilized DNAzyme onto multiwalled carbon nanotubes (MWNTs) is compared to that in solution phase, and multiple turnovers are examined. The relationship between hybridization efficiency and activity is investigated as a function of surface density of DNAzyme on MWNTs. Then, cellular delivery of silica nanoparticle-protein conjugates is visually confirmed and therefore the intracellular function of a protein delivered by silica nanoparticle-protein conjugates is proved. For one example of the intracellular function, stable SBP immobilized onto silica nanoparticles to activate a prodrug is demonstrated. Second part of this thesis work is the formation of nanostructured materials through the enzymatic assembly of single-walled carbon nanotubes (SWNTs). Enzymatic polymerization of a phenol compound is applied to the bridging of two or more SWNTs functionalized with phenol

  12. Quantum Simulations of Solvated Biomolecules Using Hybrid Methods

    Science.gov (United States)

    Hodak, Miroslav

    2009-03-01

    One of the most important challenges in quantum simulations on biomolecules is efficient and accurate inclusion of the solvent, because the solvent atoms usually outnumber those in the biomolecule of interest. We have developed a hybrid method that allows for explicit quantum-mechanical treatment of the solvent at low computational cost. In this method, Kohn-Sham (KS) density functional theory (DFT) is combined with an orbital-free (OF) DFT. Kohn-Sham (KS) DFT is used to describe the biomolecule and its first solvation shells, while the orbital-free (OF) DFT is employed for the rest of the solvent. The OF part is fully O(N) and capable of handling 10^5 solvent molecules on current parallel supercomputers, while taking only ˜ 10 % of the total time. The compatibility between the KS and OF DFT methods enables seamless integration between the two. In particular, the flow of solvent molecules across the KS/OF interface is allowed and the total energy is conserved. As the first large-scale applications, the hybrid method has been used to investigate the binding of copper ions to proteins involved in prion (PrP) and Parkinson's diseases. Our results for the PrP, which causes mad cow disease when misfolded, resolve a contradiction found in experiments, in which a stronger binding mode is replaced by a weaker one when concentration of copper ions is increased, and show how it can act as a copper buffer. Furthermore, incorporation of copper stabilizes the structure of the full-length PrP, suggesting its protective role in prion diseases. For alpha-synuclein, a Parkinson's disease (PD) protein, we show that Cu binding modifies the protein structurally, making it more susceptible to misfolding -- an initial step in the onset of PD. In collaboration with W. Lu, F. Rose and J. Bernholc.

  13. Specific and quantitative labeling of biomolecules using click chemistry.

    Science.gov (United States)

    Horisawa, Kenichi

    2014-01-01

    Specific and highly efficient fluorescent labeling techniques for biomolecules, especially for proteins, are required for the quantitative analyses of bio-phenomena and for subsequent systems biology. Although expression of exogenous proteins fused with fluorescent tags, such as green fluorescent protein, is the most widely used method for quantitative bio-analysis, the following problems need to be considered carefully: (1) precise stoichiometric control in living cells is difficult, and (2) the bulkiness of the fluorescent tags restricts analysis of the inherent physical and biological properties of the proteins. Therefore, novel techniques to specifically and stoichiometrically label intrinsic proteins or other biomolecules in living cells should be developed. Click chemistry reactions (e.g., Huisgen cycloaddition and Staudinger ligation) are the most promising approaches for this purpose, because these chemical reactions have following advantages: (1) bioorthogonal reactions; (2) mild reaction conditions suitable for fragile biomolecules, cells, and tissues; (3) extremely high reaction ratio; (4) small size of the functional groups for the cross-coupling reactions; (5) stable covalent bonding; and (6) simple metabolic labeling procedures in living cells, using various biomolecular analogs. Diverse quantitative biological studies have been carried out using this technology (e.g., quantification of novel synthesized proteins and observation of post-translational modifications). In this review, I explain the basics of chemical probing with click chemistry, and discuss its recent applications in the field of quantitative biology. Furthermore, I discuss the capability, significance, and future of the chemical probing of proteins, with an emphasis on the use of click chemistry in the field of the quantitative biology.

  14. Specific and quantitative labeling of biomolecules using click chemistry

    Directory of Open Access Journals (Sweden)

    Kenichi eHorisawa

    2014-11-01

    Full Text Available Specific and highly efficient fluorescent labeling techniques for biomolecules, especially for proteins, are required for the quantitative analyses of bio-phenomena and for subsequent systems biology. Although expression of exogenous proteins fused with fluorescent tags, such as green fluorescent protein, is the most widely used method for quantitative bio-analysis, the following problems need to be considered carefully: 1 precise stoichiometric control in living cells is difficult, and 2 the bulkiness of the fluorescent tags restricts analysis of the inherent physical and biological properties of the proteins. Therefore, novel techniques to specifically and stoichiometrically label intrinsic proteins or other biomolecules in living cells should be developed. Click chemistry reactions (e.g., Huisgen cycloaddition and Staudinger ligation are the most promising approaches for this purpose, because these chemical reactions have following advantages: 1 bioorthogonal reactions; 2 mild reaction conditions suitable for fragile biomolecules, cells, and tissues; 3 extremely high reaction ratio; 4 small size of the functional groups for the cross-coupling reactions; 5 stable covalent bonding; and 6 simple metabolic labeling procedures in living cells, using various biomolecular analogs. Diverse quantitative biological studies have been carried out using this technology (e.g., quantification of novel synthesized proteins and observation of post-translational modifications. In this review, I explain the basics of chemical probing with click chemistry, and discuss its recent applications in the field of quantitative biology. Furthermore, I discuss the capability, significance, and future of the chemical probing of proteins, with an emphasis on the use of click chemistry in the field of the quantitative biology.

  15. Simple approach to study biomolecule adsorption in polymeric microfluidic channels.

    Science.gov (United States)

    Gubala, Vladimir; Siegrist, Jonathan; Monaghan, Ruairi; O'Reilly, Brian; Gandhiraman, Ram Prasad; Daniels, Stephen; Williams, David E; Ducrée, Jens

    2013-01-14

    Herein a simple analytical method is presented for the characterization of biomolecule adsorption on cyclo olefin polymer (COP, trade name: Zeonor(®)) substrates which are widely used in microfluidic lab-on-a-chip devices. These Zeonor(®) substrates do not possess native functional groups for specific reactions with biomolecules. Therefore, depending on the application, such substrates must be functionalized by surface chemistry methods to either enhance or suppress biomolecular adsorption. This work demonstrates a microfluidic method for evaluating the adsorption of antibodies and oligonucleotides surfaces. The method uses centrifugal microfluidic flow-through chips and can easily be implemented using common equipment such as a spin coater. The working principle is very simple. The user adds 40 L of the solution containing the sample to the starting side of a microfluidic channel, where it is moved through by centrifugal force. Some molecules are adsorbed in the channel. The sample is then collected at the other end in a small reservoir and the biomolecule concentration is measured. As a pilot application, we characterized the adsorption of goat anti-human IgG and a 20-mer DNA on Zeonor(®), and on three types of functionalized Zeonor: 3-aminopropyltriethoxysilane (APTES) modified surface with mainly positive charge, negatively charged surface with immobilized bovine serum albumin (BSA), and neutral, hydrogel-like film with polyethylene glycol (PEG) characteristics. This simple analytical approach adds to the fundamental understanding of the interaction forces in real, microfluidic systems. This method provides a straightforward and rapid way to screen surface compositions and chemistry, and relate these to their effects on the sensitivity and resistance to non-specific binding of bioassays using them. In an additional set of experiments, the surface area of the channels in this universal microfluidic chip was increased by precision milling of microscale

  16. Low-energy electron scattering from molecules, biomolecules and surfaces

    CERN Document Server

    Carsky, Petr

    2011-01-01

    Since the turn of the 21st century, the field of electron molecule collisions has undergone a renaissance. The importance of such collisions in applications from radiation chemistry to astrochemistry has flowered, and their role in industrial processes such as plasma technology and lighting are vital to the advancement of next generation devices. Furthermore, the development of the scanning tunneling microscope highlights the role of such collisions in the condensed phase, in surface processing, and in the development of nanotechnology.Low-Energy Electron Scattering from Molecules, Biomolecule

  17. Simple approach to study biomolecule adsorption in polymeric microfluidic channels

    Energy Technology Data Exchange (ETDEWEB)

    Gubala, Vladimir, E-mail: V.Gubala@kent.ac.uk [Biomedical Diagnostics Institute (BDI), National Centre for Sensor Research (NCSR), Dublin City University, Dublin 9 (Ireland); Medway School of Pharmacy, University of Kent, Central Avenue, Anson 120, Chatham Maritime, Kent ME4 4TB (United Kingdom); Siegrist, Jonathan; Monaghan, Ruairi; O' Reilly, Brian; Gandhiraman, Ram Prasad [Biomedical Diagnostics Institute (BDI), National Centre for Sensor Research (NCSR), Dublin City University, Dublin 9 (Ireland); Daniels, Stephen [Biomedical Diagnostics Institute (BDI), National Centre for Sensor Research (NCSR), Dublin City University, Dublin 9 (Ireland); National Centre for Plasma Science and Technology (NCPST), Dublin City University, Dublin 9 (Ireland); Williams, David E. [Biomedical Diagnostics Institute (BDI), National Centre for Sensor Research (NCSR), Dublin City University, Dublin 9 (Ireland); MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical Sciences, University of Auckland, Auckland 1142 (New Zealand); Ducree, Jens [Biomedical Diagnostics Institute (BDI), National Centre for Sensor Research (NCSR), Dublin City University, Dublin 9 (Ireland)

    2013-01-14

    Highlights: Black-Right-Pointing-Pointer A simple tool to assess biomolecule adsorption onto the surfaces of microchannels. Black-Right-Pointing-Pointer Development for dilution by surface-adsorption based depletion of protein samples. Black-Right-Pointing-Pointer It can easily be done using a readily available apparatus like a spin-coater. Black-Right-Pointing-Pointer The assessment tool is facile and quantitative. Black-Right-Pointing-Pointer Straightforward comparison of different surface chemistries. - Abstract: Herein a simple analytical method is presented for the characterization of biomolecule adsorption on cyclo olefin polymer (COP, trade name: Zeonor{sup Registered-Sign }) substrates which are widely used in microfluidic lab-on-a-chip devices. These Zeonor{sup Registered-Sign} substrates do not possess native functional groups for specific reactions with biomolecules. Therefore, depending on the application, such substrates must be functionalized by surface chemistry methods to either enhance or suppress biomolecular adsorption. This work demonstrates a microfluidic method for evaluating the adsorption of antibodies and oligonucleotides surfaces. The method uses centrifugal microfluidic flow-through chips and can easily be implemented using common equipment such as a spin coater. The working principle is very simple. The user adds 40 L of the solution containing the sample to the starting side of a microfluidic channel, where it is moved through by centrifugal force. Some molecules are adsorbed in the channel. The sample is then collected at the other end in a small reservoir and the biomolecule concentration is measured. As a pilot application, we characterized the adsorption of goat anti-human IgG and a 20-mer DNA on Zeonor{sup Registered-Sign }, and on three types of functionalized Zeonor: 3-aminopropyltriethoxysilane (APTES) modified surface with mainly positive charge, negatively charged surface with immobilized bovine serum albumin (BSA), and

  18. Raman spectroscopy detection of biomolecules in biocrusts from differing environmental conditions

    Science.gov (United States)

    Miralles, I.; Jorge-Villar, S. E.; van Wesemael, B.; Lázaro, R.

    2017-01-01

    Lichens and cyanobacteria colonize inhospitable places covering a wide climate range due to their different survival strategies, such as the synthesis of protective biomolecules. The effect of ecological factors on the synthesis of biomolecules has not been widely analysed. This study aimed to assess the effects of four factors (species, microclimate, seasonality and hydration state) and their interactions on the biomolecule frequency detected by Raman Spectroscopy. We included cyanobacterial biocrusts, and the lichens Diploschistes diacapsis, Squamarina lentigera, and Lepraria isidiata; two contrasted microclimates (typical and marginal), two contrasted seasons (hot and dry vs cool and wet) and two hydration states (dry and wet). "Species" was the most influential factor in the identity and frequency of the main biomolecules. Microclimatic differences in the range of the local specific habitats only influenced the biomolecules in cyanobacteria. There was a quadruple interaction among the factors, the effects being different mainly depending on the species. At D. diacapsis, the production of their main biomolecules depended on microclimate, although it also depended on seasonality. Nevertheless, in L. isidiata and S. lentigera microclimatic differences did not significantly affect the production of biomolecules. In the lichen species, the microhabitats exposed to relatively larger incident radiation did not show significantly larger relative frequency of photoprotective biomolecules. No clear connection between higher production of oxalates and drier microhabitats was found, suggesting that the synthesis of oxalates is not related to water reserve strategy. The pros and cons of monitor biomolecules in biocrust by Raman spectrometry were also discussed.

  19. A transistor-based biosensor for the extraction of physical properties from biomolecules

    Science.gov (United States)

    Kim, Sungho; Baek, David; Kim, Jee-Yeon; Choi, Sung-Jin; Seol, Myeong-Lok; Choi, Yang-Kyu

    2012-08-01

    An analytical technique is proposed that uses an asymmetric double-gate field-effect transistor (FET) structure to characterize the electrical properties of biomolecules, including their permittivity and charge density. Using a simple measurement with the proposed FET structure, we are able to extract the physical properties (i.e., permittivity and charge density) of biomolecules. A reliable analytical tool for the characterization of biomolecules can be provided by the proposed FET structure without a complex measurement system. It is expected that the proposed method will be expanded into a universal analysis technique for the electrical evaluation of biomolecules in applications beyond biosensing.

  20. Worry as an Uncertainty-Associated Emotion: Exploring the Role of Worry in Health Information Seeking.

    Science.gov (United States)

    Lee, Sun Young; Hawkins, Robert P

    2016-08-01

    This study was carried out to understand how and why worry motivates health-related information seeking, and whether worry decreases after obtaining health-related information. It was proposed that worry influences health-related information-seeking behavior indirectly through cancer patients' desire for obtaining additional information. It was further expected that perceived knowledge about cancer could be increased after 2 months of searching for health information over the Internet, which would subsequently affect levels of worry. Using panel data collected from 224 women diagnosed with breast cancer, worry was found to predict patients' health information seeking via the perceived need for additional information. The results further showed significant increases in patients' perceived knowledge about breast cancer and decreased levels of worry after the seeking of health information for 2 months. Theoretical and practical implications of the findings are discussed.

  1. Biosurfactants: Multifunctional Biomolecules of the 21st Century

    Directory of Open Access Journals (Sweden)

    Danyelle Khadydja F. Santos

    2016-03-01

    Full Text Available In the era of global industrialisation, the exploration of natural resources has served as a source of experimentation for science and advanced technologies, giving rise to the manufacturing of products with high aggregate value in the world market, such as biosurfactants. Biosurfactants are amphiphilic microbial molecules with hydrophilic and hydrophobic moieties that partition at liquid/liquid, liquid/gas or liquid/solid interfaces. Such characteristics allow these biomolecules to play a key role in emulsification, foam formation, detergency and dispersal, which are desirable qualities in different industries. Biosurfactant production is considered one of the key technologies for development in the 21st century. Besides exerting a strong positive impact on the main global problems, biosurfactant production has considerable importance to the implantation of sustainable industrial processes, such as the use of renewable resources and “green” products. Biodegradability and low toxicity have led to the intensification of scientific studies on a wide range of industrial applications for biosurfactants in the field of bioremediation as well as the petroleum, food processing, health, chemical, agricultural and cosmetic industries. In this paper, we offer an extensive review regarding knowledge accumulated over the years and advances achieved in the incorporation of biomolecules in different industries.

  2. The nanoparticle biomolecule corona: lessons learned - challenge accepted?

    Science.gov (United States)

    Docter, D; Westmeier, D; Markiewicz, M; Stolte, S; Knauer, S K; Stauber, R H

    2015-10-07

    Besides the wide use of engineered nanomaterials (NMs) in technical products, their applications are not only increasing in biotechnology and biomedicine, but also in the environmental field. While the physico-chemical properties and behaviour of NMs can be characterized accurately under idealized conditions, this is no longer the case in complex physiological or natural environments. Herein, proteins and other biomolecules rapidly bind to NMs, forming a protein/biomolecule corona that critically affects the NMs' (patho)biological and technical identities. As the corona impacts the in vitro and/or in vivo NM applications in humans and ecosystems, a mechanistic understanding of its relevance and of the biophysical forces regulating corona formation is mandatory. Based on recent insights, we here critically review and present an updated concept of corona formation and evolution. We comment on how corona signatures may be linked to effects at the nano-bio interface in physiological and environmental systems. In order to comprehensively analyse corona profiles and to mechanistically understand the coronas' biological/ecological impact, we present a tiered multidisciplinary approach. To stimulate progress in this field, we introduce the potential impact of the corona for NM-microbiome-(human)host interactions and the novel concept of 'nanologicals', i.e., the nanomaterial-specific targeting of molecular machines. We conclude by discussing the relevant challenges that still need to be resolved in this field.

  3. Novel in Vitro Efficiency of Chitosan Biomolecule Against Trichomonas Gallinae

    Directory of Open Access Journals (Sweden)

    SH Pourseyed

    2012-02-01

    Full Text Available Background: Development of new natural agents for parasitic diseases treatment has unexpectedly increased to overcome effectively against emergence and re-emergence of parasitic diseases, the appearance of drug resistant organisms and toxic side effects of current agents. The aim of the study was to evaluate antiprotozoal activities of chitosan biomolecule on trophozoites of Trichomonas gallinae.Methods: The antitrichomonal activity of various low molecular weight chitosan concentrations including 125, 250, 500 and 1250 μg ml-1 against T. gallinae trophozoites cultured in trypticase-yeast extract-maltose medium supplemented with heat-inactivated cold horse serum was evaluated in vitro. Samples containing medium without chitosan were also assayed as controls.Results: The mortality rates at 0, 3 and 6 h post treatment with all concentrations were significantly different from control group (P<0.05. Treated trophozoites showed more susceptibility to the highest concentration reaching mortality rate of 100% at 3h post inoculation. However, at this time, results for 125, 250 and 500 μg ml-1 were 93%, 95% and 96.7%, respectively.Conclusion: The results demonstrate that the application of chitosan biomolecule is a promising option for treatment of trichomoniasis in pigeons.

  4. Biosurfactants: Multifunctional Biomolecules of the 21st Century.

    Science.gov (United States)

    Santos, Danyelle Khadydja F; Rufino, Raquel D; Luna, Juliana M; Santos, Valdemir A; Sarubbo, Leonie A

    2016-03-18

    In the era of global industrialisation, the exploration of natural resources has served as a source of experimentation for science and advanced technologies, giving rise to the manufacturing of products with high aggregate value in the world market, such as biosurfactants. Biosurfactants are amphiphilic microbial molecules with hydrophilic and hydrophobic moieties that partition at liquid/liquid, liquid/gas or liquid/solid interfaces. Such characteristics allow these biomolecules to play a key role in emulsification, foam formation, detergency and dispersal, which are desirable qualities in different industries. Biosurfactant production is considered one of the key technologies for development in the 21st century. Besides exerting a strong positive impact on the main global problems, biosurfactant production has considerable importance to the implantation of sustainable industrial processes, such as the use of renewable resources and "green" products. Biodegradability and low toxicity have led to the intensification of scientific studies on a wide range of industrial applications for biosurfactants in the field of bioremediation as well as the petroleum, food processing, health, chemical, agricultural and cosmetic industries. In this paper, we offer an extensive review regarding knowledge accumulated over the years and advances achieved in the incorporation of biomolecules in different industries.

  5. Strategic Asset Seeking by EMNEs

    DEFF Research Database (Denmark)

    Petersen, Bent; Seifert, Jr., Rene E.

    2014-01-01

    as the more relevant concept to use when explaining strategic asset seeking of EMNEs. A set of propositions are formulated to guide empirical testing. Originality/value: The insights gained from using the springboard perspective and the LOO concept are non-trivial: They basically predict future dominance...

  6. CHINA SEEKS REGIONAL ENERGY COOPERATION

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    China is seeking to diversify channels for energy cooperation as it faces mounting challenges from surging energy demand, geopolitical risks and price volatility. The endowment and distribution of China's resources does not match the current situation of China's economic development. Those are the opinions aired by officials and experts at an international expo recently held in West China's Xinjiang Uygur Autonomous Region.

  7. A photocleavable affinity tag for the enrichment of alkyne-modified biomolecules

    NARCIS (Netherlands)

    Koopmans, Timo; Dekker, Frank J.; Martin, Nathaniel I.

    2012-01-01

    A new photocleavable affinity tag for use in the enrichment of alkyne-labelled biomolecules is reported. The tag is prepared via a concise synthetic route using readily available materials. The photolytic conditions employed for cleavage of the tag provide for a clean release of enriched biomolecule

  8. High-Speed AFM Reveals the Dynamics of Single Biomolecules at the Nanometer Scale

    NARCIS (Netherlands)

    Katan, A.J.; Dekker, C.

    2011-01-01

    Atomic force microscopy allows visualization of biomolecules with nanometer resolution under physiological conditions. Recent advances have improved the time resolution of the technique from minutes to tens of milliseconds, meaning that it is now possible to watch single biomolecules in action in re

  9. Sustained delivery of biomolecules from gelatin carriers for applications in bone regeneration

    NARCIS (Netherlands)

    Song, J.; Leeuwenburgh, S.C.G.

    2014-01-01

    Local delivery of therapeutic biomolecules to stimulate bone regeneration has matured considerably during the past decades, but control over the release of these biomolecules still remains a major challenge. To this end, suitable carriers that allow for tunable spatial and temporal delivery of biomo

  10. Stereoselective assembly of amino acid-based metal-biomolecule nanofibers.

    Science.gov (United States)

    Wu, Hong; Tian, Chunyong; Zhang, Yufei; Yang, Chen; Zhang, Songping; Jiang, Zhongyi

    2015-04-14

    A series of amino acid-based metal-biomolecule nanofibers are fabricated through a coordination-directed assembly process. The chirality and carbon chain length of the amino acids exert a pronounced influence on the assembly process. This study may be extended to design diverse kinds of 1-D metal-biomolecule frameworks (MBioFs).

  11. Sustained delivery of biomolecules from gelatin carriers for applications in bone regeneration.

    Science.gov (United States)

    Song, Jiankang; Leeuwenburgh, Sander Cg

    2014-08-01

    Local delivery of therapeutic biomolecules to stimulate bone regeneration has matured considerably during the past decades, but control over the release of these biomolecules still remains a major challenge. To this end, suitable carriers that allow for tunable spatial and temporal delivery of biomolecules need to be developed. Gelatin is one of the most widely used natural polymers for the controlled and sustained delivery of biomolecules because of its biodegradability, biocompatibility, biosafety and cost-effectiveness. The current study reviews the applications of gelatin as carriers in form of bulk hydrogels, microspheres, nanospheres, colloidal gels and composites for the programmed delivery of commonly used biomolecules for applications in bone regeneration with a specific focus on the relationship between carrier properties and delivery characteristics.

  12. A new algorithm for construction of coarse-grained sites of large biomolecules.

    Science.gov (United States)

    Li, Min; Zhang, John Z H; Xia, Fei

    2016-04-05

    The development of coarse-grained (CG) models for large biomolecules remains a challenge in multiscale simulations, including a rigorous definition of CG representations for them. In this work, we proposed a new stepwise optimization imposed with the boundary-constraint (SOBC) algorithm to construct the CG sites of large biomolecules, based on the s cheme of essential dynamics CG. By means of SOBC, we can rigorously derive the CG representations of biomolecules with less computational cost. The SOBC is particularly efficient for the CG definition of large systems with thousands of residues. The resulted CG sites can be parameterized as a CG model using the normal mode analysis based fluctuation matching method. Through normal mode analysis, the obtained modes of CG model can accurately reflect the functionally related slow motions of biomolecules. The SOBC algorithm can be used for the construction of CG sites of large biomolecules such as F-actin and for the study of mechanical properties of biomaterials.

  13. Bifunctional chelating agent for the design and development of site specific radiopharmaceuticals and biomolecule conjugation strategy

    Science.gov (United States)

    Katti, Kattesh V.; Prabhu, Kandikere R.; Gali, Hariprasad; Pillarsetty, Nagavara Kishore; Volkert, Wynn A.

    2003-10-21

    There is provided a method of labeling a biomolecule with a transition metal or radiometal in a site specific manner to produce a diagnostic or therapeutic pharmaceutical compound by synthesizing a P.sub.2 N.sub.2 -bifunctional chelating agent intermediate, complexing the intermediate with a radio metal or a transition metal, and covalently linking the resulting metal-complexed bifunctional chelating agent with a biomolecule in a site specific manner. Also provided is a method of synthesizing the --PR.sub.2 containing biomolecules by synthesizing a P.sub.2 N.sub.2 -bifunctional chelating agent intermediate, complexing the intermediate with a radiometal or a transition metal, and covalently linking the resulting radio metal-complexed bifunctional chelating agent with a biomolecule in a site specific manner. There is provided a therapeutic or diagnostic agent comprising a --PR.sub.2 containing biomolecule.

  14. Efficient extraction strategies of tea (Camellia sinensis) biomolecules.

    Science.gov (United States)

    Banerjee, Satarupa; Chatterjee, Jyotirmoy

    2015-06-01

    Tea is a popular daily beverage worldwide. Modulation and modifications of its basic components like catechins, alkaloids, proteins and carbohydrate during fermentation or extraction process changes organoleptic, gustatory and medicinal properties of tea. Through these processes increase or decrease in yield of desired components are evident. Considering the varied impacts of parameters in tea production, storage and processes that affect the yield, extraction of tea biomolecules at optimized condition is thought to be challenging. Implementation of technological advancements in green chemistry approaches can minimize the deviation retaining maximum qualitative properties in environment friendly way. Existed extraction processes with optimization parameters of tea have been discussed in this paper including its prospects and limitations. This exhaustive review of various extraction parameters, decaffeination process of tea and large scale cost effective isolation of tea components with aid of modern technology can assist people to choose extraction condition of tea according to necessity.

  15. Synthesis of selenium nanorods with assistance of biomolecule

    Indian Academy of Sciences (India)

    S Kannan; K Mohanraj; K Prabhu; S Barathan; G Sivakumar

    2014-12-01

    Nanorods of one-dimensional (1D) trigonal selenium (t-Se) are synthesized using biomolecule substances for five different aging times (1 h, 2 h, 3 h, 1 day and 4 days) by precipitation method. XRD analysis indicates a shift of the (1 0 1) plane towards higher diffraction angle for 1 day aging time. It is observed that the crystallite size decreases with increase in aging time except for an aging period of 4 days. FTIR analysis confirmed that the presence of stretching and bending vibrations of Se–O in both synthesized and commercial selenium samples at 465, 668 and 1118 cm-1. The FESEM micrographs are evident for the changes of rod size as a function of aging time. It is observed that the optical band gap energy is increased with aging time up to 1 day, whereas it decreases in 4 days aging time.

  16. Click-EM for imaging metabolically tagged nonprotein biomolecules.

    Science.gov (United States)

    Ngo, John T; Adams, Stephen R; Deerinck, Thomas J; Boassa, Daniela; Rodriguez-Rivera, Frances; Palida, Sakina F; Bertozzi, Carolyn R; Ellisman, Mark H; Tsien, Roger Y

    2016-06-01

    EM has long been the main technique for imaging cell structures with nanometer resolution but has lagged behind light microscopy in the crucial ability to make specific molecules stand out. Here we introduce click-EM, a labeling technique for correlative light microscopy and EM imaging of nonprotein biomolecules. In this approach, metabolic labeling substrates containing bioorthogonal functional groups are provided to cells for incorporation into biopolymers by endogenous biosynthetic machinery. The unique chemical functionality of these analogs is exploited for selective attachment of singlet oxygen-generating fluorescent dyes via bioorthogonal 'click chemistry' ligations. Illumination of dye-labeled structures generates singlet oxygen to locally catalyze the polymerization of diaminobenzidine into an osmiophilic reaction product that is readily imaged by EM. We describe the application of click-EM in imaging metabolically tagged DNA, RNA and lipids in cultured cells and neurons and highlight its use in tracking peptidoglycan synthesis in the Gram-positive bacterium Listeria monocytogenes.

  17. International students’ information seeking behavior

    DEFF Research Database (Denmark)

    Hyldegård, Jette Seiden

    2016-01-01

    This report presents the first results and reflections from an exploratory case study carried out at The Royal School of Library and Information Science in 2015 on international students’ information seeking behavior. A convenient sample of five international master students participated...... in the study, including a questionnaire and in-depth interviews. The focus was on international students’ private and academic information needs and behavior ‘abroad’ in addition to their experiences of information seeking. Based on the analysis of survey data and participants’ descriptions of incidents...... and academic life and 5) social networks and support for cultural adjustment. Insights into the characteristics of international students’ information needs and behavior may help host institutions serve international students....

  18. Assembly and actuation of nanomaterials using active biomolecules.

    Energy Technology Data Exchange (ETDEWEB)

    Spoerke, Erik David; Thayer, Gayle Echo; de Boer, Maarten Pieter; Bunker, Bruce Conrad; Liu, Jun; Corwin, Alex David; Gaudioso, Jennifer Marie; Sasaki, Darryl Yoshio; Boal, Andrew Kiskadden; Bachand, George David; Trent, Amanda M.; Bachand, Marlene; Rivera, Susan B.; Koch, Steven John

    2005-11-01

    The formation and functions of living materials and organisms are fundamentally different from those of synthetic materials and devices. Synthetic materials tend to have static structures, and are not capable of adapting to the functional needs of changing environments. In contrast, living systems utilize energy to create, heal, reconfigure, and dismantle materials in a dynamic, non-equilibrium fashion. The overall goal of the project was to organize and reconfigure functional assemblies of nanoparticles using strategies that mimic those found in living systems. Active assembly of nanostructures was studied using active biomolecules to drive the organization and assembly of nanocomposite materials. In this system, kinesin motor proteins and microtubules were used to direct the transport and interactions of nanoparticles at synthetic interfaces. In addition, the kinesin/microtubule transport system was used to actively assemble nanocomposite materials capable of storing significant elastic energy. Novel biophysical measurement tools were also developed for measuring the collective force generated by kinesin motor proteins, which will provide insight on the mechanical constraints of active assembly processes. Responsive reconfiguration of nanostructures was studied in terms of using active biomolecules to mediate the optical properties of quantum dot (QD) arrays through modulation of inter-particle spacing and associated energy transfer interaction. Design rules for kinesin-based transport of a wide range of nanoscale cargo (e.g., nanocrystal quantum dots, micron-sized polymer spheres) were developed. Three-dimensional microtubule organizing centers were assembled in which the polar orientation of the microtubules was controlled by a multi-staged assembly process. Overall, a number of enabling technologies were developed over the course of this project, and will drive the exploitation of energy-driven processes to regulate the assembly, disassembly, and dynamic

  19. Recent Advances in Protein Extraction and Chiral Separation of Biomolecules

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Reverse micelles create unique environment in organic media. They are capable of solubilizing hydrophilic biomolecules (e.g., proteins, peptides, amino acids, and DNAs) in their aqueous interior. This feature brings about the practical use of biomaterials in organic media because reverse micelles solubilize them with the intrinsic activity. In this paper, we focus on recent two topics concerning protein extraction and chiral separation of biomolecules using liquid membranes. In the first topic, we present recent attempts to extract proteins from an aqueous solution into isooctane using reverse micelles, and some important operational parameters to achieve an efficient protein transfer are discussed. Furthermore, novel function of reverse micelles as a protein activation medium is introduced. In the reverse micellar phase, denatured proreins were completely reactivated in the reverse micellar solution. The reverse micellar technique is found to be a useful tool not only for protein separation but also for protein refolding. Furthermore, we found that a cyclic ligand carixarene has an extraction ability to set up optimum conditions for protein transfer. In the second topic, we have found that a supported liquid membrane (SLM) encapsulating enzymes shows high enantioselectivity (enantioselective excess value is over 96%) in the transport of racemic pharmaceutical compound ibuprofen. A different experiment also suggests that the α-chymotrypsin-catalyzed reactions droved the enantioselective transport of L-phenylalanine based on the enantioselectivity of the enzyme. The SLM encapsulating the surfactant-enzyme complex enabled the highly enantioselective separation of racemic mixtures. It can be envisioned that arrangement of appropriate enzymes in the SLM system will allow enantioselective separation of various useful organic compounds.

  20. Health information seeking and the World Wide Web: an uncertainty management perspective.

    Science.gov (United States)

    Rains, Stephen A

    2014-01-01

    Uncertainty management theory was applied in the present study to offer one theoretical explanation for how individuals use the World Wide Web to acquire health information and to help better understand the implications of the Web for information seeking. The diversity of information sources available on the Web and potential to exert some control over the depth and breadth of one's information-acquisition effort is argued to facilitate uncertainty management. A total of 538 respondents completed a questionnaire about their uncertainty related to cancer prevention and information-seeking behavior. Consistent with study predictions, use of the Web for information seeking interacted with respondents' desired level of uncertainty to predict their actual level of uncertainty about cancer prevention. The results offer evidence that respondents who used the Web to search for cancer information were better able than were respondents who did not seek information to achieve a level of uncertainty commensurate with the level of uncertainty they desired.

  1. Conductive Paper with Antibody-Like Film for Electrical Readings of Biomolecules

    Science.gov (United States)

    Tavares, Ana P. M.; Ferreira, Nádia S.; Truta, Liliana A. A. N. A.; Sales, M. Goreti F.

    2016-05-01

    This work reports a novel way of producing an inexpensive substrate support to assemble a sensing film, designed for the electrical transduction of an intended biomolecule. The support uses cellulose paper as substrate, made hydrophobic with solid wax and covered by a home-made conductive ink having graphite as core material. The hydrophobicity of the paper was confirmed by contact angle measurements and the conductive ink composition was optimized with regard to its adhesion, conductivity, and thermal stability. This support was further modified targeting its application in quantitative analysis. Carnitine (CRT) was selected as target compound, a cancer biomarker. The recognition material consisted of an antibody-like receptor film for CRT, tailored on the support and prepared by electrically-sustained polymerization of 3,4-ethylenedioxythiophene (EDOT) or dodecylbenzenesulfonic acid (DBS). Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy analysis confirmed the presence of the polymeric film on the support, and the performance of the devices was extensively evaluated with regard to linear response ranges, selectivity, applicability, and reusability. Overall, the paper-based sensors offer simplicity of fabrication, low cost and excellent reusability features. The design could also be extended to other applications in electrical-based approaches to be used in point-of-care (POC).

  2. [Novel Hyphenated Techniques of Atomic Spectrometry for Metal Species Interaction with Biomolecules].

    Science.gov (United States)

    Li, Yan; Yan, Xiu-ping

    2015-09-01

    Trace metals may be adopted by biological systems to assist in the syntheses and metabolic functions of genes (DNA and RNA) and proteins in the environment. These metals may be beneficial or may pose a risk to humans and other life forms. Novel hybrid techniques are required for studies on the interaction between different metal species and biomolecules, which is significant for biology, biochemistry, nutrition, agriculture, medicine, pharmacy, and environmental science. In recent years, our group dwells on new hyphenated techniques based on capillary electrophoresis (CE), electrothermal atomic absorption spectrometry (ETAAS), and inductively coupled plasma mass spectroscopy (ICP-MS), and their application for different metal species interaction with biomolecules such as DNA, HSA, and GSH. The CE-ETAAS assay and CE-ICP-MS assay allow sensitively probing the level of biomolecules such as DNA damage by different metal species and extracting the kinetic and thermodynamic information on the interactions of different metal species with biomolecules, provides direct evidences for the formation of different metal species--biomolecule adducts. In addition, the consequent structural information were extracted from circular dichroism (CD) and X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and Fourier transform infrared (FTIR) spectroscopy. The present works represent the most complete and extensive study to date on the interactions between different metal species with biomolecules, and also provide new evidences for and insights into the interactions of different metal species with biomolecules for further understanding of the toxicological effects of metal species.

  3. Comprehensive spectroscopic studies on the interaction of biomolecules with surfactant detached multi-walled carbon nanotubes.

    Science.gov (United States)

    Sekar, Gajalakshmi; Mukherjee, Amitava; Chandrasekaran, Natarajan

    2015-04-01

    This paper investigates the interaction of ten diverse biomolecules with surfactant detached Multi-Walled Carbon Nanotubes (MWCNTs) using multiple spectroscopic methods. Declining fluorescence intensity of biomolecules in combination with the hyperchromic effect in UV-Visible spectra confirmed the existence of the ground state complex formation. Quenching mechanism remains static and non-fluorescent. 3D spectral data of biomolecules suggested the possibilities of disturbances to the aromatic microenvironment of tryptophan and tyrosine residues arising out of CNTs interaction. Amide band Shifts corresponding to the secondary structure of biomolecules were observed in the of FTIR and FT-Raman spectra. In addition, there exists an increased Raman intensity of tryptophan residues of biomolecules upon interaction with CNTs. Hence, the binding of the aromatic structures of CNTs with the aromatic amino acid residues, in a particular, tryptophan was evidenced. Far UV Circular spectra have showed the loss of alpha-helical contents in biomolecules upon interaction with CNTs. Near UV CD spectra confirmed the alterations in the tryptophan positions of the peptide backbone. Hence, our results have demonstrated that the interaction of biomolecules with OH-MWCNTs would involve binding cum structural changes and alteration to their aromatic micro-environment.

  4. Biomolecule-recognition gating membrane using biomolecular cross-linking and polymer phase transition.

    Science.gov (United States)

    Kuroki, Hidenori; Ito, Taichi; Ohashi, Hidenori; Tamaki, Takanori; Yamaguchi, Takeo

    2011-12-15

    We present for the first time a biomolecule-recognition gating system that responds to small signals of biomolecules by the cooperation of biorecognition cross-linking and polymer phase transition in nanosized pores. The biomolecule-recognition gating membrane immobilizes the stimuli-responsive polymer, including the biomolecule-recognition receptor, onto the pore surface of a porous membrane. The pore state (open/closed) of this gating membrane depends on the formation of specific biorecognition cross-linking in the pores: a specific biomolecule having multibinding sites can be recognized by several receptors and acts as the cross-linker of the grafted polymer, whereas a nonspecific molecule cannot. The pore state can be distinguished by a volume phase transition of the grafted polymer. In the present study, the principle of the proposed system is demonstrated using poly(N-isopropylacrylamide) as the stimuli-responsive polymer and avidin-biotin as a multibindable biomolecule-specific receptor. As a result of the selective response to the specific biomolecule, a clear permeability change of an order of magnitude was achieved. The principle is versatile and can be applied to many combinations of multibindable analyte-specific receptors, including antibody-antigen and lectin-sugar analogues. The new gating system can find wide application in the bioanalytical field and aid the design of novel biodevices.

  5. Electrochemical immobilization of biomolecules on gold surface modified with monolayered L-cysteine

    Energy Technology Data Exchange (ETDEWEB)

    Honda, Mitsunori, E-mail: honda.mitsunori@jaea.go.jp; Baba, Yuji; Sekiguchi, Tetsuhiro; Shimoyama, Iwao; Hirao, Norie

    2014-04-01

    Immobilization of organic molecules on the top of a metal surface is not easy because of lattice mismatch between organic and metal crystals. Gold atoms bind to thiol groups through strong chemical bonds, and a self-assembled monolayer of sulfur-terminated organic molecules is formed on the gold surface. Herein, we suggested that a monolayer of L-cysteine deposited on a gold surface can act as a buffer layer to immobilize biomolecules on the metal surface. We selected lactic acid as the immobilized biomolecule because it is one of the simplest carboxyl-containing biomolecules. The immobilization of lactic acid on the metal surface was carried out by an electrochemical method in an aqueous environment under the potential range varying from − 0.6 to + 0.8 V. The surface chemical states before and after the electrochemical reaction were characterized using X-ray photoelectron spectroscopy (XPS). The N 1s and C 1s XPS spectra showed that the L-cysteine-modified gold surface can immobilize lactic acid via peptide bonds. This technique might enable the immobilization of large organic molecules and biomolecules. - Highlights: • Monolayer l-cysteine deposited on Au surface as a buffer layer to immobilize biomolecules. • Lactic acid as the immobilized biomolecule as it is simple carboxyl-containing biomolecule. • X-ray photoelectron spectroscopy (XPS) of surface chemical states, before and after. • L-cysteine-modified Au surface can immobilize lactic acid via peptide bonds.

  6. Formation of simple biomolecules from alanine in ocean by impacts

    Science.gov (United States)

    Umeda, Y.; Sekine, T.; Furukawa, Y.; Kakegawa, T.; Kobayashi, T.

    2013-12-01

    The biomolecules on the Earth are thought either to have originated from the extraterrestrial parts carried with flying meteorites or to have been formed from the inorganic materials on the Earth through given energy. From the standpoint to address the importance of impact energy, it is required to simulate experimentally the chemical reactions during impacts, because violent impacts may have occurred 3.8-4.0 Gyr ago to create biomolecules initially. It has been demonstrated that shock reactions among ocean (H2O), atmospheric nitrogen, and meteoritic constitution (Fe) can induce locally reduction environment to form simple bioorganic molecules such as ammonia and amino acid (Nakazawa et al., 2005; Furukawa et al., 2009). We need to know possible processes for alanine how chemical reactions proceed during repeated impacts and how complicated biomolecules are formed. Alanine can be formed from glycine (Umeda et al., in preparation). In this study, we carried out shock recovery experiments at pressures of 4.4-5.7 GPa to investigate the chemical reactions of alanine. Experiments were carried out with a propellant gun. Stainless steel containers (30 mm in diameter, 30 mm long) with 13C-labeled alanine aqueous solution immersed in olivine or hematite powders were used as targets. Air gap was present in the sample room (18 mm in diameter, 2 mm thick) behind the sample. The powder, solution, and air represent meteorite, ocean, and atmosphere on early Earth, respectively. Two powders of olivine and hematite help to keep the oxygen fugacity low and high during experiments, respectively in order to investigate the effect of oxygen fugacity on chemical processes of alanine. The recovered containers, after cleaned completely, were immersed into liquid nitrogen to freeze sample solution and then we drilled on the impact surface to extract water-soluble run products using pure water. Thus obtained products were analyzed by LC/MS for four amino acids (glycine, alanine, valine, and

  7. A TiS2 nanosheet enhanced fluorescence polarization biosensor for ultra-sensitive detection of biomolecules

    Science.gov (United States)

    Li, Xiang; Ding, Xuelian; Li, Yongfang; Wang, Linsong; Fan, Jing

    2016-05-01

    Development of new strategies for the sensitive and selective detection of ultra-low concentrations of specific cancer markers is of great importance for assessing cancer therapeutics due to its crucial role in early clinical diagnoses and biomedical applications. In this work, we have developed two types of fluorescence polarization (FP) amplification assay strategies for the detection of biomolecules by using TiS2 as a FP enhancer and Zn2+-dependent self-hydrolyzing deoxyribozymes as catalysts to realize enzyme-catalyzed target-recycling signal amplification. One approach is based on the terminal protection of small-molecule-linked DNA, in which biomolecular binding to small molecules in DNA-small-molecule chimeras can protect the conjugated DNA from degradation by exonuclease I (Exo I); the other approach is based on the terminal protection of biomolecular bound aptamer DNA, in which biomolecules directly bound to the single strand aptamer DNA can protect the ssDNA from degradation by Exo I. We select folate receptor (FR) and thrombin (Tb) as model analytes to verify the current concept. It is shown that under optimized conditions, our strategies exhibit high sensitivity and selectivity for the quantification of FR and Tb with low detection limits (0.003 ng mL-1 and 0.01 pM, respectively). Additionally, this strategy is a simple ``mix and detect'' approach, and does not require any separation steps. This biosensor is also utilized in the analysis of real biological samples, the results agree well with those obtained by the enzyme-linked immunosorbent assay (ELISA).Development of new strategies for the sensitive and selective detection of ultra-low concentrations of specific cancer markers is of great importance for assessing cancer therapeutics due to its crucial role in early clinical diagnoses and biomedical applications. In this work, we have developed two types of fluorescence polarization (FP) amplification assay strategies for the detection of biomolecules

  8. Laser-guided direct writing: a novel method to deposit biomolecules for biosensors arrays.

    Science.gov (United States)

    Xu, Juntao; Grant, Sheila A; Pastel, Robert L

    2003-01-01

    In this paper, we present a potential biomolecular patterning method, laser-guided direct writing guidance (LGDW), which may be utilized to deposit organic and bioactive particles for biosensor arrays. The instrumentation and operation of the LGDW system is introduced and the system settings used to achieve deposition are reported. The biomolecule, avidin, was deposited onto a substrate using LGDW to evaluate the possible damage from the laser on the biomolecules. The functionality of avidin after laser-based guidance was examined by exposing the deposited avidin molecules to its ligand, biotin. The results show some avidin retained its affinity to biotin after LGDW demonstrating little damage to the biomolecules.

  9. Biomolecule-directed assembly of binary gold and titanium dioxide nanoparticles.

    Science.gov (United States)

    Zhu, Xiaoli; Chen, Zhenyu; Zhang, Xin; Zhu, Zhiqiang; Li, Genxi

    2010-02-01

    We report in this paper a novel strategy for "bottom-up" assembly of two types of metallic and semiconductor nanoparticles. By only using a small biomolecule, coenzyme A, as a "linker" to direct the assembly of metallic gold and semiconductor titanium dioxide nanoparticles, the usual biomolecule-directed system can be greatly simplified. Effects of experimental conditions on the formation of binary nanoparticles are studied. This strategy using single small biomolecule to direct assembly of nanoparticles is proven to be efficient, facile and non-toxic and should be extendable to other building blocks.

  10. Financial Literacy, Confidence and Financial Advice Seeking

    NARCIS (Netherlands)

    Kramer, Marc M.

    2016-01-01

    We find that people with higher confidence in their own financial literacy are less likely to seek financial advice, but no relation between objective measures of literacy and advice seeking. The negative association between confidence and advice seeking is more pronounced among wealthy households.

  11. Si Nanopores Development for External Control of Transport of Biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Ileri, N; Tringe, J; Letant, S; Palozoglu, A; Stroeve, P; Faller, R

    2008-06-13

    Nazar Ileri has been involved in an independent, multidisciplinary effort to create a new class of molecular sieves for proteins and viruses. Her experimental work has been performed concurrently at two campuses, LLNL and UC Davis, while theoretical components have been largely accomplished at UC Davis. As will be described, the devices she is creating have great potential to improve very significantly the efficiency and selectivity of molecular transport over what is presently available from state-of-the-art membranes. Our biotechnology training program is based on an integrated study of the transport of biomolecules through conically-shaped, nanoporous silicon membranes. The overall objective of this effort is to demonstrate an efficient, highly selective membrane technology that is manufacturable for macroscopic areas and can be employed in sensing, diagnostic and biomedical applications. Our specific aims are to (1) fabricate and characterize the physical characteristics of the membranes, (2) to demonstrate their utility for molecular transport and separation, and (3) to develop models that will facilitate understanding of these devices as well as improved performance of the next generation of devices. We have proposed that the conical pores have superior performance characteristics compared to other porous filters. To study this hypothesis, complementary approaches from different disciplines, such as membrane synthesis, experiment, and molecular simulation need to be combined. This provides an ideal training environment for a future leader in biotechnology. Hence, for this study, Nazar Ileri has started to carry out a full range of experimental and theoretical investigations under our guidance. First, she has begun fabrication of filters with conical/pyramidal pores. She characterized the pores by AFM and SEM, and analyzed the images using wavelets and other mathematical tools. She has also started to conduct biomolecule transport experiments to compare the

  12. Tailoring GaN semiconductor surfaces with biomolecules.

    Science.gov (United States)

    Estephan, Elias; Larroque, Christian; Cuisinier, Frédéric J G; Bálint, Zoltán; Gergely, Csilla

    2008-07-24

    Functionalization of semiconductors constitutes a crucial step in using these materials for various electronic, photonic, biomedical, and sensing applications. Within the various possible approaches, selection of material-binding biomolecules from a random biological library, based on the natural recognition of proteins or peptides toward specific material, offers many advantages, most notably biocompatibility. Here we report on the selective functionalization of GaN, an important semiconductor that has found broad uses in the past decade due to its efficient electroluminescence and pronounced chemical stability. A 12-mer peptide ("GaN_probe") with specific recognition for GaN has evolved. The subtle interplay of mostly nonpolar hydrophobic and some polar amino acidic residues defines the high affinity adhesion properties of the peptide. The interaction forces between the peptide and GaN are quantified, and the hydrophobic domain of the GaN_probe is identified as primordial for the binding specificity. These nanosized binding blocks are further used for controlled placement of biotin-streptavidin complexes on the GaN surface. Thus, the controlled grow of a new, patterned inorganic-organic hybrid material is achieved. Tailoring of GaN by biological molecules can lead to a new class of nanostructured semiconductor-based devices.

  13. Polyacrylamide medium for the electrophoretic separation of biomolecules

    Science.gov (United States)

    Madabhushi, Ramakrishna S.; Gammon, Stuart A.

    2003-11-11

    A polyacryalmide medium for the electrophoretic separation of biomolecules. The polyacryalmide medium comprises high molecular weight polyacrylamides (PAAm) having a viscosity average molecular weight (M.sub.v) of about 675-725 kDa were synthesized by conventional red-ox polymerization technique. Using this separation medium, capillary electrophoresis of BigDye DNA sequencing standard was performed. A single base resolution of .about.725 bases was achieved in .about.60 minute in a non-covalently coated capillary of 50 .mu.m i.d., 40 cm effective length, and a filed of 160 V/cm at 40.degree. C. The resolution achieved with this formulation to separate DNA under identical conditions is much superior (725 bases vs. 625 bases) and faster (60 min. vs. 75 min.) to the commercially available PAAm, such as supplied by Amersham. The formulation method employed here to synthesize PAAm is straight-forward, simple and does not require cumbersome methods such as emulsion polymerizaiton in order to achieve very high molecular weights. Also, the formulation here does not require separation of PAAm from the reaction mixture prior to reconstituting the polymer to a final concentration. Furthermore, the formulation here is prepared from a single average mol. wt. PAAm as opposed to the mixture of two different average mo. wt. PAAm previously required to achieve high resolution.

  14. Interaction mechanism of biomolecules on vacancy defected 2D materials

    Science.gov (United States)

    Gürel, Hikmet Hakan; Salmankurt, Bahadır

    2017-02-01

    In this work, we present a first principles study of the adsorption of Adenine which is a nucleobases, Histide and Leucine molecules, which are the amino acids, on vacancy defected single layer materials such as graphene and phosphorene. Among these materials, graphene, which is a single layer honeycomb structure of carbon. Also, phosphorene is recently synthesized by mechanical exfoliation of the black phosphorus. Phosphorene forming a puckered honeycomb structure similar to silicene. However, unlike zero-bandgap graphene and silicene, phosphorene is a direct band gap semiconductor, which makes it very attractive for the nanoelectronic devices. According to the studies, local defects can always exist at any temperature. The most probable defect type is the single vacancy in the single layer honeycomb structures. Vacancy defects can be emerged during growth process and they change the properties of materials significantly. In this study, we show that how to manipulate interaction and binding mechanisms of biomolecules with 2D materials with increased chemical activity by vacancy defects.

  15. Interfacial water thickness at inorganic nanoconstructs and biomolecules: Size matters

    Energy Technology Data Exchange (ETDEWEB)

    Cardellini, Annalisa; Fasano, Matteo; Chiavazzo, Eliodoro; Asinari, Pietro, E-mail: pietro.asinari@polito.it

    2016-04-29

    Water molecules in the proximity of solid nanostructures influence both the overall properties of liquid and the structure and functionality of solid particles. The study of water dynamics at solid–liquid interfaces has strong implications in energy, environmental and biomedical fields. This article focuses on the hydration layer properties in the proximity of Carbon Nanotubes (CNTs) and biomolecules (proteins, polypeptides and amino acids). Here we show a quantitative relation between the solid surface extension and the characteristic length of water nanolayer (δ), which is confined at solid–liquid interfaces. Specifically, the size dependence is attributed to the limited superposition of nonbonded interactions in case of small molecules. These results may facilitate the design of novel energy or biomedical colloidal nanosuspensions, and a more fundamental understanding of biomolecular processes influenced by nanoscale water dynamics. - Highlights: • Properties of the water hydration layer are investigated. • New relation between extension of solid size and hydration layer established. • Possible impact on rational design of nanosuspensions.

  16. Regioselective Localization and Tracking of Biomolecules on Single Gold Nanoparticles.

    Science.gov (United States)

    Rajeeva, Bharath Bangalore; Hernandez, Derek S; Wang, Mingsong; Perillo, Evan; Lin, Linhan; Scarabelli, Leonardo; Pingali, Bharadwaj; Liz-Marzán, Luis M; Dunn, Andrew K; Shear, Jason B; Zheng, Yuebing

    2015-11-01

    Selective localization of biomolecules at the hot spots of a plasmonic nanoparticle is an attractive strategy to exploit the light-matter interaction due to the high field concentration. Current approaches for hot spot targeting are time-consuming and involve prior knowledge of the hot spots. Multiphoton plasmonic lithography is employed to rapidly immobilize bovine serum albumin (BSA) hydrogel at the hot spot tips of a single gold nanotriangle (AuNT). Regioselectivity and quantity control by manipulating the polarization and intensity of the incident laser are also established. Single AuNTs are tracked using dark-field scattering spectroscopy and scanning electron microscopy to characterize the regioselective process. Fluorescence lifetime measurements further confirm BSA immobilization on the AuNTs. Here, the AuNT-BSA hydrogel complexes, in conjunction with single-particle optical monitoring, can act as a framework for understanding light-molecule interactions at the subnanoparticle level and has potential applications in biophotonics, nanomedicine, and life sciences.

  17. GroPBS: Fast Solver for Implicit Electrostatics of Biomolecules

    Directory of Open Access Journals (Sweden)

    Franziska eBertelshofer

    2015-11-01

    Full Text Available Knowledge about the electrostatic potential on the surface of biomolecules or biomembranes under physiological conditions is an important step in the attempt to characterize the physico-chemical properties of these molecules and in particular also their interactions with each other. Additionally, knowledge about solution electrostatics may guide also the design of molecules with specified properties. However, explicit water models come at a high computational cost, rendering them unsuitable for large design studies or for docking purposes. Implicit models with the water phase treated as a continuum require the numerical solution of the Poisson-Boltzmann Equation (PBE. Here, we present a new flexible program for the numerical solution of the PBE, allowing for different geometries, and the explicit and implicit inclusion of membranes. It involves a discretization of space and the computation of the molecular surface. The PBE is solved using finite differences, the resulting set of equations is solved using a Gauss-Seidel method. It is shown for the example of the sucrose transporter ScrY that the implicit inclusion of a surrounding membrane has a strong effect also on the electrostatics within the pore region and thus need to be carefully considered e.g. in design studies on membrane proteins.

  18. Quantification of specific bindings of biomolecules by magnetorelaxometry

    Directory of Open Access Journals (Sweden)

    Steinhoff Uwe

    2008-03-01

    Full Text Available Abstract The binding reaction of the biomolecules streptavidin and anti-biotin antibody, both labelled by magnetic nanoparticles (MNP, to biotin coated on agarose beads, was quantified by magnetorelaxometry (MRX. Highly sensitive SQUID-based MRX revealed the immobilization of the MNP caused by the biotin-streptavidin coupling. We found that about 85% of streptavidin-functionalised MNP bound specifically to biotin-agarose beads. On the other hand only 20% of antibiotin-antibody functionalised MNP were specifically bound. Variation of the suspension medium revealed in comparison to phosphate buffer with 0.1% bovine serum albumin a slight change of the binding behaviour in human serum, probably due to the presence of functioning (non heated serum proteins. Furthermore, in human serum an additional non-specific binding occurs, being independent from the serum protein functionality. The presented homogeneous bead based assay is applicable in simple, uncoated vials and it enables the assessment of the binding kinetics in a volume without liquid flow. The estimated association rate constant for the MNP-labelled streptavidin is by about two orders of magnitude smaller than the value reported for free streptavidin. This is probably due to the relatively large size of the magnetic markers which reduces the diffusion of streptavidin. Furthermore, long time non-exponential kinetics were observed and interpreted as agglutination of the agarose beads.

  19. Microfluidic Droplet Dehydration for Concentrating Processes in Biomolecules

    Science.gov (United States)

    Anna, Shelley

    2014-03-01

    Droplets in microfluidic devices have proven useful as picoliter reactors for biochemical processing operations such as polymerase chain reaction, protein crystallization, and the study of enzyme kinetics. Although droplets are typically considered to be self-contained, constant volume reactors, there can be significant transport between the dispersed and continuous phases depending on solubility and other factors. In the present talk, we show that water droplets trapped within a microfluidic device for tens of hours slowly dehydrate, concentrating the contents encapsulated within. We use this slow dehydration along with control of the initial droplet composition to influence gellation, crystallization, and phase separation processes. By examining these concentrating processes in many trapped drops at once we gain insight into the stochastic nature of the events. In one example, we show that dehydration rate impacts the probability of forming a specific crystal habit in a crystallizing amino acid. In another example, we phase separate a common aqueous two-phase system within droplets and use the ensuing two phases to separate DNA from an initial mixture. We further influence wetting conditions between the two aqueous polymer phases and the continuous oil, promoting complete de-wetting and physical separation of the polymer phases. Thus, controlled dehydration of droplets allows for concentration, separation, and purification of important biomolecules on a chip.

  20. Diatom-based label-free optical biosensor for biomolecules.

    Science.gov (United States)

    Viji, S; Anbazhagi, M; Ponpandian, N; Mangalaraj, D; Jeyanthi, S; Santhanam, P; Devi, A Shenbaga; Viswanathan, C

    2014-10-01

    Diatoms are unicellular algae, which fabricates ornate biosilica shells called frustules that possess a surface rich in reactive silanol (Si-OH) groups. The intrinsic patterned porous structure of diatom frustules at nanoscale can be exploited in the effective detection of biomolecules. In this study, the frustules of a specific diatom Amphora sp. has been functionalized to detect bovine serum albumin (BSA). The functionalization of the diatom frustule substrate is achieved by using 3-aminopropyltriethoxysilane (APES). The field emission scanning electron microscopy (FESEM) results showed an ornately patterned surface of the frustule valve ordered at nanoscale. The Fourier transform infrared (FTIR) spectra confirmed the N-H bending and stretching of the amine group after amine functionalization. The emission peaks in the photoluminescence (PL) spectra of the amine-functionalized diatom biosilica selectively enhanced the intensity by a factor of ten when compared to that of a bare diatom biosilica. The result showed a significant quenching of PL intensity of BSA at around 445 nm due to the interaction of amine-functionalized diatom-BSA protein complex. The detection limit was found to be 3 × 10(-5) M of BSA protein. Hence, the study proves that the functionalized frustule of Amphora sp. is an effective quantitative analytical tool for optical label-free biosensing applications.

  1. Electron cross-sections and transport in liquids and biomolecules

    Science.gov (United States)

    White, Ronald; Casey, M.; Cocks, D.; Konvalov, D.; Brunger, M. J.; Garcia, G.; Petrovic, Z.; McEachran, R.; Buckman, S. J.; de Urquijo, J.

    2016-09-01

    Modelling of electron induced processes in plasma medicine and radiation damage is reliant on accurate self-consistent sets of cross-sections for electrons in tissue. These cross-sections (and associated transport theory) must accurately account not only the electron-biomolecule interactions but also for the soft-condensed nature of tissue. In this presentation, we report on recent swarm experiments for electrons in gaseous water and tetrahydrofuran using the pulsed-Townsend experiment, and the associated development of self-consistent cross-section sets that arise from them. We also report on the necessary modifications to gas-phase cross-sections required to accurately treat electron transport in liquids. These modifications involve the treatment of coherent scattering and screening of the electron interaction potential as well as the development of a new transport theory to accommodate these cross-sections. The accuracy of the ab-initio cross-sections is highlighted through comparison of theory and experiment for electrons in liquid argon and xenon.

  2. Two dimensional electron spin resonance: Structure and dynamics of biomolecules

    Science.gov (United States)

    Saxena, Sunil; Freed, Jack H.

    1998-03-01

    The potential of two dimensional (2D) electron spin resonance (ESR) for measuring the structural properties and slow dynamics of labeled biomolecules will be presented. Specifically, it will be shown how the recently developed method of double quantum (DQ) 2D ESR (S. Saxena and J. H. Freed, J. Chem. Phys. 107), 1317, (1997) can be used to measure large interelectron distances in bilabeled peptides. The need for DQ ESR spectroscopy, as well as the challenges and advantages of this method will be discussed. The elucidation of the slow reorientational dynamics of this peptide (S. Saxena and J. H. Freed, J. Phys. Chem. A, 101) 7998 (1997) in a glassy medium using COSY and 2D ELDOR ESR spectroscopy will be demonstrated. The contributions to the homogeneous relaxation time, T_2, from the overall and/or internal rotations of the nitroxide can be distinguished from the COSY spectrum. The growth of spectral diffusion cross-peaks^2 with mixing time in the 2D ELDOR spectra can be used to directly determine a correlation time from the experiment which can be related to the rotational correlation time.

  3. Engineered Carbon-Nanomaterial-Based Electrochemical Sensors for Biomolecules.

    Science.gov (United States)

    Tiwari, Jitendra N; Vij, Varun; Kemp, K Christian; Kim, Kwang S

    2016-01-26

    The study of electrochemical behavior of bioactive molecules has become one of the most rapidly developing scientific fields. Biotechnology and biomedical engineering fields have a vested interest in constructing more precise and accurate voltammetric/amperometric biosensors. One rapidly growing area of biosensor design involves incorporation of carbon-based nanomaterials in working electrodes, such as one-dimensional carbon nanotubes, two-dimensional graphene, and graphene oxide. In this review article, we give a brief overview describing the voltammetric techniques and how these techniques are applied in biosensing, as well as the details surrounding important biosensing concepts of sensitivity and limits of detection. Building on these important concepts, we show how the sensitivity and limit of detection can be tuned by including carbon-based nanomaterials in the fabrication of biosensors. The sensing of biomolecules including glucose, dopamine, proteins, enzymes, uric acid, DNA, RNA, and H2O2 traditionally employs enzymes in detection; however, these enzymes denature easily, and as such, enzymeless methods are highly desired. Here we draw an important distinction between enzymeless and enzyme-containing carbon-nanomaterial-based biosensors. The review ends with an outlook of future concepts that can be employed in biosensor fabrication, as well as limitations of already proposed materials and how such sensing can be enhanced. As such, this review can act as a roadmap to guide researchers toward concepts that can be employed in the design of next generation biosensors, while also highlighting the current advancements in the field.

  4. One-step 18F labeling of biomolecules using organotrifluoroborates

    Science.gov (United States)

    Liu, Zhibo; Lin, Kuo-Shyan; Bénard, François; Pourghiasian, Maral; Kiesewetter, Dale O; Perrin, David M; Chen, Xiaoyuan

    2017-01-01

    Herein we present a general protocol for the functionalization of biomolecules with an organotrifluoroborate moiety so that they can be radiolabeled with aqueous 18F fluoride (18F−) and used for positron emission tomography (PET) imaging. Among the β+-emitting radionuclides, fluorine-18 (18F) is the isotope of choice for PET, and it is produced, on-demand, in many hospitals worldwide. Organotrifluoroborates can be 18F-labeled in one step in aqueous conditions via 18F–19F isotope exchange. This protocol features a recently designed ammoniomethyltrifluoroborate, and it describes the following: (i) a synthetic strategy that affords modular synthesis of radiolabeling precursors via a copper-catalyzed ‘click’ reaction; and (ii) a one-step 18F-labeling method that obviates the need for HPLC purification. Within 30 min, 18F-labeled PET imaging probes, such as peptides, can be synthesized in good chemical and radiochemical purity (>98%), satisfactory radiochemical yield of 20–35% (n > 20, non-decay corrected) and high specific activity of 40–111 GBq/µmol (1.1–3.0 Ci/µmol). The entire procedure, including the precursor preparation and 18F radiolabeling, takes 7–10 d. PMID:26313478

  5. Radiation damage of biomolecules (RADAM) database development: current status

    Science.gov (United States)

    Denifl, S.; Garcia, G.; Huber, B. A.; Marinković, B. P.; Mason, N.; Postler, J.; Rabus, H.; Rixon, G.; Solov'yov, A. V.; Suraud, E.; Yakubovich, A. V.

    2013-06-01

    Ion beam therapy offers the possibility of excellent dose localization for treatment of malignant tumours, minimizing radiation damage in normal tissue, while maximizing cell killing within the tumour. However, as the underlying dependent physical, chemical and biological processes are too complex to treat them on a purely analytical level, most of our current and future understanding will rely on computer simulations, based on mathematical equations, algorithms and last, but not least, on the available atomic and molecular data. The viability of the simulated output and the success of any computer simulation will be determined by these data, which are treated as the input variables in each computer simulation performed. The radiation research community lacks a complete database for the cross sections of all the different processes involved in ion beam induced damage: ionization and excitation cross sections for ions with liquid water and biological molecules, all the possible electron - medium interactions, dielectric response data, electron attachment to biomolecules etc. In this paper we discuss current progress in the creation of such a database, outline the roadmap of the project and review plans for the exploitation of such a database in future simulations.

  6. Hybrid carbon nanomaterials for electrochemical detection of biomolecules

    Science.gov (United States)

    Laurila, Tomi

    2015-09-01

    Electrochemical detection of different biomolecules in vivo is a promising path towards in situ monitoring of human body and its functions. However, there are several major obstacles, such as sensitivity, selectivity and biocompatiblity, which must be tackled in order to achieve reliably and safely operating sensor devices. Here we show that by utilizing hybrid carbon materials as electrodes to detect two types of neurotransmitters, dopamine and glutamate, several advantages over commonly used electrode materials can be achieved. In particular, we will demonstrate here that it is possible to combine the properties of different carbon allotropes to obtain hybrid materials with greatly improved electrochemical performance. Three following examples of the approach are given: (i) diamond-like carbon (DLC) thin film electrodes with different layer thicknesses, (ii) multi-walled carbon nanotubes grown directly on top of DLC and (iii) carbon nanofibres synthesized on top of DLC thin films. Detailed structural and electrochemical characterization is carried out to rationalize the reasons behind the observed behvior. In addition, results from the atomistic simulations are utilized to obtain more information about the properties of the amorphous carbon thin films.

  7. Silver cluster-biomolecule hybrids: from basics towards sensors.

    Science.gov (United States)

    Bonačić-Koutecký, Vlasta; Kulesza, Alexander; Gell, Lars; Mitrić, Roland; Antoine, Rodolphe; Bertorelle, Franck; Hamouda, Ramzi; Rayane, Driss; Broyer, Michel; Tabarin, Thibault; Dugourd, Philippe

    2012-07-14

    We focus on the functional role of small silver clusters in model hybrid systems involving peptides in the context of a new generation of nanostructured materials for biosensing. The optical properties of hybrids in the gas phase and at support will be addressed with the aim to bridge fundamental and application aspects. We show that extension and enhancement of absorption of peptides can be achieved by small silver clusters due to the interaction of intense intracluster excitations with the π-π* excitations of chromophoric aminoacids. Moreover, we demonstrate that the binding of a peptide to a supported silver cluster can be detected by the optical fingerprint. This illustrates that supported silver clusters can serve as building blocks for biosensing materials. Moreover, the clusters can be used simultaneously to immobilize biomolecules and to increase the sensitivity of detection, thus replacing the standard use of organic dyes and providing label-free detection. Complementary to that, we show that protected silver clusters containing a cluster core and a shell liganded by thiolates exhibit absorption properties with intense transitions in the visible regime which are also suitable for biosensing applications.

  8. Morphological changes of calcite single crystals induced by graphene-biomolecule adducts

    Science.gov (United States)

    Calvaresi, Matteo; Di Giosia, Matteo; Ianiro, Alessandro; Valle, Francesco; Fermani, Simona; Polishchuk, Iryna; Pokroy, Boaz; Falini, Giuseppe

    2017-01-01

    Calcite has the capability to interact with a wide variety of molecules. This usually induces changes in shape and morphology of crystals. Here, this process was investigated using sheets of graphene-biomolecule adducts. They were prepared and made dispersible in water through the exfoliation of graphite by tip sonication in the presence tryptophan or N-acetyl-D-glucosamine. The crystallization of calcium carbonate in the presence of these additives was obtained by the vapor diffusion method and only calcite formed. The analysis of the microscopic observations showed that the graphene-biomolecule adducts affected shape and morphology of rhombohedral {10.4} faced calcite crystals, due to their stabilization of additional {hk.0} faces. The only presence of the biomolecule affected minimally shape and morphology of calcite crystals, highlighting the key role of the graphene sheets as 2D support for the adsorption of the biomolecules.

  9. Toward the Atomic-Level Mass Analysis of Biomolecules by the Scanning Atom Probe.

    Science.gov (United States)

    Nishikawa, Osamu; Taniguchi, Masahiro

    2016-12-22

    In 1994, a new type of atom probe instrument, named the scanning atom probe (SAP), was proposed. The unique feature of the SAP is the introduction of a small extraction electrode, which scans over a specimen surface and confines the high field, required for field evaporation of surface atoms in a small space, between the specimen and the electrode. Thus, the SAP does not require a sharp specimen tip. This indicates that the SAP can mass analyze the specimens which are difficult to form in a sharp tip, such as organic materials and biomolecules. Clean single wall carbon nanotubes (CNT), made by high-pressure carbon monoxide process are found to be the best substrates for biomolecules. Various amino acids and dipeptide biomolecules were successfully mass analyzed, revealing characteristic clusters formed by strongly bound atoms in the specimens. The mass analysis indicates that SAP analysis of biomolecules is not only qualitative, but also quantitative.

  10. Hard X-ray-induced optical luminescence via biomolecule-directed metal clusters.

    Science.gov (United States)

    Osakada, Yasuko; Pratx, Guillem; Sun, Conroy; Sakamoto, Masanori; Ahmad, Moiz; Volotskova, Olga; Ong, Qunxiang; Teranishi, Toshiharu; Harada, Yoshie; Xing, Lei; Cui, Bianxiao

    2014-04-07

    Here, we demonstrate that biomolecule-directed metal clusters are applicable in the study of hard X-ray excited optical luminescence, promising a new direction in the development of novel X-ray-activated imaging probes.

  11. Development of time-resolved laser-induced fluorescence spectroscopic technique for the analysis of biomolecules

    Directory of Open Access Journals (Sweden)

    Terzić M.

    2008-01-01

    Full Text Available Our developments of the time-resolved laser-induced fluorescence (TR-LIF detection system for biomolecules are presented. This system is based on the tunable (320 nm to 475 nm Nd:YAG laser pulses used to excite various biomolecules. The detection part is the Streak System for Fluorescence Lifetime Spectroscopy (Hamamatsu, Japan. The system consists of a C4334-01 streakscope, as a detector, DG 535 digital pulse/delay generator, C5094-S Spectrograph and HPD-TA System, as a temporal analyzer. The TR-LIF spectrometer is designed primarily to study the temperature and pressure effects on fluorescence behavior of biomolecules upon excitation with a single nanosecond pulse. The design of this system has capability to combine laser-induced breakdown (LIB with fluorescence, as well to study optodynamic behavior of fluorescence biomolecules.

  12. Biomolecule Sequencer: Nanopore Sequencing Technology for In-Situ Environmental Monitoring and Astrobiology

    Science.gov (United States)

    John, K. K.; Botkin, D. J.; Burton, A. S.; Castro-Wallace, S. L.; Chaput, J. D.; Dworkin, J. P.; Lupisella, M. L.; Mason, C. E.; Rubins, K. H.; Smith, D. J.; Stahl, S.; Switzer, C.

    2016-10-01

    Biomolecule Sequencer will demonstrate, for the first time, that DNA sequencing is feasible as a tool for in-situ environmental monitoring and astrobiology. A space-based sequencer could identify microbes, diseases, and help detect DNA-based life.

  13. Determination of the labeling density of fluorophore-biomolecule conjugates with absorption spectroscopy.

    Science.gov (United States)

    Grabolle, Markus; Brehm, Robert; Pauli, Jutta; Dees, Franziska M; Hilger, Ingrid; Resch-Genger, Ute

    2012-02-15

    Dye-biomolecule conjugation is frequently accompanied by considerable spectral changes of the dye's absorption spectrum that limit the use of the common photometrical method for the determination of labeling densities. Here, we describe an improvement of this method using the integral absorbance of the dye instead of its absorbance at the long wavelength maximum to determine the concentration of the biomolecule-coupled dye. This approach is illustrated for three different cyanine dyes conjugated to the antibody IgG.

  14. Recovery of biomolecules from marinated herring (Clupea harengus) brine using ultrafiltration through ceramic membranes

    DEFF Research Database (Denmark)

    Gringer, Nina; Hosseini, Seyed Vali; Svendsen, Tore;

    2015-01-01

    on recovery of high value biomolecules such as proteins, fatty acids, minerals, and phenolic compounds. Chemical and biological oxygen demand (COD, BOD5) as well as total suspended solids (TSS) were also measured to follow the performance of the ultrafiltration. The retentates contained 75-82% (95% TSS...... that ceramic ultrafiltration can recover biomolecules from marinated herring brines although pre-filtration optimization is still needed....

  15. Enhancing protease activity assay in droplet-based microfluidics using a biomolecule concentrator.

    Science.gov (United States)

    Chen, Chia-Hung; Sarkar, Aniruddh; Song, Yong-Ak; Miller, Miles A; Kim, Sung Jae; Griffith, Linda G; Lauffenburger, Douglas A; Han, Jongyoon

    2011-07-13

    We introduce an integrated microfluidic device consisting of a biomolecule concentrator and a microdroplet generator, which enhances the limited sensitivity of low-abundance enzyme assays by concentrating biomolecules before encapsulating them into droplet microreactors. We used this platform to detect ultralow levels of matrix metalloproteinases (MMPs) from diluted cellular supernatant and showed that it significantly (~10-fold) reduced the time required to complete the assay and the sample volume used.

  16. Plastic Trash goes Biohybrid"-Rapid and Selective Functionalization of Inert Plastic Surfaces with Biomolecules

    DEFF Research Database (Denmark)

    Schiller, Stefan M; Kambhampati, Dev; Stengel, Gudrun

    2010-01-01

    The covalent functionalization of "inert" polymers such as polypropylene with biomolecules for biocompatible or biosensor surfaces is challenging. Here we present a powerful approach to covalently modify "inert" macromolecular surfaces with biomacromolecules reusing old plastic material. A specia...... with a thin reactive plasma polymerized maleic anhydride nanolayer network, which can be subsequently modified with biomolecules for various applications, e.g., in tissue engineering and as biochips...

  17. Bio-NCs - the marriage of ultrasmall metal nanoclusters with biomolecules

    Science.gov (United States)

    Goswami, Nirmal; Zheng, Kaiyuan; Xie, Jianping

    2014-10-01

    Ultrasmall metal nanoclusters (NCs) have attracted increasing attention due to their fascinating physicochemical properties. Today, functional metal NCs are finding growing acceptance in biomedical applications. To achieve a better performance in biomedical applications, metal NCs can be interfaced with biomolecules, such as proteins, peptides, and DNA, to form a new class of biomolecule-NC composites (or bio-NCs in short), which typically show synergistic or novel physicochemical and physiological properties. This feature article focuses on the recent studies emerging at the interface of metal NCs and biomolecules, where the interactions could impart unique physicochemical properties to the metal NCs, as well as mutually regulate biological functions of the bio-NCs. In this article, we first provide a broad overview of key concepts and developments in the novel biomolecule-directed synthesis of metal NCs. A special focus is placed on the key roles of biomolecules in metal NC synthesis. In the second part, we describe how the encapsulated metal NCs affect the structure and function of biomolecules. Followed by that, we discuss several unique synergistic effects observed in the bio-NCs, and illustrate them with examples highlighting their potential biomedical applications. Continued interdisciplinary efforts are required to build up in-depth knowledge about the interfacial chemistry and biology of bio-NCs, which could further pave their ways toward biomedical applications.

  18. Desalting by crystallization: detection of attomole biomolecules in picoliter buffers by mass spectrometry.

    Science.gov (United States)

    Gong, Xiaoyun; Xiong, Xingchuang; Wang, Song; Li, Yanyan; Zhang, Sichun; Fang, Xiang; Zhang, Xinrong

    2015-10-06

    Sensitive detection of biomolecules in small-volume samples by mass spectrometry is, in many cases, challenging because of the use of buffers to maintain the biological activities of proteins and cells. Here, we report a highly effective desalting method for picoliter samples. It was based on the spontaneous separation of biomolecules from salts during crystallization of the salts. After desalting, the biomolecules were deposited in the tip of the quartz pipet because of the evaporation of the solvent. Subsequent detection of the separated biomolecules was achieved using solvent assisted electric field induced desorption/ionization (SAEFIDI) coupled with mass spectrometry. It allowed for direct desorption/ionization of the biomolecules in situ from the tip of the pipet. The organic component in the assistant solvent inhibited the desorption/ionization of salts, thus assured successful detection of biomolecules. Proteins and peptides down to 50 amol were successfully detected using our method even if there were 3 × 10(5) folds more amount of salts in the sample. The concentration and ion species of the salts had little influence on the detection results.

  19. Bio-NCs--the marriage of ultrasmall metal nanoclusters with biomolecules.

    Science.gov (United States)

    Goswami, Nirmal; Zheng, Kaiyuan; Xie, Jianping

    2014-11-21

    Ultrasmall metal nanoclusters (NCs) have attracted increasing attention due to their fascinating physicochemical properties. Today, functional metal NCs are finding growing acceptance in biomedical applications. To achieve a better performance in biomedical applications, metal NCs can be interfaced with biomolecules, such as proteins, peptides, and DNA, to form a new class of biomolecule-NC composites (or bio-NCs in short), which typically show synergistic or novel physicochemical and physiological properties. This feature article focuses on the recent studies emerging at the interface of metal NCs and biomolecules, where the interactions could impart unique physicochemical properties to the metal NCs, as well as mutually regulate biological functions of the bio-NCs. In this article, we first provide a broad overview of key concepts and developments in the novel biomolecule-directed synthesis of metal NCs. A special focus is placed on the key roles of biomolecules in metal NC synthesis. In the second part, we describe how the encapsulated metal NCs affect the structure and function of biomolecules. Followed by that, we discuss several unique synergistic effects observed in the bio-NCs, and illustrate them with examples highlighting their potential biomedical applications. Continued interdisciplinary efforts are required to build up in-depth knowledge about the interfacial chemistry and biology of bio-NCs, which could further pave their ways toward biomedical applications.

  20. Generating multiplex gradients of biomolecules for controlling cellular adhesion in parallel microfluidic channels.

    Science.gov (United States)

    Didar, Tohid Fatanat; Tabrizian, Maryam

    2012-11-07

    Here we present a microfluidic platform to generate multiplex gradients of biomolecules within parallel microfluidic channels, in which a range of multiplex concentration gradients with different profile shapes are simultaneously produced. Nonlinear polynomial gradients were also generated using this device. The gradient generation principle is based on implementing parrallel channels with each providing a different hydrodynamic resistance. The generated biomolecule gradients were then covalently functionalized onto the microchannel surfaces. Surface gradients along the channel width were a result of covalent attachments of biomolecules to the surface, which remained functional under high shear stresses (50 dyn/cm(2)). An IgG antibody conjugated to three different fluorescence dyes (FITC, Cy5 and Cy3) was used to demonstrate the resulting multiplex concentration gradients of biomolecules. The device enabled generation of gradients with up to three different biomolecules in each channel with varying concentration profiles. We were also able to produce 2-dimensional gradients in which biomolecules were distributed along the length and width of the channel. To demonstrate the applicability of the developed design, three different multiplex concentration gradients of REDV and KRSR peptides were patterned along the width of three parallel channels and adhesion of primary human umbilical vein endothelial cell (HUVEC) in each channel was subsequently investigated using a single chip.

  1. Recent advances in exploiting ionic liquids for biomolecules: Solubility, stability and applications.

    Science.gov (United States)

    Sivapragasam, Magaret; Moniruzzaman, Muhammad; Goto, Masahiro

    2016-08-01

    The technological utility of biomolecules (e.g. proteins, enzymes and DNA) can be significantly enhanced by combining them with ionic liquids (ILs) - potentially attractive "green" and "designer" solvents - rather than using in conventional organic solvents or water. In recent years, ILs have been used as solvents, cosolvents, and reagents for biocatalysis, biotransformation, protein preservation and stabilization, DNA solubilization and stabilization, and other biomolecule-based applications. Using ILs can dramatically enhance the structural and chemical stability of proteins, DNA, and enzymes. This article reviews the recent technological developments of ILs in protein-, enzyme-, and DNA-based applications. We discuss the different routes to increase biomolecule stability and activity in ILs, and the design of biomolecule-friendly ILs that can dissolve biomolecules with minimum alteration to their structure. This information will be helpful to design IL-based processes in biotechnology and the biological sciences that can serve as novel and selective processes for enzymatic reactions, protein and DNA stability, and other biomolecule-based applications.

  2. Cell and biomolecule delivery for tissue repair and regeneration in the central nervous system.

    Science.gov (United States)

    Elliott Donaghue, Irja; Tam, Roger; Sefton, Michael V; Shoichet, Molly S

    2014-09-28

    Tissue engineering frequently involves cells and scaffolds to replace damaged or diseased tissue. It originated, in part, as a means of effecting the delivery of biomolecules such as insulin or neurotrophic factors, given that cells are constitutive producers of such therapeutic agents. Thus cell delivery is intrinsic to tissue engineering. Controlled release of biomolecules is also an important tool for enabling cell delivery since the biomolecules can enable cell engraftment, modulate inflammatory response or otherwise benefit the behavior of the delivered cells. We describe advances in cell and biomolecule delivery for tissue regeneration, with emphasis on the central nervous system (CNS). In the first section, the focus is on encapsulated cell therapy. In the second section, the focus is on biomolecule delivery in polymeric nano/microspheres and hydrogels for the nerve regeneration and endogenous cell stimulation. In the third section, the focus is on combination strategies of neural stem/progenitor cell or mesenchymal stem cell and biomolecule delivery for tissue regeneration and repair. In each section, the challenges and potential solutions associated with delivery to the CNS are highlighted.

  3. Polystyrene nanoparticles facilitate the internalization of impermeable biomolecules in non-tumour and tumour cells from colon epithelium

    Energy Technology Data Exchange (ETDEWEB)

    Cabeza, Laura [University of Granada, Department of Human Anatomy and Embryology, Institute of Biopathology and Regenerative Medicine (IBIMER) (Spain); Cano-Cortés, Victoria; Rodríguez, María J. [University of Granada, Department of Pharmaceutical and Organic Chemistry (Spain); Vélez, Celia; Melguizo, Consolación, E-mail: melguizo@ugr.es [University of Granada, Department of Human Anatomy and Embryology, Institute of Biopathology and Regenerative Medicine (IBIMER) (Spain); Sánchez-Martín, Rosario M., E-mail: rmsanchez@ugr.es [University of Granada, Department of Pharmaceutical and Organic Chemistry (Spain); Prados, Jose [University of Granada, Department of Human Anatomy and Embryology, Institute of Biopathology and Regenerative Medicine (IBIMER) (Spain)

    2015-01-15

    Advanced colon cancer has a poor prognosis due to the limited effectiveness of current chemotherapies. Treatment failures may be avoided by the utilization of nanoparticles, which can enhance the effects of antitumor drugs, reduce their side effects and increase their directionality. Polystyrene nanoparticles have shown high biocompatibility and appropriate physicochemical properties and may represent a novel and more effective approach against colon cancer. In the present study, polystyrene nanoparticles were synthesized and fluorescently labelled, analyzing their cell internalization, intracellular localization and capacity to release transported molecules in tumour and non-tumour human colon cell lines (T84 and CCD-18). Flow cytometry and fluorescence microscopy studies demonstrated that polystyrene nanoparticles are an effective vehicle for the intracellular delivery of small molecules into colon epithelium cells. The percentage cell uptake was around 100 % in both T84 and CCD-18 cell lines after only 24 h of exposure and was cell confluence-independent. The polystyrene nanoparticles showed no cytotoxicity in either colon cell line. It was found that small molecules can be efficiently delivered into colon cells by using a disulphide bridge as release strategy. Analysis of the influence of the functionalization of the polystyrene nanoparticles surface on the internalization efficiency revealed some morphological changes in these cells. These results demonstrate that polystyrene nanoparticles may improve the transport of biomolecules into colon cells which could have a potential application in chemotherapeutic treatment against colon cancer.

  4. Polystyrene nanoparticles facilitate the internalization of impermeable biomolecules in non-tumour and tumour cells from colon epithelium

    Science.gov (United States)

    Cabeza, Laura; Cano-Cortés, Victoria; Rodríguez, María J.; Vélez, Celia; Melguizo, Consolación; Sánchez-Martín, Rosario M.; Prados, Jose

    2015-01-01

    Advanced colon cancer has a poor prognosis due to the limited effectiveness of current chemotherapies. Treatment failures may be avoided by the utilization of nanoparticles, which can enhance the effects of antitumor drugs, reduce their side effects and increase their directionality. Polystyrene nanoparticles have shown high biocompatibility and appropriate physicochemical properties and may represent a novel and more effective approach against colon cancer. In the present study, polystyrene nanoparticles were synthesized and fluorescently labelled, analyzing their cell internalization, intracellular localization and capacity to release transported molecules in tumour and non-tumour human colon cell lines (T84 and CCD-18). Flow cytometry and fluorescence microscopy studies demonstrated that polystyrene nanoparticles are an effective vehicle for the intracellular delivery of small molecules into colon epithelium cells. The percentage cell uptake was around 100 % in both T84 and CCD-18 cell lines after only 24 h of exposure and was cell confluence-independent. The polystyrene nanoparticles showed no cytotoxicity in either colon cell line. It was found that small molecules can be efficiently delivered into colon cells by using a disulphide bridge as release strategy. Analysis of the influence of the functionalization of the polystyrene nanoparticles surface on the internalization efficiency revealed some morphological changes in these cells. These results demonstrate that polystyrene nanoparticles may improve the transport of biomolecules into colon cells which could have a potential application in chemotherapeutic treatment against colon cancer.

  5. Cancer

    Science.gov (United States)

    Cancer begins in your cells, which are the building blocks of your body. Normally, your body forms ... be benign or malignant. Benign tumors aren't cancer while malignant ones are. Cells from malignant tumors ...

  6. Selective chromogenic detection of thiol-containing biomolecules using carbonaceous nanospheres loaded with silver nanoparticles as carrier.

    Science.gov (United States)

    Hu, Bo; Zhao, Yang; Zhu, Hai-Zhou; Yu, Shu-Hong

    2011-04-26

    Thiol-containing biomolecules show strong affinity with noble metal nanostructures and could not only stably protect them but also control the self-assembly process of these special nanostructures. A highly selective and sensitive chromogenic detection method has been designed for the low and high molecular weight thiol-containing biomolecules, including cysteine, glutathione, dithiothreitol, and bovine serum albumin, using a new type of carbonaceous nanospheres loaded with silver nanoparticles (Ag NPs) as carrier. This strategy relies upon the place-exchange process between the reporter dyes on the surface of Ag NPs and the thiol groups of thiol-containing biomolecules. The concentration of biomolecules can be determined by monitoring with the fluorescence intensity of reporter dyes dispersed in solution. This new chromogenic assay method could selectively detect these biomolecules in the presence of various other amino acids and monosaccharides and even sensitively detect the thiol-containing biomolecules with different molecular weight, even including proteins.

  7. Dual functionalized graphene oxide serves as a carrier for delivering oligohistidine- and biotin-tagged biomolecules into cells.

    Science.gov (United States)

    Jana, Batakrishna; Mondal, Goutam; Biswas, Atanu; Chakraborty, Indrani; Saha, Abhijit; Kurkute, Prashant; Ghosh, Surajit

    2013-11-01

    A versatile method of dual chemical functionalization of graphene oxide (GO) with Tris-[nitrilotris(acetic acid)] (Tris-NTA) and biotin for cellular delivery of oligohistidine- and biotin-tagged biomolecules is reported. Orthogonally functionalized GO surfaces with Tris-NTA and biotin to obtain a dual-functionalized GO (DFGO) are prepared and characterized by various spectroscopic and microscopic techniques. Fluorescence microscopic images reveal that DFGO surfaces are capable of binding oligohistidine-tagged biomolecules/proteins and avidin/biotin-tagged biomolecules/proteins orthogonally. The DFGO nanoparticles are non-cytotoxic in nature and can deliver oligohistidine- and biotin-tagged biomolecules simultaneously into the cell.

  8. Exploring Older Adults' Health Information Seeking Behaviors

    Science.gov (United States)

    Manafo, Elizabeth; Wong, Sharon

    2012-01-01

    Objective: To explore older adults' (55-70 years) health information-seeking behaviors. Methods: Using a qualitative methodology, based on grounded theory, data were collected using in-depth interviews. Participants were community-living, older adults in Toronto, Canada who independently seek nutrition and health information. Interview transcripts…

  9. Professional e-government seeking behavior

    DEFF Research Database (Denmark)

    Jonasen, Tanja Svarre; Lykke, Marianne

    2013-01-01

    The present paper is concerned with professional e-government seeking behavior. With the digitalization of governments, expectations have been raised with regard to changes in the composition of employee work tasks. The purpose of our study is to determine whether these changes affect seeking...

  10. Design of Interfaces for Information Seeking.

    Science.gov (United States)

    Marchionini, Gary; Komlodi, Anita

    1998-01-01

    Examines the current state of user interface design for information seeking. Topics include technology push and interdisciplinarity; research and development; literature trends; user-centered interface design; information seeking in electronic environments; online information retrieval system interfaces; online public access catalog interfaces;…

  11. Information-Seeking Habits of Education Faculty

    Science.gov (United States)

    Rupp-Serrano, Karen; Robbins, Sarah

    2013-01-01

    This study explores the information-seeking behavior of academic education faculty from twenty large public research universities. The investigation includes an examination of how frequently education faculty seek or access information, how they stay up-to-date on current developments in the field and identify less recent journal literature, how…

  12. Constructing Optimal Coarse-Grained Sites of Huge Biomolecules by Fluctuation Maximization.

    Science.gov (United States)

    Li, Min; Zhang, John Zenghui; Xia, Fei

    2016-04-12

    Coarse-grained (CG) models are valuable tools for the study of functions of large biomolecules on large length and time scales. The definition of CG representations for huge biomolecules is always a formidable challenge. In this work, we propose a new method called fluctuation maximization coarse-graining (FM-CG) to construct the CG sites of biomolecules. The defined residual in FM-CG converges to a maximal value as the number of CG sites increases, allowing an optimal CG model to be rigorously defined on the basis of the maximum. More importantly, we developed a robust algorithm called stepwise local iterative optimization (SLIO) to accelerate the process of coarse-graining large biomolecules. By means of the efficient SLIO algorithm, the computational cost of coarse-graining large biomolecules is reduced to within the time scale of seconds, which is far lower than that of conventional simulated annealing. The coarse-graining of two huge systems, chaperonin GroEL and lengsin, indicates that our new methods can coarse-grain huge biomolecular systems with up to 10,000 residues within the time scale of minutes. The further parametrization of CG sites derived from FM-CG allows us to construct the corresponding CG models for studies of the functions of huge biomolecular systems.

  13. Immobilization of biomolecules on cysteamine-modified polyaniline film for highly sensitive biosensing.

    Science.gov (United States)

    Cai, Qi; Xu, Baojian; Ye, Lin; Di, Zengfeng; Zhang, Jishen; Jin, Qinghui; Zhao, Jianlong; Xue, Jian; Chen, Xianfeng

    2014-03-01

    We present a new cysteamine (CS)-modified polyaniline (PANI) film for highly efficient immobilization of biomolecules in biosensing technology. This electrochemical deposited PANI film treated with CS and glutaraldehyde could be employed as an excellent substrate for biomolecules immobilization. The parameters of PANI growth were optimized to obtain suitable surface morphology of films for biomolecules combination with the help of electron and atomic force microscopy. Cyclic voltammetry (CV) was utilized to illustrate the different electrochemical activities of each modified electrode. Due to the existence of sulfydryl group and amino group in CS, surface modification with CS was proven to reduce oxidized units on PANI film remarkably, as evidenced by both ATR-FTIR and Raman spectroscopy characterizations. Furthermore, bovine serum albumin (BSA) was used as the model protein to investigate the immobilization efficiency of biomolecules on the PANI film, comparative study using quartz crystal microbalance (QCM) showed that BSA immobilized on CS-modified PANI could be increased by at least 20% than that without CS-modified PANI in BSA solution with the concentration of 0.1-1mg/mL. The CS-modified PANI film would be significant for the immobilization and detection of biomolecules and especially promising in the application of immunosensor for ultrasensitive detection.

  14. Role of PAMAM-OH dendrimers against the fibrillation pathway of biomolecules.

    Science.gov (United States)

    Sekar, Gajalakshmi; Florance, Ida; Sivakumar, A; Mukherjee, Amitava; Chandrasekaran, Natarajan

    2016-12-01

    The binding behavior of nanoparticle with proteins determines its biocompatibility. This study reports the interaction of ten different biomolecules (proteins-BSA, HSA, haemoglobin, gamma globulin, transferrin and enzymes-hog and bacillus amylase, lysozyme from chicken and human and laccases from Tramates versicolor) with a surface group hydroxylated Poly AMido AMide dendrimer (PAMAM) of generation 5. The study has utilized various spectroscopic methods like UV-vis spectroscopy, Fluorescence emission, Synchronous, 3-D spectroscopy and Circular Dichroism to detect the binding induced structural changes in biomolecules that occur upon interaction with mounting concentration of the dendrimers. Aggregation of proteins results in the formation of amyloid fibrils causing several human diseases. In this study, fibrillar samples of all ten biomolecules formed in the absence and the presence of dendrimers were investigated with Congo Red absorbance and ThT Assay to detect fibril formation, Trp Emission and 3-D scan to evaluate the effect of fibrillation on aromatic environment of biomolecules, and CD spectroscopy to measure the conformational changes in a quantitative manner. These assays have generated useful information on the role of dendrimers in amyloid fibril formation of biomolecules. The outcomes of the study remain valuable in evaluating the biological safety of PAMAM-OH dendrimers for their biomedical application in vivo.

  15. Fabrication of biomolecules self-assembled on Au nanodot array for bioelectronic device.

    Science.gov (United States)

    Lee, Taek; Kumar, Ajay Yagati; Yoo, Si-Youl; Jung, Mi; Min, Junhong; Choi, Jeong-Woo

    2013-09-01

    In the present study, an nano-platform composed of Au nanodot arrays on which biomolecules could be self-assembled was developed and investigated for a stable bioelectronic device platform. Au nanodot pattern was fabricated using a nanoporous alumina template. Two different biomolecules, a cytochrome c and a single strand DNA (ssDNA), were immobilized on the Au nanodot arrays. Cytochorme c and single stranded DNA could be immobilized on the Au nanodot using the chemical linker 11-MUA and thiol-modification by covalent bonding, respectively. The atomic structure of the fabricated nano-platform device was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The electrical conductivity of biomolecules immobilized on the Au nanodot arrays was confirmed by scanning tunneling spectroscopy (STS). To investigate the activity of biomolecule-immobilized Au-nano dot array, the cyclic voltammetry was carried out. This proposed nano-platform device, which is composed of biomolecules, can be used for the construction of a novel bioelectronic device.

  16. Conditions to minimize soft single biomolecule deformation when imaging with atomic force microscopy.

    Science.gov (United States)

    Godon, Christian; Teulon, Jean-Marie; Odorico, Michael; Basset, Christian; Meillan, Matthieu; Vellutini, Luc; Chen, Shu-Wen W; Pellequer, Jean-Luc

    2016-12-23

    A recurrent interrogation when imaging soft biomolecules using atomic force microscopy (AFM) is the putative deformation of molecules leading to a bias in recording true topographical surfaces. Deformation of biomolecules comes from three sources: sample instability, adsorption to the imaging substrate, and crushing under tip pressure. To disentangle these causes, we measured the maximum height of a well-known biomolecule, the tobacco mosaic virus (TMV), under eight different experimental conditions positing that the maximum height value is a specific indicator of sample deformations. Six basic AFM experimental factors were tested: imaging in air (AIR) versus in liquid (LIQ), imaging with flat minerals (MICA) versus flat organic surfaces (self-assembled monolayers, SAM), and imaging forces with oscillating tapping mode (TAP) versus PeakForce tapping (PFT). The results show that the most critical parameter in accurately measuring the height of TMV in air is the substrate. In a liquid environment, regardless of the substrate, the most critical parameter is the imaging mode. Most importantly, the expected TMV height values were obtained with both imaging with the PeakForce tapping mode either in liquid or in air at the condition of using self-assembled monolayers as substrate. This study unambiguously explains previous poor results of imaging biomolecules on mica in air and suggests alternative methodologies for depositing soft biomolecules on well organized self-assembled monolayers.

  17. Different size biomolecules anchoring on porous silicon surface: fluorescence and reflectivity pores infiltration comparative studies

    Energy Technology Data Exchange (ETDEWEB)

    Giovannozzi, Andrea M.; Rossi, Andrea M. [National Institute for Metrological Research, Thermodynamic Division, Strada delle Cacce 91, 10135 Torino (Italy); Renacco, Chiara; Farano, Alessandro [Ribes Ricecrhe Srl, Via Lavoratori Vittime del Col du Mont 24, 11100 Aosta (Italy); Derosas, Manuela [Biodiversity Srl, Via Corfu 71, 25124 Brescia (Italy); Enrico, Emanuele [National Institute for Metrological Research, Electromagnetism Division, Strada delle Cacce 91, 10135 Torino (Italy)

    2011-06-15

    The performance of porous silicon optical based biosensors strongly depends on material nanomorphology, on biomolecules distribution inside the pores and on the ability to link sensing species to the pore walls. In this paper we studied the immobilization of biomolecules with different size, such as antibody anti aflatoxin (anti Aflatox Ab, {proportional_to}150 KDa), malate dehydrogenase (MDH, {proportional_to}36KDa) and metallothionein (MT, {proportional_to}6KDa) at different concentrations on mesoporous silicon samples ({proportional_to}15 nm pores diameter). Fluorescence measurements using FITC- labeled biomolecules and refractive index analysis based on reflectivity spectra have been employed together to detect the amount of proteins bound to the surface and to evaluate their diffusion inside the pores. Here we suggest that these two techniques should be used together to have a better understanding of what happens at the porous silicon surface. In fact, when pores dimensions are not perfectly tuned to the protein size a higher fluorescence signal doesn't often correspond to a higher biomolecules distribution inside the pores. When a too much higher concentration of biomolecule is anchored on the surface, steric crowd effects and repulsive interactions probably take over and hinder pores infiltration, inducing a small or absent shift in the fringe pattern even if a higher fluorescence signal is registered. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Seeking Medical Information Using Mobile Apps and the Internet: Are Family Caregivers Different from the General Public?

    Science.gov (United States)

    Kim, Hyunmin; Paige Powell, M; Bhuyan, Soumitra S; Bhuyan, Soumitra Sudip

    2017-03-01

    Family caregivers play an important role to care cancer patients since they exchange medical information with health care providers. However, relatively little is known about how family caregivers seek medical information using mobile apps and the Internet. We examined factors associated with medical information seeking by using mobile apps and the Internet among family caregivers and the general public using data from the 2014 Health Information National Trends Survey 4 Cycle 1. The study sample consisted of 2425 family caregivers and 1252 non-family caregivers (the general public). Guided by Comprehensive Model of Information Seeking (CMIS), we examined related factors' impact on two outcome variables for medical information seeking: mobile apps use and Internet use with multivariate logistic regression analyses. We found that online medical information seeking is different between family caregivers and the general public. Overall, the use of the Internet for medical information seeking is more common among family caregivers, while the use of mobile apps is less common among family caregivers compared with the general public. Married family caregivers were less likely to use mobile apps, while family caregivers who would trust cancer information were more likely to use the Internet for medical information seeking as compared to the general public. Medical information seeking behavior among family caregivers can be an important predictor of both their health and the health of their cancer patients. Future research should explore the low usage of mobile health applications among family caregiver population.

  19. A brain cancer pathway in clinical practice

    DEFF Research Database (Denmark)

    Laursen, Emilie Lund; Rasmussen, Birthe Krogh

    2012-01-01

    Danish healthcare seeks to improve cancer survival through improved diagnostics, rapid treatment and increased focus on cancer prevention and early help-seeking. In neuro-oncology, this has resulted in the Integrated Brain Cancer Pathway (IBCP). The paper explores how the pathway works...... in the initial phase in a clinical setting with emphasis on pathway criteria....

  20. Finding Semirigid Domains in Biomolecules by Clustering Pair-Distance Variations

    Directory of Open Access Journals (Sweden)

    Michael Kenn

    2014-01-01

    Full Text Available Dynamic variations in the distances between pairs of atoms are used for clustering subdomains of biomolecules. We draw on a well-known target function for clustering and first show mathematically that the assignment of atoms to clusters has to be crisp, not fuzzy, as hitherto assumed. This reduces the computational load of clustering drastically, and we demonstrate results for several biomolecules relevant in immunoinformatics. Results are evaluated regarding the number of clusters, cluster size, cluster stability, and the evolution of clusters over time. Crisp clustering lends itself as an efficient tool to locate semirigid domains in the simulation of biomolecules. Such domains seem crucial for an optimum performance of subsequent statistical analyses, aiming at detecting minute motional patterns related to antigen recognition and signal transduction.

  1. Radical Reactions in the Gas Phase: Recent Development and Application in Biomolecules

    Directory of Open Access Journals (Sweden)

    Yang Gao

    2014-01-01

    Full Text Available This review summarizes recent literature describing the use of gas phase radical reactions for structural characterization of complex biomolecules other than peptides. Specifically, chemical derivatization, in-source chemical reaction, and gas phase ion/ion reactions have been demonstrated as effective ways to generate radical precursor ions that yield structural informative fragments complementary to those from conventional collision-induced dissociation (CID. Radical driven dissociation has been applied to a variety of biomolecules including peptides, nucleic acids, carbohydrates, and phospholipids. The majority of the molecules discussed in this review see limited fragmentation from conventional CID, and the gas phase radical reactions open up completely new dissociation channels for these molecules and therefore yield high fidelity confirmation of the structures of the target molecules. Due to the extensively studied peptide fragmentation, this review focuses only on nonpeptide biomolecules such as nucleic acids, carbohydrates, and phospholipids.

  2. Benzophenone-based photochemical micropatterning of biomolecules to create model substrates and instructive biomaterials.

    Science.gov (United States)

    Turgeon, Aurora J; Harley, Brendan A; Bailey, Ryan C

    2014-01-01

    The extracellular matrix (ECM) is a dynamic and heterogeneous environment that controls many aspects of cell behavior. Not surprisingly, many different approaches have focused on creating model substrates that recapitulate the biomolecular, topographical, and mechanical properties of the ECM for in vitro studies of cell behavior. This chapter details a general, versatile method for the spatially controlled deposition of multiple biomolecules onto both planar and topographically complex support structures with micrometer resolution. This approach is based upon the well-understood photochemical UV crosslinking of benzophenone (BP) to solution-phase biomolecules. This is a molecularly general strategy that can be utilized to immobilize biomolecules onto any surface prefunctionalized with BP. Examples described herein include modification of planar and corrugated glass substrates as well as collagen-glycosaminoglycan biomaterials configured either as highly porous scaffolds or nonporous membranes with a variety of biomolecular targets, including proteins, glycoproteins, and carbohydrates.

  3. SERS imaging of cell-surface biomolecules metabolically labeled with bioorthogonal Raman reporters.

    Science.gov (United States)

    Xiao, Ming; Lin, Liang; Li, Zefan; Liu, Jie; Hong, Senlian; Li, Yaya; Zheng, Meiling; Duan, Xuanming; Chen, Xing

    2014-08-01

    Live imaging of biomolecules with high specificity and sensitivity as well as minimal perturbation is essential for studying cellular processes. Here, we report the development of a bioorthogonal surface-enhanced Raman scattering (SERS) imaging approach that exploits small Raman reporters for visualizing cell-surface biomolecules. The cells were cultured and imaged by SERS microscopy on arrays of Raman-enhancing nanoparticles coated on silicon wafers or glass slides. The Raman reporters including azides, alkynes, and carbondeuterium bonds are small in size and spectroscopically bioorthogonal (background-free). We demonstrated that various cell-surface biomolecules including proteins, glycans, and lipids were metabolically incorporated with the corresponding precursors bearing a Raman reporter and visualized by SERS microscopy. The coupling of SERS microscopy with bioorthogonal Raman reporters expands the capabilities of live-cell microscopy beyond the modalities of fluorescence and label-free imaging.

  4. Finding semirigid domains in biomolecules by clustering pair-distance variations.

    Science.gov (United States)

    Kenn, Michael; Ribarics, Reiner; Ilieva, Nevena; Schreiner, Wolfgang

    2014-01-01

    Dynamic variations in the distances between pairs of atoms are used for clustering subdomains of biomolecules. We draw on a well-known target function for clustering and first show mathematically that the assignment of atoms to clusters has to be crisp, not fuzzy, as hitherto assumed. This reduces the computational load of clustering drastically, and we demonstrate results for several biomolecules relevant in immunoinformatics. Results are evaluated regarding the number of clusters, cluster size, cluster stability, and the evolution of clusters over time. Crisp clustering lends itself as an efficient tool to locate semirigid domains in the simulation of biomolecules. Such domains seem crucial for an optimum performance of subsequent statistical analyses, aiming at detecting minute motional patterns related to antigen recognition and signal transduction.

  5. Detection of biomolecules and bioconjugates by monitoring rotated grating-coupled surface plasmon resonance

    CERN Document Server

    Szalai, Aniko; Somogyi, Aniko; Szenes, Andras; Banhelyi, Balazs; Csapo, Edit; Dekany, Imre; Csendes, Tibor; Csete, Maria

    2016-01-01

    Plasmonic biosensing chips were prepared by fabricating wavelength-scaled dielectric-metal interfacial gratings on thin polycarbonate films covered bimetal layers via two-beam interference laser lithography. Lysozyme (LYZ) biomolecules and gold nanoparticle (AuNP-LYZ) bioconjugates with 1:5 mass ratio were seeded onto the biochip surfaces. Surface plasmon resonance spectroscopy was performed before and after biomolecule seeding in a modified Kretschmann-arrangement by varying the azimuthal and polar angles to optimize the conditions for rotated grating-coupling. The shift of secondary and primary resonance peaks originating from rotated grating-coupling phenomenon was monitored to detect the biomolecule and bioconjugate adherence. Numerical calculations were performed to reproduce the measured reflectance spectra and the resonance peak shifts caused by different biocoverings. Comparison of measurements and calculations proved that monitoring the narrower secondary peaks under optimal rotated-grating coupling ...

  6. Phthalocyanine-Biomolecule Conjugated Photosensitizers for Targeted Photodynamic Therapy and Imaging.

    Science.gov (United States)

    Iqbal, Zafar; Chen, Jincan; Chen, Zhuo; Huang, Mingdong

    2015-01-01

    Photodynamic therapy (PDT) is now in clinical practice in many European and American countries as a minimally invasive therapeutic technique to treat oncologic malignancies and other nononcologic conditions. Phthalocyanines (Pcs) are gathering importance as effective photosensitizers in targeted PDT and imaging of tumors. The possibility of modification around the Pc macrocycle led the researchers to the synthesis of a diversity of photosensitizers with varied cell specificity, cellular internalization and localization, photodynamic cytotoxicity and excretion. Cellular targeting is the primary aspect of an ideal photosensitizer for targeting PDT. Therefore, Pcs have been structurally modified with a variety of biomolecules capable of recognizing the specific lesions. This review emphasizes the photocytotoxicity and the cellular uptakes of phthalocyanine photosensitizers conjugated with biomolecules including carbohydrates, nucleotides and protein constituents such as amino acids and peptides. In addition, the role of the Pc-biomolecule conjugates in imaging and antimicrobial chemotherapy has been discussed.

  7. Composite scaffold of poly(vinyl alcohol) and interfacial polyelectrolyte complexation fibers for controlled biomolecule delivery.

    Science.gov (United States)

    Cutiongco, Marie Francene A; Choo, Royden K T; Shen, Nathaniel J X; Chua, Bryan M X; Sju, Ervi; Choo, Amanda W L; Le Visage, Catherine; Yim, Evelyn K F

    2015-01-01

    Controlled delivery of hydrophilic proteins is an important therapeutic strategy. However, widely used methods for protein delivery suffer from low incorporation efficiency and loss of bioactivity. The versatile interfacial polyelectrolyte complexation (IPC) fibers have the capacity for precise spatiotemporal release and protection of protein, growth factor, and cell bioactivity. Yet its weak mechanical properties limit its application and translation into a viable clinical solution. To overcome this limitation, IPC fibers can be incorporated into polymeric scaffolds such as the biocompatible poly(vinyl alcohol) hydrogel (PVA). Therefore, we explored the use of a composite scaffold of PVA and IPC fibers for controlled biomolecule release. We first observed that the permeability of biomolecules through PVA films were dependent on molecular weight. Next, IPC fibers were incorporated in between layers of PVA to produce PVA-IPC composite scaffolds with different IPC fiber orientation. The composite scaffold demonstrated excellent mechanical properties and efficient biomolecule incorporation. The rate of biomolecule release from PVA-IPC composite grafts exhibited dependence on molecular weight, with lysozyme showing near-linear release for 1 month. Angiogenic factors were also incorporated into the PVA-IPC grafts, as a potential biomedical application of the composite graft. While vascular endothelial growth factor only showed a maximum cumulative release of 3%, the smaller PEGylated-QK peptide showed maximum release of 33%. Notably, the released angiogenic biomolecules induced endothelial cell activity thus indicating retention of bioactivity. We also observed lack of significant macrophage response against PVA-IPC grafts in a rabbit model. Showing permeability, mechanical strength, precise temporal growth factor release, and bioinertness, PVA-IPC fibers composite scaffolds are excellent scaffolds for controlled biomolecule delivery in soft tissue engineering.

  8. Composite scaffold of poly(vinyl alcohol and interfacial polyelectrolyte complexation fibers for controlled biomolecule delivery

    Directory of Open Access Journals (Sweden)

    Marie Francene Arnobit Cutiongco

    2015-02-01

    Full Text Available Controlled delivery of hydrophilic proteins is an important therapeutic strategy. However, widely used methods for protein delivery suffer from low incorporation efficiency and loss of bioactivity. The versatile interfacial polyelectrolyte complexation (IPC fibers have the capacity for precise spatiotemporal release and protection of protein, growth factor and cell bioactivity. Yet its weak mechanical properties limit its application and translation into a viable clinical solution. To overcome this limitation, IPC fibers can be incorporated into polymeric scaffolds such as the biocompatible poly(vinyl alcohol hydrogel (PVA. Therefore, we explored the use of a composite scaffold of PVA and IPC fibers for controlled biomolecule release. We first observed that the permeability of biomolecules through PVA films were dependent on molecular weight, with lysozyme showing near-linear release for 1 month. Next, IPC fibers were incorporated in between layers of PVA to produce PVA-IPC composite scaffolds with different IPC fiber orientation. The composite scaffold demonstrated excellent mechanical properties and efficient biomolecule incorporation. The rate of biomolecule release from PVA-IPC composite grafts exhibited dependence on molecular weight. Angiogenic factors were also incorporated into the PVA-IPC grafts, as a potential biomedical application of the composite graft. While vascular endothelial growth factor only showed a maximum cumulative release of 3%, the smaller PEGylated-QK peptide showed maximum release of 33%. Notably, the released angiogenic biomolecules induced endothelial cell metabolic activity thus indicating retention of bioactivity. We also observed lack of significant macrophage response against PVA-IPC grafts in a rabbit model. Showing permeability, mechanical strength, precise temporal growth factor release and bioinertness, PVA-IPC fibers composite scaffolds are excellent scaffolds for controlled biomolecule delivery in soft

  9. PID Tuning Using Extremum Seeking

    Energy Technology Data Exchange (ETDEWEB)

    Killingsworth, N; Krstic, M

    2005-11-15

    ]. This method is based on the performance of the closed-loop system during a step response experiment [10], [11]. In this article we present a method for optimizing the step response of a closed-loop system consisting of a PID controller and an unknown plant with a discrete version of extremum seeking (ES). Specifically, ES is used to minimize a cost function similar to that used in [10], [11], which quantifies the performance of the PID controller. ES, a non-model-based method, iteratively modifies the arguments (in this application the PID parameters) of a cost function so that the output of the cost function reaches a local minimum or local maximum. In the next section we apply ES to PID controller tuning. We illustrate this technique through simulations comparing the effectiveness of ES to other PID tuning methods. Next, we address the importance of the choice of cost function and consider the effect of controller saturation. Furthermore, we discuss the choice of ES tuning parameters. Finally, we offer some conclusions.

  10. Live-cell stimulated Raman scattering imaging of alkyne-tagged biomolecules.

    Science.gov (United States)

    Hong, Senlian; Chen, Tao; Zhu, Yuntao; Li, Ang; Huang, Yanyi; Chen, Xing

    2014-06-02

    Alkynes can be metabolically incorporated into biomolecules including nucleic acids, proteins, lipids, and glycans. In addition to the clickable chemical reactivity, alkynes possess a unique Raman scattering within the Raman-silent region of a cell. Coupling this spectroscopic signature with Raman microscopy yields a new imaging modality beyond fluorescence and label-free microscopies. The bioorthogonal Raman imaging of various biomolecules tagged with an alkyne by a state-of-the-art Raman imaging technique, stimulated Raman scattering (SRS) microscopy, is reported. This imaging method affords non-invasiveness, high sensitivity, and molecular specificity and therefore should find broad applications in live-cell imaging.

  11. Biomolecule-assisted synthesis of highly stable dispersions of water-soluble copper nanoparticles.

    Science.gov (United States)

    Xiong, Jing; Wu, Xue-dong; Xue, Qun-ji

    2013-01-15

    Water-soluble and highly stable dispersions of copper nanoparticles were obtained using a biomolecule-assisted synthetic method. Dopamine was utilized as both reducing and capping agent in aqueous medium. The successful formation of DA-stabilized copper particles was demonstrated by ultraviolet-visible spectroscopy (UV-Vis), transmission electron microscopy (TEM), Zeta potential measurement, and Fourier transform infrared spectroscopy (FT-IR). The mechanism of dopamine on the effective reduction and excellent stability of copper nanoparticles was also discussed. This facile biomolecule-assisted technique may provide a useful tool to synthesize other nanoparticles that have potential application in biotechnology.

  12. Study of interactions between cells and microbubbles in high speed centrifugation field for biomolecule delivery.

    Science.gov (United States)

    He, Chuan; Chen, Jie

    2014-01-01

    Biomolecule delivery has a very wide range of applications in biology and medicine. In this study, a microbubble based delivery method was developed. In a high centrifugation field, cells deform and collide with microbubbles to induce intracellular pathways on cell membranes. As a result, biomaterials can then easily enter cells. Experimental results show that this delivery method can achieve high delivery efficiency. Simulation results showed that cells with more deformed structure experienced higher strain on cell membranes than cells with less deformed structure. The models can help explain how centrifugation affects cell membrane permeability. By controlling cell morphology and its mechanical properties, high biomolecule delivery efficiency can be achieved.

  13. Stochastic Control Model on Rent Seeking

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A continuous-time stochastic model is constructed to analyze how to control rent seeking behaviors. Using the stochastic optimization methods based on the modern risky theory, a unique positive solution to the dynamic model is derived. The effects of preference-related parameters on the optimal control level of rent seeking are discussed, and some policy measures are given. The results show that there exists a unique solution to the stochastic dynamic model under some macroeconomic assumptions, and that raising public expenditure may have reverse effects on rent seeking in an underdeveloped or developed economic environment.

  14. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... to treatment Seeking Information About Your Prognosis Is a Personal Decision When you have cancer, you and ... how long she has to live. For Doctors, a Patient-Centered Approach View this video on YouTube. ...

  15. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... treatment Seeking Information About Your Prognosis Is a Personal Decision When you have cancer, you and your ... think they are too impersonal to be of value to you. It is up to you to ...

  16. Scanning Health Information Sources: Applying and Extending the Comprehensive Model of Information Seeking.

    Science.gov (United States)

    Ruppel, Erin K

    2016-01-01

    Information scanning, or attention to information via incidental or routine exposure or browsing, is relatively less understood than information seeking. To (a) provide a more theoretical understanding of information scanning and (b) extend existing information seeking theory to information scanning, the current study used data from the National Cancer Institute's Health Information National Trends Survey to examine cancer information scanning using the comprehensive model of information seeking (CMIS). Consistent with the CMIS, health-related factors were associated with the information-carrier factor of trust, and health-related factors and trust were associated with attention to information sources. Some of these associations differed between entertainment-oriented sources, information-oriented sources, and the Internet. The current findings provide a clearer picture of information scanning and suggest future avenues of research and practice using the CMIS.

  17. Sexual information seeking on web search engines.

    Science.gov (United States)

    Spink, Amanda; Koricich, Andrew; Jansen, B J; Cole, Charles

    2004-02-01

    Sexual information seeking is an important element within human information behavior. Seeking sexually related information on the Internet takes many forms and channels, including chat rooms discussions, accessing Websites or searching Web search engines for sexual materials. The study of sexual Web queries provides insight into sexually-related information-seeking behavior, of value to Web users and providers alike. We qualitatively analyzed queries from logs of 1,025,910 Alta Vista and AlltheWeb.com Web user queries from 2001. We compared the differences in sexually-related Web searching between Alta Vista and AlltheWeb.com users. Differences were found in session duration, query outcomes, and search term choices. Implications of the findings for sexual information seeking are discussed.

  18. Cancer

    Science.gov (United States)

    ... uses a surgical tool to remove the tumor.Mohs' surgery. Layers of cancer cells are removed one ... usually have not been approved by the U.S. Food and Drug Administration (FDA). The medicine may have ...

  19. Social Work with unaccompanied aylum seeking children

    DEFF Research Database (Denmark)

    Jensen, Niels Rosendal

    2010-01-01

    Review of "textbook" on social work with unaccompanied asyum seeking children. This book presents national and international research findings, case stories and interviews, is written on a high level and deserves a braod audience......Review of "textbook" on social work with unaccompanied asyum seeking children. This book presents national and international research findings, case stories and interviews, is written on a high level and deserves a braod audience...

  20. Rent seeking and the economics of corruption

    OpenAIRE

    Aidt, T.S.

    2016-01-01

    The paper studies the influence of Gordon Tullock (1967) and the rent-seeking literature more generally on the study of corruption. The theoretical corruption literature with its emphasis on principal-agent relationships within government and rent creation by corruption politicians has largely, but not entirely, overlooked that contestable rents encourage unproductive use of real resources in seeking these rents. As a consequence, the literature underestimates the value of corruption control ...

  1. The Influences of Immigration on Health Information Seeking Behaviors among Korean Americans and Native Koreans

    Science.gov (United States)

    Oh, Kyeung Mi; Zhou, Qiuping; Kreps, Gary; Kim, Wonsun

    2014-01-01

    Korean Americans (KAs) have low screening rates for cancer and are often not well informed about their chronic diseases. Reduced access to health-related information is one reason for gaps in knowledge and the widening health disparities among minority populations. However, little research exists about KAs' health information seeking behaviors.…

  2. Engineered collagen hydrogels for the sustained release of biomolecules and imaging agents: promoting the growth of human gingival cells.

    Science.gov (United States)

    Choi, Jonghoon; Park, Hoyoung; Kim, Taeho; Jeong, Yoon; Oh, Myoung Hwan; Hyeon, Taeghwan; Gilad, Assaf A; Lee, Kwan Hyi

    2014-01-01

    We present here the in vitro release profiles of either fluorescently labeled biomolecules or computed tomography contrast nanoagents from engineered collagen hydrogels under physiological conditions. The collagen constructs were designed as potential biocompatible inserts into wounded human gingiva. The collagen hydrogels were fabricated under a variety of conditions in order to optimize the release profile of biomolecules and nanoparticles for the desired duration and amount. The collagen constructs containing biomolecules/nanoconstructs were incubated under physiological conditions (ie, 37°C and 5% CO2) for 24 hours, and the release profile was tuned from 20% to 70% of initially loaded materials by varying the gelation conditions of the collagen constructs. The amounts of released biomolecules and nanoparticles were quantified respectively by measuring the intensity of fluorescence and X-ray scattering. The collagen hydrogel we fabricated may serve as an efficient platform for the controlled release of biomolecules and imaging agents in human gingiva to facilitate the regeneration of oral tissues.

  3. Controlling plasmon coupling in biomolecule-linked metal nanoparticle assemblies

    Science.gov (United States)

    Sebba, David S.

    Molecular control of plasmon coupling is investigated in biomolecule-linked nanoparticle assemblies in two-particle, small cluster, and extended network formats. The relationship between structure and optical properties is explored through comparison of measured spectra with simulated spectra calculated using structural models based upon measured structural parameters. A variety of techniques are used to characterize nanoparticle assemblies, including ensemble extinction and elastic scattering spectroscopy, single-assembly scattering spectroscopy, transmission electron microscopy, and dynamic light scattering. Initially, molecular control of plasmon coupling is investigated in ˜100 nm assemblies composed of 13 nm gold "satellite" particles tethered by duplex DNA to a 50 nm gold "core" particle. Comparison of core-satellite assemblies formed with duplex DNA tethers of varying length demonstrates that, while core-satellite separation is controlled by the number of base pairs in the DNA tether, structural properties such as core:satellite ratio and yield are independent of DNA tether length. Thus, plasmon coupling within these assemblies is determined by the number of base pairs in the duplex DNA tether; compact assemblies in which tethers are composed of fewer base pairs exhibit plasmon bands that are red-shifted relative to the bands of extended assemblies, indicating increased plasmon coupling in the compact assemblies. Subsequently, core-satellite assemblies are formed with reconfigurable DNA nanostructure tethers that modulate interparticle separation in response to a molecular stimulus. Assembly reconfiguration from a compact to an extended state results in blue-shifting of the assembly plasmon resonance, indicating reduced interparticle coupling and lengthening of the core-satellite tether. Comparison between measured and simulated spectra revealed a close correspondence and provided validation of the structural models that link assembly plasmonic properties

  4. Mesoporous silica nanoparticles as smart and safe devices for regulating blood biomolecule levels

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yan [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    Stimuli-responsive end-capped MSN materials are promising drug carriers that securely deliver a large payload of drug molecules without degradation or premature release. A general review of the recent progress in this field is presented, including a summary of a series of hard and soft caps for drug encapsulation and a variety of internal and external stimuli for controlled release of different therapeutics, a discussion of the biocompatibility of MSN both in vitro and in vivo, and a description of the sophisticated stimuli-responsive systems with novel capping agents and controlled release mechanism. The unique internal and external surfaces of MSN were utilized for the development of a glucose-responsive double delivery system end-capped with insulin. This unique system consists of functionalized MSNs capable of releasing insulin when the concentration of sugar in blood exceeds healthy levels. The insulin-free nanoparticles are then up taken by pancreatic cells, and release inside of them another biomolecule that stimulates the production of more insulin. The in vivo application of this system for the treatment of diabetes requires further understanding on the biological behaviors of these nanoparticles in blood vessels. The research presented in this dissertation demonstrated the size and surface effects on the interaction of MSNs with red blood cell membranes, and discovered how the surface of the nanoparticles can be modified to improve their compatibility with red blood cells and avoid their dangerous side effects. In order to optimize the properties of MSN for applying them as efficient intracellular drug carriers it is necessary to understand the factors that can regulate their internalization into and exocytosis out of the cells. The correlation between the particle morphology and aggregation of MSNs to the effectiveness of cellular uptake is discussed and compared with different cell lines. The differences in the degree of exocytosis of MSNs between

  5. Plasma-based surface modification of polystyrene microtiter plates for covalent immobilization of biomolecules.

    Science.gov (United States)

    North, Stella H; Lock, Evgeniya H; Cooper, Candace J; Franek, James B; Taitt, Chris R; Walton, Scott G

    2010-10-01

    In recent years, polymer surfaces have become increasingly popular for biomolecule attachment because of their relatively low cost and desirable bulk physicochemical characteristics. However, the chemical inertness of some polymer surfaces poses an obstacle to more expansive implementation of polymer materials in bioanalytical applications. We describe use of argon plasma to generate reactive hydroxyl moieties at the surface of polystyrene microtiter plates. The plates are then selectively functionalized with silanes and cross-linkers suitable for the covalent immobilization of biomolecules. This plasma-based method for microtiter plate functionalization was evaluated after each step by X-ray photoelectron spectroscopy, water contact angle analysis, atomic force microscopy, and bioimmobilization efficacy. We further demonstrate that the plasma treatment followed by silane derivatization supports direct, covalent immobilization of biomolecules on microtiter plates and thus overcomes challenging issues typically associated with simple physisorption. Importantly, biomolecules covalently immobilized onto microtiter plates using this plasma-based method retained functionality and demonstrated attachment efficiency comparable to commercial preactivated microtiter plates.

  6. Applying forces to elastic network models of large biomolecules using a haptic feedback device.

    Science.gov (United States)

    Stocks, M B; Laycock, S D; Hayward, S

    2011-03-01

    Elastic network models of biomolecules have proved to be relatively good at predicting global conformational changes particularly in large systems. Software that facilitates rapid and intuitive exploration of conformational change in elastic network models of large biomolecules in response to externally applied forces would therefore be of considerable use, particularly if the forces mimic those that arise in the interaction with a functional ligand. We have developed software that enables a user to apply forces to individual atoms of an elastic network model of a biomolecule through a haptic feedback device or a mouse. With a haptic feedback device the user feels the response to the applied force whilst seeing the biomolecule deform on the screen. Prior to the interactive session normal mode analysis is performed, or pre-calculated normal mode eigenvalues and eigenvectors are loaded. For large molecules this allows the memory and number of calculations to be reduced by employing the idea of the important subspace, a relatively small space of the first M lowest frequency normal mode eigenvectors within which a large proportion of the total fluctuation occurs. Using this approach it was possible to study GroEL on a standard PC as even though only 2.3% of the total number of eigenvectors could be used, they accounted for 50% of the total fluctuation. User testing has shown that the haptic version allows for much more rapid and intuitive exploration of the molecule than the mouse version.

  7. Comparison of various silica-based monoliths for the analysis of large biomolecules.

    Science.gov (United States)

    Vuignier, Karine; Fekete, Szabolcs; Carrupt, Pierre-Alain; Veuthey, Jean-Luc; Guillarme, Davy

    2013-07-01

    In the present study, three types of silica-based monoliths, i.e. the first and second generations of commercial silica monolithic columns and a wide-pore prototype monolith were compared for the analysis of large biomolecules. These molecules possess molecular weights between 1 and 66 kDa. The gradient kinetic performance of the first-generation monolith was lower than that of the second generation, for large biomolecules (>14 kDa) but very close with smaller ones (1.3-5.8 kDa). In contrast, the wide-pore prototype column was particularly attractive with proteins larger than 19 kDa (higher peak capacity). Among these three columns, the selectivity and retention remained quite similar but a possible larger number of accessible and charged residual silanols was noticed on the wide-pore prototype material, which led to unpredicted small changes in selectivity and slightly broader peaks than expected. The peak shapes attained with the addition of 0.1% formic acid in the mobile phase remained acceptable for MS coupling, particularly for biomolecules of less than 6 kDa. It was found that one of the major issues with all of these silica-based monoliths is the possible poor recovery of large biomolecules (principally with monoclonal antibody fragments of more than 25 kDa).

  8. Extracting the Shape and Size of Biomolecules Attached to a Surface as Suspended Discrete Nanoparticles.

    Science.gov (United States)

    Milioni, Dimitra; Tsortos, Achilleas; Velez, Marisela; Gizeli, Electra

    2017-03-22

    The ability to derive information on the conformation of surface attached biomolecules by using simple techniques such as biosensors is currently considered of great importance in the fields of surface science and nanotechnology. Here we present a nanoshape sensitive biosensor where a simple mathematical expression is used to relate acoustic measurements to the geometrical features of a surface-attached biomolecule. The underlying scientific principle is that the acoustic ratio (ΔD/ΔF) is a measure of the hydrodynamic volume of the attached entity, mathematically expressed by its intrinsic viscosity [η]. A methodology is presented in order to produce surfaces with discretely bound biomolecules where their native conformation is maintained. Using DNA anchors we attached a spherical protein (streptavidin) and a rod-shaped DNA (47bp) to a quartz crystal microbalance (QCM) device in a suspended way and predicted correctly through acoustic measurements their conformation, i.e., shape and length. The methodology can be widely applied to draw conclusions on the conformation of any biomolecule or nanoentity upon specific binding on the surface of an acoustic wave device.

  9. Applications of Oblique-Incidence Reflectivity Difference Method in Primary Study of Protein Biomolecules

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-Yan; LIANG Ru-Qiang; JIN Kui-Juan; L(U) Hui-Bin; ZHU Xiang-Dong; ZHOU Yue-Liang; RUAN Kang-Cheng; YANG Guo-Zhen

    2006-01-01

    @@ Oblique-incidence reftectivity difference (OI-RD) analysis is applied to detect the immunoglobulin-G and cytochrome biomolecules on standard glass substrates without fluorescence labelling. The OI-RD intensities not only depend on the protein structure, but also vary with the protein concentration. The results indicate that this method should have potential applications in detection of biochemical processes.

  10. Cellular Viscosity in Prokaryotes and Thermal Stability of Low Molecular Weight Biomolecules.

    Science.gov (United States)

    Cuecas, Alba; Cruces, Jorge; Galisteo-López, Juan F; Peng, Xiaojun; Gonzalez, Juan M

    2016-08-23

    Some low molecular weight biomolecules, i.e., NAD(P)H, are unstable at high temperatures. The use of these biomolecules by thermophilic microorganisms has been scarcely analyzed. Herein, NADH stability has been studied at different temperatures and viscosities. NADH decay increased at increasing temperatures. At increasing viscosities, NADH decay rates decreased. Thus, maintaining relatively high cellular viscosity in cells could result in increased stability of low molecular weight biomolecules (i.e., NADH) at high temperatures, unlike what was previously deduced from studies in diluted water solutions. Cellular viscosity was determined using a fluorescent molecular rotor in various prokaryotes covering the range from 10 to 100°C. Some mesophiles showed the capability of changing cellular viscosity depending on growth temperature. Thermophiles and extreme thermophiles presented a relatively high cellular viscosity, suggesting this strategy as a reasonable mechanism to thrive under these high temperatures. Results substantiate the capability of thermophiles and extreme thermophiles (growth range 50-80°C) to stabilize and use generally considered unstable, universal low molecular weight biomolecules. In addition, this study represents a first report, to our knowledge, on cellular viscosity measurements in prokaryotes and it shows the dependency of prokaryotic cellular viscosity on species and growth temperature.

  11. Probing the interactions between boronic acids and cis-diol-containing biomolecules by affinity capillary electrophoresis.

    Science.gov (United States)

    Lü, Chenchen; Li, Hengye; Wang, Heye; Liu, Zhen

    2013-02-19

    The affinity of boronic acids to cis-diol-containing biomolecules has found wide applications in many fields, such as sensing, separation, drug delivery, and functional materials. A sound understanding of the binding interactions will greatly facilitate exquisite applications of this chemistry. Although a few analytical tools have been available for the characterization of the interactions, these techniques are associated with some apparent drawbacks, so they are only applicable to a limited range of boronic acids and cis-diol-containing biomolecules. Therefore, a widely applicable method is still greatly needed. In this work, an affinity capillary electrophoresis (ACE) method was established and validated to probe the interactions between boronic acids and cis-diol-containing biomolecules. The method was proven to be applicable to almost all types of cis-diol-containing biomolecules and boronic acids. Based on this method, a quantitative, comparative study on the interactions between 14 boronic acids that have important potentials for application with 5 typical monosaccharides of biological importance was carried out. The findings provided new insights into boronate affinity interactions, particularly the relationship between the binding strength with the molecular structures of the binding species. Besides, effects of pH and temperature on the binding strength were also investigated. This method exhibited several significant advantages, including (1) possibility of simultaneous study of multiple interactions, (2) low requirement on the purity of the binding species, (3) wide applicability, and (4) high accuracy and precision.

  12. Systematic methods for defining coarse-grained maps in large biomolecules.

    Science.gov (United States)

    Zhang, Zhiyong

    2015-01-01

    Large biomolecules are involved in many important biological processes. It would be difficult to use large-scale atomistic molecular dynamics (MD) simulations to study the functional motions of these systems because of the computational expense. Therefore various coarse-grained (CG) approaches have attracted rapidly growing interest, which enable simulations of large biomolecules over longer effective timescales than all-atom MD simulations. The first issue in CG modeling is to construct CG maps from atomic structures. In this chapter, we review the recent development of a novel and systematic method for constructing CG representations of arbitrarily complex biomolecules, in order to preserve large-scale and functionally relevant essential dynamics (ED) at the CG level. In this ED-CG scheme, the essential dynamics can be characterized by principal component analysis (PCA) on a structural ensemble, or elastic network model (ENM) of a single atomic structure. Validation and applications of the method cover various biological systems, such as multi-domain proteins, protein complexes, and even biomolecular machines. The results demonstrate that the ED-CG method may serve as a very useful tool for identifying functional dynamics of large biomolecules at the CG level.

  13. Facile immobilization of biomolecules onto various surfaces using epoxide-containing antibiofouling polymers.

    Science.gov (United States)

    Sung, Daekyung; Park, Sangjin; Jon, Sangyong

    2012-03-06

    The surface modifications of plastic or glass substrate and the subsequent immobilization of biomolecules onto the surfaces has been a central feature of the fabrication of biochips. To this end, we designed and synthesized new epoxide-containing random copolymers that form stable polymer adlayers on plastic or glass surface and subsequently react with amine or sulfhydryl functional groups of biomolecules under aqueous conditions. Epoxide-containing random copolymers were synthesized by radical polymerization of three functional monomers: a monomer acting as an anchor to the surfaces, a PEG group for preventing nonspecific protein adsorption, and an epoxide group for conjugating to biomolecules. Polymer coating layers were facilely formed on cyclic olefin copolymer (COC) or glass substrate by simply dipping each substrate into a solution of each copolymer. The polymer-coated surfaces characterized by a contact angle analyzer and X-ray photoelectron spectroscopy (XPS) showed very low levels of nonspecific immunoglobulin G (IgG) adsorption compared to the uncoated bare surface (control). Using a microcontact printing (μCP) method, antibodies as representative biomolecules could be selectively attached onto the copolymers-coated glass or COC surface with high signal-to-noise ratios.

  14. Surface enhanced Raman spectroscopy detection of biomolecules using EBL fabricated nanostructured substrates.

    Science.gov (United States)

    Peters, Robert F; Gutierrez-Rivera, Luis; Dew, Steven K; Stepanova, Maria

    2015-03-20

    Fabrication and characterization of conjugate nano-biological systems interfacing metallic nanostructures on solid supports with immobilized biomolecules is reported. The entire sequence of relevant experimental steps is described, involving the fabrication of nanostructured substrates using electron beam lithography, immobilization of biomolecules on the substrates, and their characterization utilizing surface-enhanced Raman spectroscopy (SERS). Three different designs of nano-biological systems are employed, including protein A, glucose binding protein, and a dopamine binding DNA aptamer. In the latter two cases, the binding of respective ligands, D-glucose and dopamine, is also included. The three kinds of biomolecules are immobilized on nanostructured substrates by different methods, and the results of SERS imaging are reported. The capabilities of SERS to detect vibrational modes from surface-immobilized proteins, as well as to capture the protein-ligand and aptamer-ligand binding are demonstrated. The results also illustrate the influence of the surface nanostructure geometry, biomolecules immobilization strategy, Raman activity of the molecules and presence or absence of the ligand binding on the SERS spectra acquired.

  15. Preparation of Biomolecule Microstructures and Microarrays by Thiol–ene Photoimmobilization

    NARCIS (Netherlands)

    Weinrich, Dirk; Köhn, Maja; Jonkheijm, Pascal; Westerlind, Ulrika; Dehmelt, Leif; Engelkamp, Hans; Christianen, Peter C.M.; Kuhlmann, Jürgen; Maan, Jan C.; Nüsse, Dirk; Schröder, Hendrik; Wacker, Ron; Voges, Edgar; Breinbauer, Rolf; Kunz, Horst; Niemeyer, Christof M.; Waldmann, Herbert

    2010-01-01

    A mild, fast and flexible method for photoimmobilization of biomolecules based on the light-initiated thiol–ene reaction has been developed. After investigation and optimization of various surface materials, surface chemistries and reaction parameters, microstructures and microarrays of biotin, olig

  16. Nanocoating for biomolecule delivery using layer-by-layer self-assembly.

    Science.gov (United States)

    Keeney, M; Jiang, X Y; Yamane, M; Lee, M; Goodman, S; Yang, F

    2015-11-07

    Since its introduction in the early 1990s, layer-by-layer (LbL) self-assembly of films has been widely used in the fields of nanoelectronics, optics, sensors, surface coatings, and controlled drug delivery. The growth of this industry is propelled by the ease of film manufacture, low cost, mild assembly conditions, precise control of coating thickness, and versatility of coating materials. Despite the wealth of research on LbL for biomolecule delivery, clinical translation has been limited and slow. This review provides an overview of methods and mechanisms of loading biomolecules within LbL films and achieving controlled release. In particular, this review highlights recent advances in the development of LbL coatings for the delivery of different types of biomolecules including proteins, polypeptides, DNA, particles and viruses. To address the need for co-delivery of multiple types of biomolecules at different timing, we also review recent advances in incorporating compartmentalization into LbL assembly. Existing obstacles to clinical translation of LbL technologies and enabling technologies for future directions are also discussed.

  17. Prospects of biomolecule sequencing with the techniques of translocation through nanopores: A review

    Energy Technology Data Exchange (ETDEWEB)

    Nosik, V. L., E-mail: v-nosik@yandex.ru; Rudakova, E. B. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2013-11-15

    The interest in the functional properties of biomolecules in native solutions (in particular, their interaction with membranes) constantly increases with accumulation of data on the macromolecular structure, obtained by X-ray diffraction (with synchrotron radiation sources), nuclear magnetic resonance, and mass spectrometry; this interest is closely related to the development of new technologies of sequencing (i.e., determining the sequence of nucleotides in DNA biomolecule). One of the most promising 'physical' approaches to sequencing is the application of methods based on the use of nanochannels or nanopores, through which biomolecules pass in ionic solutions under an electric field applied. A nanopore provides spatial localization of molecules and makes it possible to detect a signal (electric, fluorescent, etc.) from an individual nucleotide. In view of the development of new high-intensity pulsed X-ray sources, the popularity of fluorescence analysis constantly increases. The existing methods for simulating the motion of biomolecules and interpreting their structure, sequencing techniques, and the prospects of further development of investigations in this field are discussed.

  18. The minimum amount of "matrix " needed for matrix-assisted pulsed laser deposition of biomolecules

    DEFF Research Database (Denmark)

    Tabetah, Marshall; Matei, Andreea; Constantinescu, Catalin;

    2014-01-01

    of coarse-grained molecular dynamics simulations are performed for a model lysozyme-water system, where the water serves the role of volatile "matrix" that drives the ejection of the biomolecules. The simulations reveal a remarkable ability of a small (5-10 wt %) amount of matrix to cause the ejection...

  19. Tapered Optical Fiber Sensor for Label-Free Detection of Biomolecules

    Directory of Open Access Journals (Sweden)

    Xingwei Wang

    2011-03-01

    Full Text Available This paper presents a fast, highly sensitive and low-cost tapered optical fiber biosensor that enables the label-free detection of biomolecules. The sensor takes advantage of the interference effect between the fiber’s first two propagation modes along the taper waist region. The biomolecules bonded on the taper surface were determined by demodulating the transmission spectrum phase shift. Because of the sharp spectrum fringe signals, as well as a relatively long biomolecule testing region, the sensor displayed a fast response and was highly sensitive. To better understand the influence of various biomolecules on the sensor, a numerical simulation that varied biolayer parameters such as thickness and refractive index was performed. The results showed that the spectrum fringe shift was obvious to be measured even when the biolayer was only nanometers thick. A microchannel chip was designed and fabricated for the protection of the sensor and biotesting. Microelectromechanical systems (MEMS fabrication techniques were used to precisely control the profile and depth of the microchannel on the silicon chip with an accuracy of 2 μm. A tapered optical fiber biosensor was fabricated and evaluated with an Immune globulin G (IgG antibody-antigen pair.

  20. IMPLICATIONS OF RELATIVISTIC CONFIGURATIONS AND BAND STRUCTURES IN THE PHYSICS OF BIO-MOLECULES AND SOLIDS

    DEFF Research Database (Denmark)

    Islam, M. Fhokrul; Bohr, Henrik; Malik, F. B.

    2008-01-01

    Beyond the second row of elements in the Mendeleev periodic table, the consideration of the relativistic effect is important in determining proper configurations of atoms and ions, in many cases. Many important quantities of interest in determining physical and chemical properties of matter...... factor in facilitating intersystem crossing in bio-molecules....

  1. Exploring the flexible chemistry of 4-fluoro-3-nitrophenyl azide for biomolecule immobilization and bioconjugation.

    Science.gov (United States)

    Kumar, Saroj; Kumar, Dileep; Ahirwar, Rajesh; Nahar, Pradip

    2016-10-01

    Bioconjugation and functionalization of polymer surfaces are two major tasks in materials chemistry which are accomplished using a variety of coupling agents. Immobilization of biomolecules onto polymer surfaces and the construction of bioconjugates are essential requirements of many biochemical assays and chemical syntheses. Different linkers with a variety of functional groups are used for these purposes. Among them, the benzophenones, aryldiazirines, and arylazides represent the most commonly used photolinker to produce the desired chemical linkage upon their photo-irradiation. In this review, we describe the versatile applications of 4-fluoro-3-nitrophenyl azide, one of the oldest photolinkers used for photoaffinity labeling in the late 1960s. Surprisingly, this photolinker, historically known as 1-fluoro-2-nitro-4-azidobenzene (FNAB), has remained unexplored for a long time because of apprehension that FNAB forms ring-expanded dehydroazepine as a major product and hence cannot activate an inert polymer. The first evidence of photochemical activation of an inert surface by FNAB through nitrene insertion reaction was reported in 2001, and the FNAB-activated surface was found to conjugate a biomolecule without any catalyst, reagent, or modification. FNAB has distinct advantages over perfluorophenyl azide derivatives, which are contemporary nitrene-generating photolinkers, because of its simple, single-step preparation and ease of thermochemical and photochemical reactions with versatile polymers and biomolecules. Covering these aspects, the present review highlights the flexible chemistry of FNAB and its applications in the field of surface engineering, immobilization of biomolecules such as antibodies, enzymes, cells, carbohydrates, oligonucleotides, and DNA aptamers, and rapid diagnostics. Graphical Abstract An overview of the FNAB-engineered activated polymer surfaces for covalent ligation of versatile biomolecules.

  2. Designing the nanoparticle-biomolecule interface for "targeting and therapeutic delivery".

    Science.gov (United States)

    Mahon, Eugene; Salvati, Anna; Baldelli Bombelli, Francesca; Lynch, Iseult; Dawson, Kenneth A

    2012-07-20

    The endogenous transport mechanisms which occur in living organisms have evolved to allow selective transport and processing operate on a scale of tens of nanometers. This presents the possibility of unprecedented access for engineered nanoscale materials to organs and sub-cellular locations, materials which may in principle be targeted to precise locations for diagnostic or therapeutic gain. For this reason, nano-architectures could represent a truly radical departure as delivery agents for drugs, genes and therapies to treat a host of diseases. Thus, for active targeting, unlike the case of small molecular drugs where molecular structure has evolved to promote higher physiochemical affinity to specific sites, one aims to exploit these energy dependant endogenous processes. Many active targeting strategies have been developed, but despite this truly remarkable potential, in applications they have met with mixed success to date. This situation may have more to do with our current understanding and integration of knowledge across disciplines, than any intrinsic limitation on the vision itself. In this review article we suggest that much more fundamental and detailed control of the nanoparticle-biomolecule interface is required for sustained and general success in this field. In the simplest manifestation, pristine nanoparticles in biological fluids act as a scaffold for biomolecules, which adsorb rapidly to the nanoparticles' surface, conferring a new biological identity to the nanoparticles. It is this nanoparticle-biomolecule interface that is 'read' and acted upon by the cellular machinery. Moreover, where targeting moieties are grafted onto nanoparticles, they may not retain their function as a result of poor orientation, and structural or conformational disruption. Further surface adsorption of biomolecules from the surrounding environment i.e. the formation of a biomolecule corona may also obscure specific surface recognition. To transfer the remarkable

  3. Preparation of supramolecular hydrogel-enzyme hybrids exhibiting biomolecule-responsive gel degradation.

    Science.gov (United States)

    Shigemitsu, Hajime; Fujisaku, Takahiro; Onogi, Shoji; Yoshii, Tatsuyuki; Ikeda, Masato; Hamachi, Itaru

    2016-09-01

    Hydrogelators are small, self-assembling molecules that form supramolecular nanofiber networks that exhibit unique dynamic properties. Development of supramolecular hydrogels that degrade in response to various biomolecules could potentially be used for applications in areas such as drug delivery and diagnostics. Here we provide a synthetic procedure for preparing redox-responsive supramolecular hydrogelators that are used to create hydrogels that degrade in response to oxidizing or reducing conditions. The synthesis takes ∼2-4 d, and it can potentially be carried out in parallel to prepare multiple hydrogelator candidates. This described solid-phase peptide synthesis protocol can be used to produce previously described hydrogelators or to construct a focused molecular library to efficiently discover and optimize new hydrogelators. In addition, we describe the preparation of redox-responsive supramolecular hydrogel-enzyme hybrids that are created by mixing aqueous solutions of hydrogelators and enzymes, which requires 2 h for completion. The resultant supramolecular hydrogel-enzyme hybrids exhibit gel degradation in response to various biomolecules, and can be rationally designed by connecting the chemical reactions of the hydrogelators with enzymatic reactions. Gel degradation in response to biomolecules as triggers occurs within a few hours. We also describe the preparation of hydrogel-enzyme hybrids arrayed on flat glass slides, enabling high-throughput analysis of biomolecules such as glucose, uric acid, lactate and so on by gel degradation, which is detectable by the naked eye. The protocol requires ∼6 h to prepare the hydrogel-enzyme hybrid array and to complete the biomolecule assay.

  4. Mechanisms of host seeking by parasitic nematodes.

    Science.gov (United States)

    Gang, Spencer S; Hallem, Elissa A

    2016-07-01

    The phylum Nematoda comprises a diverse group of roundworms that includes parasites of vertebrates, invertebrates, and plants. Human-parasitic nematodes infect more than one billion people worldwide and cause some of the most common neglected tropical diseases, particularly in low-resource countries [1]. Parasitic nematodes of livestock and crops result in billions of dollars in losses each year [1]. Many nematode infections are treatable with low-cost anthelmintic drugs, but repeated infections are common in endemic areas and drug resistance is a growing concern with increasing therapeutic and agricultural administration [1]. Many parasitic nematodes have an environmental infective larval stage that engages in host seeking, a process whereby the infective larvae use sensory cues to search for hosts. Host seeking is a complex behavior that involves multiple sensory modalities, including olfaction, gustation, thermosensation, and humidity sensation. As the initial step of the parasite-host interaction, host seeking could be a powerful target for preventative intervention. However, host-seeking behavior remains poorly understood. Here we review what is currently known about the host-seeking behaviors of different parasitic nematodes, including insect-parasitic nematodes, mammalian-parasitic nematodes, and plant-parasitic nematodes. We also discuss the neural bases of these behaviors.

  5. An anlaysis of engineers information seeking activity

    DEFF Research Database (Denmark)

    Cash, Philip; Stanković, Tino; Štorga, Mario

    2013-01-01

    Information seeking is an important part of the engineering design process. In this context the Internet has become a significant source of information, shaping the way engineers work and interact. Current work has focused on characterizing this activity in terms of total time allocated to differ...... complete, the visual network analysis is used to explore patterns of information seeking and other design activity. Based on the results, three clearly differentiated types of information seeking activity are identified and discussed.......Information seeking is an important part of the engineering design process. In this context the Internet has become a significant source of information, shaping the way engineers work and interact. Current work has focused on characterizing this activity in terms of total time allocated...... to different information sources or overall tasks, such as evaluating. However, these approaches do not give an understanding of how engineers information seeking affects their problem solving activity and ultimately their performance in the context of the design process. As such, a new approach is needed...

  6. Nanobiotechnology: an efficient approach to drug delivery of unstable biomolecules.

    Science.gov (United States)

    Amaral, A C; Felipe, M S S

    2013-11-01

    Biotechnology and nanotechnology are fields of science that can be applied together to solve a variety of biological issues. In the case of human health, biotechnology attempts to improve advances on the therapy against several diseases. Therapeutic peptides and proteins are promissory molecules for developing new medicines. Gene transfection and RNA interference have been considered important approaches for modern therapy to treat cancer and viral infections. However, because of their instability, these molecules alone cannot be used for in vivo application, since they are easily degraded or presenting a poor efficiency. Nanotechnology can contribute by the development of nanostructured delivery systems to increase the stability and potency of these molecules. Studies involving polymeric and magnetic nanoparticles, dendrimers, and carbon nanotubes have demonstrated a possibility to use these systems as vectors instead of the conventional viral ones, which present adverse effects, such as recombination and immunogenicity. This review presents some possibilities and strategies to efficiently delivery peptides, proteins, gene and RNA interference using nanotechnology approach.

  7. Light-induced immobilisation of biomolecules as an attractive alternative to microdroplet dispensing-based arraying technologies

    DEFF Research Database (Denmark)

    Crookshanks, Meg; Skovsen, Esben; Petersen, Maria Teresa Neves;

    2007-01-01

    The present work shows how UV ‘light-induced molecular immobilisation' (LIMI) of biomolecules onto thiol reactive surfaces can be used to make biosensors, without the need for traditional microdispensing technologies. Using ‘LIMI,' arrays of biomolecules can be created with a high degree...... to conventional array formats. The ultimate consequence of the LIMI is that it is possible to write complex protein patterns using bitmaps at high resolution onto substrates. Thus, LIMI of biomolecules provides a new technological platform for biomolecular immobilisation and the potential for replacing present...

  8. CANCER

    Directory of Open Access Journals (Sweden)

    N. Kavoussi

    1973-09-01

    Full Text Available There are many carcinogenetic elements in industry and it is for this reason that study and research concerning the effect of these materials is carried out on a national and international level. The establishment and growth of cancer are affected by different factors in two main areas:-1 The nature of the human or animal including sex, age, point and method of entry, fat metabolism, place of agglomeration of carcinogenetic material, amount of material absorbed by the body and the immunity of the body.2 The different nature of the carcinogenetic material e.g. physical, chemical quality, degree of solvency in fat and purity of impurity of the element. As the development of cancer is dependent upon so many factors, it is extremely difficult to determine whether a causative element is principle or contributory. Some materials are not carcinogenetic when they are pure but become so when they combine with other elements. All of this creates an industrial health problem in that it is almost impossible to plan an adequate prevention and safety program. The body through its system of immunity protects itself against small amounts of carcinogens but when this amount increases and reaches a certain level the body is not longer able to defend itself. ILO advises an effective protection campaign against cancer based on the Well –equipped laboratories, Well-educated personnel, the establishment of industrial hygiene within factories, the regular control of safety systems, and the implementation of industrial health principles and research programs.

  9. Information Seeking in a Virtual Learning Environment.

    Science.gov (United States)

    Byron, Suzanne M.; Young, Jon I.

    2000-01-01

    Examines the applicability of Kuhlthau's Information Search Process Model in the context of a virtual learning environment at the University of North Texas that used virtual collaborative software. Highlights include cognitive and affective aspects of information seeking; computer experience and confidence; and implications for future research.…

  10. A Principle of Uncertainty for Information Seeking.

    Science.gov (United States)

    Kuhlthau, Carol C.

    1993-01-01

    Proposes an uncertainty principle for information seeking based on the results of a series of studies that investigated the user's perspective of the information search process. Constructivist theory is discussed as a conceptual framework for studying the user's perspective, and areas for further research are suggested. (Contains 44 references.)…

  11. Unaccompanied Asylum-Seeking Children: Whose Perspective?

    Science.gov (United States)

    Wernesjo, Ulrika

    2012-01-01

    Recent years have seen increasing attention being paid to unaccompanied asylum-seeking children. This article provides an overview of research in the field and its implications for an understanding of these children as a particularly vulnerable category. The existing research focuses primarily on investigating the children's emotional well-being…

  12. Rent seeking with efforts and bids

    NARCIS (Netherlands)

    Haan, M.A.; Schoonbeek, L.

    2003-01-01

    We introduce bids in a rent-seeking contest. Players compete for a prize. Apart from exerting lobbying efforts, they also submit a bid which is payable only if they win the prize. We show that our model has a unique Nash equilibrium in pure strategies, in which each active player submits the same bi

  13. Changing Attitudes toward Seeking Professional Help.

    Science.gov (United States)

    Chrisler, Joan C.

    Despite the increasing acceptance of the value of psychotherapy, there are still those who think people should solve their own problems. A study was conducted to investigate the attitudes of college students toward seeking professional help before and after taking a course in abnormal psychology to determine whether exposure to the purposes and…

  14. Leaders, laggards and technology seeking strategies

    NARCIS (Netherlands)

    Smeets, Roger; Bosker, E. M.

    2011-01-01

    We analyze the conditions determining optimal technology seeking strategies for leader and laggard firms. We extend existing theories by differentiating leaders and laggards in terms of absorptive capacity and intra-firm technology transfer skills, next to productivity levels. In addition, both Fore

  15. Interactive information seeking, behaviour and retrieval

    CERN Document Server

    Ruthven, Ian

    2011-01-01

    Information retrieval (IR) is a complex human activity supported by sophisticated systems. This book covers the whole spectrum of information retrieval, including: history and background information; behaviour and seeking task-based information; searching and retrieval approaches to investigating information; and, evaluation interfaces for IR.

  16. Multitasking Information Seeking and Searching Processes.

    Science.gov (United States)

    Spink, Amanda; Ozmutlu, H. Cenk; Ozmutlu, Seda

    2002-01-01

    Presents findings from four studies of the prevalence of multitasking information seeking and searching by Web (via the Excite search engine), information retrieval system (mediated online database searching), and academic library users. Highlights include human information coordinating behavior (HICB); and implications for models of information…

  17. Introducing “Seeking Truth in Love”

    Institute of Scientific and Technical Information of China (English)

    Theresa; Carino

    2006-01-01

    An excellent guide and commentary on Bishop KH Ting’s writings by scholars from Asia, Europe and North America, the bilingual volume Seeking Truth in Love"is now available at bookstores in China. Compiled and edited by Wang Peng,Dean of Studies at Nanjing Union Theological Seminary,the 393-page book was published in February,2006 by the Reli-

  18. Memory complaints associated with seeking clinical care

    NARCIS (Netherlands)

    Pires, C.; Silva, D.; Maroco, J.; Ginó, S.; Mendes, T.; Schmand, B.A.; Guerreiro, M.; de Mendonça, A.

    2012-01-01

    Diagnosis of mild cognitive impairment relies on the presence of memory complaints. However, memory complaints are very frequent in healthy people. The objective of this study was to determine the severity and type of memory difficulties presented by elderly patients who seek for clinical help, as c

  19. Memory Loss: When to Seek Help

    Science.gov (United States)

    Memory loss: When to seek help A number of conditions — not only Alzheimer's disease — can cause memory loss in older adults. Getting a prompt diagnosis ... a person you just met? Some degree of memory problems, as well as a modest decline in ...

  20. Assertiveness Training for Job-Seeking Skills

    Science.gov (United States)

    Ball, Patricia G.; McLoughlin, Mary Ellen

    1977-01-01

    Assertiveness Training for Job-Seeking Skills includes skill development in initiating the job search; arranging actual interviews; preparing a resume; articulating strengths, weaknesses, and career objectives; responding assertively in interviews; asking appropriate questions; accepting or rejecting job offers; confronting discrimination;…

  1. Information seeking behaviour of online museum visitors

    DEFF Research Database (Denmark)

    Skov, Mette

    two research projects on online museum visitors. The first case study will illustrate the information seeking and searching characteristics of online museum visitors at the National Museum of Military History in Copenhagen. Participants in this case study are characterised as special interest museum...

  2. Help Seeking in Online Collaborative Groupwork: A Multilevel Analysis

    Science.gov (United States)

    Du, Jianxia; Xu, Jianzhong; Fan, Xitao

    2015-01-01

    This study examined predictive models for students' help seeking in the context of online collaborative groupwork. Results from multilevel analysis revealed that most of the variance in help seeking was at the individual student level, and multiple variables at the individual level were predictive of help-seeking behaviour. Help seeking was…

  3. Leveraging zinc interstitials and oxygen vacancies for sensitive biomolecule detection through selective surface functionalization

    Science.gov (United States)

    Radha Shanmugam, Nandhinee; Muthukumar, Sriram; Chaudhry, Shajee; Prasad, Shalini

    2015-03-01

    In this study, functionally engineered EIS technique was implemented to investigate the influence of surface functionalization on sensitivity of biomolecule detection using nanostructured ZnO platform. Organic molecules with thiol and carboxylic functional groups were chosen to control biomolecule immobilization on zinc and oxygen-terminated 2D planar and 1D nanostructured ZnO surfaces. The amount of functionalization and its influence on charge perturbations at the ZnO-electrolyte interface were studied using fluorescence and EIS measurements. We observed the dependence of charge transfer on both the polarity of platform and concentration of cross-linker molecules. Such selectively modified surfaces were used for detection of cortisol, a major stress indicator. Results demonstrated preferential binding of thiol groups to Zn terminations and thus leveraging ZnO interstitials increases the sensitivity of detection over larger dynamic range with detection limit at 10fg/mL.

  4. Recent advances in chemical functionalization of nanoparticles with biomolecules for analytical applications.

    Science.gov (United States)

    Oh, Ju-Hwan; Park, Do Hyun; Joo, Jang Ho; Lee, Jae-Seung

    2015-11-01

    The recent synthetic development of a variety of nanoparticles has led to their widespread application in diagnostics and therapeutics. In particular, the controlled size and shape of nanoparticles precisely determine their unique chemical and physical properties, which is highly attractive for accurate analysis of given systems. In addition to efforts toward controlling the synthesis and properties of nanoparticles, the surface functionalization of nanoparticles with biomolecules has been intensively investigated since the mid-1990s. The complicated yet programmable properties of biomolecules have proved to substantially enhance and enrich the novel functions of nanoparticles to achieve "smart" nanoparticle materials. In this review, the advances in chemical functionalization of four types of representative nanoparticle with DNA and protein molecules in the past five years are critically reviewed, and their future trends are predicted.

  5. Probing nanoparticles and nanoparticle-conjugated biomolecules using time-of-flight secondary ion mass spectrometry.

    Science.gov (United States)

    Kim, Young-Pil; Shon, Hyun Kyong; Shin, Seung Koo; Lee, Tae Geol

    2015-01-01

    Bio-conjugated nanoparticles have emerged as novel molecular probes in nano-biotechnology and nanomedicine and chemical analyses of their surfaces have become challenges. The time-of-flight (TOF) secondary ion mass spectrometry (SIMS) has been one of the most powerful surface characterization techniques for both nanoparticles and biomolecules. When combined with various nanoparticle-based signal enhancing strategies, TOF-SIMS can probe the functionalization of nanoparticles as well as their locations and interactions in biological systems. Especially, nanoparticle-based SIMS is an attractive approach for label-free drug screening because signal-enhancing nanoparticles can be designed to directly measure the enzyme activity. The chemical-specific imaging analysis using SIMS is also well suited to screen nanoparticles and nanoparticle-biomolecule conjugates in complex environments. This review presents some recent applications of nanoparticle-based TOF-SIMS to the chemical analysis of complex biological systems.

  6. Heme biomolecule as redox mediator and oxygen shuttle for efficient charging of lithium-oxygen batteries

    Science.gov (United States)

    Ryu, Won-Hee; Gittleson, Forrest S.; Thomsen, Julianne M.; Li, Jinyang; Schwab, Mark J.; Brudvig, Gary W.; Taylor, André D.

    2016-10-01

    One of the greatest challenges with lithium-oxygen batteries involves identifying catalysts that facilitate the growth and evolution of cathode species on an oxygen electrode. Heterogeneous solid catalysts cannot adequately address the problematic overpotentials when the surfaces become passivated. However, there exists a class of biomolecules which have been designed by nature to guide complex solution-based oxygen chemistries. Here, we show that the heme molecule, a common porphyrin cofactor in blood, can function as a soluble redox catalyst and oxygen shuttle for efficient oxygen evolution in non-aqueous Li-O2 batteries. The heme's oxygen binding capability facilitates battery recharge by accepting and releasing dissociated oxygen species while benefiting charge transfer with the cathode. We reveal the chemical change of heme redox molecules where synergy exists with the electrolyte species. This study brings focus to the rational design of solution-based catalysts and suggests a sustainable cross-link between biomolecules and advanced energy storage.

  7. A review on recent developments for biomolecule separation at analytical scale using microfluidic devices.

    Science.gov (United States)

    Tetala, Kishore K R; Vijayalakshmi, M A

    2016-02-04

    Microfluidic devices with their inherent advantages like the ability to handle 10(-9) to 10(-18) L volume, multiplexing of microchannels, rapid analysis and on-chip detection are proving to be efficient systems in various fields of life sciences. This review highlights articles published since 2010 that reports the use of microfluidic devices to separate biomolecules (DNA, RNA and proteins) using chromatography principles (size, charge, hydrophobicity and affinity) along with microchip capillary electrophoresis, isotachophoresis etc. A detailed overview of stationary phase materials and the approaches to incorporate them within the microchannels of microchips is provided as well as a brief overview of chemical methods to immobilize ligand(s). Furthermore, we review research articles that deal with microfluidic devices as analytical tools for biomolecule (DNA, RNA and protein) separation.

  8. Tiny grains give huge gains: nanocrystal-based signal amplification for biomolecule detection.

    Science.gov (United States)

    Tong, Sheng; Ren, Binbin; Zheng, Zhilan; Shen, Han; Bao, Gang

    2013-06-25

    Nanocrystals, despite their tiny sizes, contain thousands to millions of atoms. Here we show that the large number of atoms packed in each metallic nanocrystal can provide a huge gain in signal amplification for biomolecule detection. We have devised a highly sensitive, linear amplification scheme by integrating the dissolution of bound nanocrystals and metal-induced stoichiometric chromogenesis, and demonstrated that signal amplification is fully defined by the size and atom density of nanocrystals, which can be optimized through well-controlled nanocrystal synthesis. Further, the rich library of chromogenic reactions allows implementation of this scheme in various assay formats, as demonstrated by the iron oxide nanoparticle linked immunosorbent assay (ILISA) and blotting assay developed in this study. Our results indicate that, owing to the inherent simplicity, high sensitivity and repeatability, the nanocrystal based amplification scheme can significantly improve biomolecule quantification in both laboratory research and clinical diagnostics. This novel method adds a new dimension to current nanoparticle-based bioassays.

  9. Immobilization of biomolecules onto surfaces according to ultraviolet light diffraction patterns

    DEFF Research Database (Denmark)

    Petersen, Steffen B.; Gennaro, Ane Kold Di; Neves Petersen, Teresa

    2010-01-01

    We developed a method for immobilization of biomolecules onto thiol functionalized surfaces according to UV diffraction patterns. UV light-assisted molecular immobilization proceeds through the formation of free, reactive thiol groups that can bind covalently to thiol reactive surfaces. We...... demonstrate that, by shaping the pattern of the UV light used to induce molecular immobilization, one can control the pattern of immobilized molecules onto the surface. Using a single-aperture spatial mask, combined with the Fourier transforming property of a focusing lens, we show that submicrometer (0.7 mu...... m) resolved patterns of immobilized prostate-specific antigen biomolecules can be created. If a dual-aperture spatial mask is used, the results differ from the expected Fourier transform pattern of the mask. It appears as a superposition of two diffraction patterns produced by the two apertures...

  10. Synthesis of new pyrrole-containing biomolecules as building blocks for functionalized polypyrroles in nanobiotechnology

    Energy Technology Data Exchange (ETDEWEB)

    Karsten, S; Liebscher, J [Department of Chemistry, Humboldt-Universitaet zu Berlin, Brook-Taylor-Str. 2, 12489 Berlin (Germany); Nan, A; Turcu, R, E-mail: sebastian.karsten@chemie.hu-berlin.d, E-mail: liebscher@chemie.hu-berlin.d [National Instiute of Research and Development for Isotopic and Molecular Technologies, Donath 65-103, RO-400293 Cluj-Napoca (Romania)

    2009-08-01

    New pyrroles were synthesized wherein biomolecules such as {alpha}-amino acids, peptides or carbohydrates are attached to position 1 or 3 via suitable linkers. These conjugates were copolymerized with pyrrole by chemical polymerisation alone giving corresponding copolymers or in the presence of magnetic iron oxid nanoparticles resulting in functionalized core-shell-nanoparticles. Such products are interesting for biosensing, imaging or separation of biomaterials. They were characterized by several methods such as TEM, HRTEM, FTIR and measuring of magnetization.

  11. Coherent diffraction and holographic imaging of individual biomolecules using low-energy electrons

    CERN Document Server

    Latychevskaia, Tatiana; Escher, Conrad; Fink, Hans-Werner

    2013-01-01

    Modern microscopy techniques are aimed at imaging an individual molecule at atomic resolution. Here we show that low-energy electrons with kinetic energies of 50-250 eV offer a possibility of overcome the problem of radiation damage, and obtaining images of individual biomolecules. Two experimental schemes for obtaining images of individual molecules, holography and coherent diffraction imaging, are discussed and compared. Images of individual molecules obtained by both techniques, using low-energy electrons, are shown.

  12. Submicron machining and biomolecule immobilization on porous silicon by electron beam.

    Science.gov (United States)

    Imbraguglio, Dario; Giovannozzi, Andrea Mario; Nastro, Annalisa; Rossi, Andrea Mario

    2012-09-25

    Three-dimensional submicrometric structures and biomolecular patterns have been fabricated on a porous silicon film by an electron beam-based functionalization method. The immobilized proteins act as a passivation layer against material corrosion in aqueous solutions. The effects' dependence on the main parameters of the process (i.e., the electron beam dose, the biomolecule concentration, and the incubation time) has been demonstrated.

  13. Strategies to balance covalent and non-covalent biomolecule attachment within collagen-GAG biomaterials.

    Science.gov (United States)

    Pence, Jacquelyn C; Gonnerman, Emily A; Bailey, Ryan C; Harley, Brendan A C

    2014-09-01

    Strategies to integrate instructive biomolecular signals into a biomaterial are becoming increasingly complex and bioinspired. While a large majority of reports still use repeated treatments with soluble factors, this approach can be prohibitively costly and difficult to translate in vivo for applications where spatial control over signal presentation is necessary. Recent efforts have explored the use of covalent immobilization of biomolecules to the biomaterial, via both bulk (ubiquitous) as well as spatially-selective light-based crosslinking, as a means to both enhance stability and bioactivity. However, little is known about how processing conditions during immobilization impact the degree of unintended non-covalent interactions, or fouling, that takes place between the biomaterial and the biomolecule of interest. Here we demonstrate the impact of processing conditions for bulk carbodiimide (EDC) and photolithography-based benzophenone (BP) crosslinking on specific attachment vs. fouling of a model protein (Concanavalin A, ConA) within collagen-glycosaminoglycan (CG) scaffolds. Collagen source significantly impacts the selectivity of biomolecule immobilization. EDC crosslinking intensity and ligand concentration significantly impacted selective immobilization. For benzophenone photoimmobilization we observed that increased UV exposure time leads to increased ConA immobilization. Immobilization efficiency for both EDC and BP strategies was maximal at physiological pH. Increasing ligand concentration during immobilization process led to enhanced immobilization for EDC chemistry, no impact on BP immobilization, but significant increases in non-specific fouling. Given recent efforts to covalently immobilize biomolecules to a biomaterial surface to enhance bioactivity, improved understanding of the impact of crosslinking conditions on selective attachment versus non-specific fouling will inform the design of instructive biomaterials for applications across tissue

  14. Cold-spray Ionization Mass Spectrometry for Characterization of Biomolecules in Solution

    Institute of Scientific and Technical Information of China (English)

    Kentaro YAMAGUCHI; Shigeru SAKAMOTO

    2003-01-01

    @@ A direct solution analysis method, coldspray ionization (CSI) mass spectrometry (MS)[1], a variant of electrospray (ESI) MS operating at low temperature (ca. - 80 ~ 10℃), allows facile and precise characterization of labile organic species, especially those in which non-covalent bonding interactions are prominent. We have applies this method to investigations of the solution structures of many labile organic species, including unstable reagents and reaction intermediates, asymmetric catalysts, supramolecules, and even primary biomolecules.

  15. Nanoshell-based substrates for surface enhanced spectroscopic detection of biomolecules.

    Science.gov (United States)

    Levin, Carly S; Kundu, Janardan; Barhoumi, Aoune; Halas, Naomi J

    2009-09-01

    Nanoshells are optically tunable core-shell nanostructures with demonstrated uses in surface enhanced spectroscopies. Based on their ability to support surface plasmons, which give rise to strongly enhanced electromagnetic fields at their surface, nanoshells provide simple, scalable, high-quality substrates. In this article, we outline the development and use of nanoshell-based substrates for direct, spectroscopic detection of biomolecules. Recent advances in the use of these nanostructures lead to improved spectroscopic quality, selectivity, and reproducibility.

  16. Mechanistic studies on the reactions of platinum(II) complexes with nitrogen- and sulfur-donor biomolecules.

    Science.gov (United States)

    Bugarčić, Živadin D; Bogojeski, Jovana; Petrović, Biljana; Hochreuther, Stephanie; van Eldik, Rudi

    2012-10-28

    A brief overview of mechanistic studies on the reactions of different Pt(II) complexes with nitrogen- and sulfur-donor biomolecules is presented. The first part describes the results obtained for substitution reactions of mono-functional Pt(II) complexes with different biomolecules, under various experimental conditions (temperature, pH and ionic strength). In addition, an overview of the results obtained for the substitution reactions of bi-functional Pt(II) complexes, analogous to cisplatin, with biomolecules is given. The last part of this report deals with different polynuclear Pt(II) complexes and their substitution behaviour with different biomolecules. The purpose of this perspective is to improve the understanding of the mechanism of action of Pt(II) complexes as potential anti-tumour drugs in the human body.

  17. Computational On-Chip Imaging of Nanoparticles and Biomolecules using Ultraviolet Light

    Science.gov (United States)

    Daloglu, Mustafa Ugur; Ray, Aniruddha; Gorocs, Zoltan; Xiong, Matthew; Malik, Ravinder; Bitan, Gal; McLeod, Euan; Ozcan, Aydogan

    2017-03-01

    Significant progress in characterization of nanoparticles and biomolecules was enabled by the development of advanced imaging equipment with extreme spatial-resolution and sensitivity. To perform some of these analyses outside of well-resourced laboratories, it is necessary to create robust and cost-effective alternatives to existing high-end laboratory-bound imaging and sensing equipment. Towards this aim, we have designed a holographic on-chip microscope operating at an ultraviolet illumination wavelength (UV) of 266 nm. The increased forward scattering from nanoscale objects at this short wavelength has enabled us to detect individual sub-30 nm nanoparticles over a large field-of-view of >16 mm2 using an on-chip imaging platform, where the sample is placed at ≤0.5 mm away from the active area of an opto-electronic sensor-array, without any lenses in between. The strong absorption of this UV wavelength by biomolecules including nucleic acids and proteins has further enabled high-contrast imaging of nanoscopic aggregates of biomolecules, e.g., of enzyme Cu/Zn-superoxide dismutase, abnormal aggregation of which is linked to amyotrophic lateral sclerosis (ALS) - a fatal neurodegenerative disease. This UV-based wide-field computational imaging platform could be valuable for numerous applications in biomedical sciences and environmental monitoring, including disease diagnostics, viral load measurements as well as air- and water-quality assessment.

  18. Recent trends in carbon nanomaterial-based electrochemical sensors for biomolecules: A review

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Cheng; Denno, Madelaine E.; Pyakurel, Poojan; Venton, B. Jill, E-mail: jventon@virginia.edu

    2015-08-05

    Carbon nanomaterials are advantageous for electrochemical sensors because they increase the electroactive surface area, enhance electron transfer, and promote adsorption of molecules. Carbon nanotubes (CNTs) have been incorporated into electrochemical sensors for biomolecules and strategies have included the traditional dip coating and drop casting methods, direct growth of CNTs on electrodes and the use of CNT fibers and yarns made exclusively of CNTs. Recent research has also focused on utilizing many new types of carbon nanomaterials beyond CNTs. Forms of graphene are now increasingly popular for sensors including reduced graphene oxide, carbon nanohorns, graphene nanofoams, graphene nanorods, and graphene nanoflowers. In this review, we compare different carbon nanomaterial strategies for creating electrochemical sensors for biomolecules. Analytes covered include neurotransmitters and neurochemicals, such as dopamine, ascorbic acid, and serotonin; hydrogen peroxide; proteins, such as biomarkers; and DNA. The review also addresses enzyme-based electrodes that are used to detect non-electroactive species such as glucose, alcohols, and proteins. Finally, we analyze some of the future directions for the field, pointing out gaps in fundamental understanding of electron transfer to carbon nanomaterials and the need for more practical implementation of sensors. - Highlights: • We review the types of carbon nanomaterials used in electrochemical sensors. • Different materials and sensor designs are compared for classes of biomolecules. • Future challenges of better sensor design and implementation are assessed.

  19. Measuring masses of large biomolecules and bioparticles using mass spectrometric techniques.

    Science.gov (United States)

    Peng, Wen-Ping; Chou, Szu-Wei; Patil, Avinash A

    2014-07-21

    Large biomolecules and bioparticles play a vital role in biology, chemistry, biomedical science and physics. Mass is a critical parameter for the characterization of large biomolecules and bioparticles. To achieve mass analysis, choosing a suitable ion source is the first step and the instruments for detecting ions, mass analyzers and detectors should also be considered. Abundant mass spectrometric techniques have been proposed to determine the masses of large biomolecules and bioparticles and these techniques can be divided into two categories. The first category measures the mass (or size) of intact particles, including single particle quadrupole ion trap mass spectrometry, cell mass spectrometry, charge detection mass spectrometry and differential mobility mass analysis; the second category aims to measure the mass and tandem mass of biomolecular ions, including quadrupole ion trap mass spectrometry, time-of-flight mass spectrometry, quadrupole orthogonal time-of-flight mass spectrometry and orbitrap mass spectrometry. Moreover, algorithms for the mass and stoichiometry assignment of electrospray mass spectra are developed to obtain accurate structure information and subunit combinations.

  20. Computational On-Chip Imaging of Nanoparticles and Biomolecules using Ultraviolet Light.

    Science.gov (United States)

    Daloglu, Mustafa Ugur; Ray, Aniruddha; Gorocs, Zoltan; Xiong, Matthew; Malik, Ravinder; Bitan, Gal; McLeod, Euan; Ozcan, Aydogan

    2017-03-09

    Significant progress in characterization of nanoparticles and biomolecules was enabled by the development of advanced imaging equipment with extreme spatial-resolution and sensitivity. To perform some of these analyses outside of well-resourced laboratories, it is necessary to create robust and cost-effective alternatives to existing high-end laboratory-bound imaging and sensing equipment. Towards this aim, we have designed a holographic on-chip microscope operating at an ultraviolet illumination wavelength (UV) of 266 nm. The increased forward scattering from nanoscale objects at this short wavelength has enabled us to detect individual sub-30 nm nanoparticles over a large field-of-view of >16 mm(2) using an on-chip imaging platform, where the sample is placed at ≤0.5 mm away from the active area of an opto-electronic sensor-array, without any lenses in between. The strong absorption of this UV wavelength by biomolecules including nucleic acids and proteins has further enabled high-contrast imaging of nanoscopic aggregates of biomolecules, e.g., of enzyme Cu/Zn-superoxide dismutase, abnormal aggregation of which is linked to amyotrophic lateral sclerosis (ALS) - a fatal neurodegenerative disease. This UV-based wide-field computational imaging platform could be valuable for numerous applications in biomedical sciences and environmental monitoring, including disease diagnostics, viral load measurements as well as air- and water-quality assessment.

  1. Graphene-Templated Synthesis of Magnetic Metal Organic Framework Nanocomposites for Selective Enrichment of Biomolecules.

    Science.gov (United States)

    Cheng, Gong; Wang, Zhi-Gang; Denagamage, Sachira; Zheng, Si-Yang

    2016-04-27

    Successful control of homogeneous and complete coating of graphene or graphene-based composites with well-defined metal organic framework (MOF) layers is a great challenge. Herein, novel magnetic graphene MOF composites were constructed via a simple strategy for self-assembly of well-distributed, dense, and highly porous MOFs on both sides of graphene nanosheets. Graphene functionalized with magnetic nanoparticles and carboxylic groups on both sides was explored as the backbone and template to direct the controllable self-assembly of MOFs. The prepared composite materials have a relatively high specific surface area (345.4 m(2) g(-1)), and their average pore size is measured to be 3.2 nm. Their relatively high saturation magnetization (23.8 emu g(-1)) indicates their strong magnetism at room temperature. Moreover, the multifunctional composite was demonstrated to be a highly effective affinity material in selective extraction and separation of low-concentration biomolecules from biological samples, in virtue of the size-selection property of the unique porous structure and the excellent affinity of the composite materials. Besides providing a solution for the construction of well-defined functional graphene-based MOFs, this work could also contribute to selective extraction of biomolecules, in virtue of the universal affinity between immobilized metal ions and biomolecules.

  2. Influence of reactive species on the modification of biomolecules generated from the soft plasma.

    Science.gov (United States)

    Attri, Pankaj; Kumar, Naresh; Park, Ji Hoon; Yadav, Dharmendra Kumar; Choi, Sooho; Uhm, Han S; Kim, In Tae; Choi, Eun Ha; Lee, Weontae

    2015-02-04

    Plasma medicine is an upcoming research area that has attracted the scientists to explore more deeply the utility of plasma. So, apart from the treating biomaterials and tissues with plasma, we have studied the effect of soft plasma with different feeding gases such as Air, N2 and Ar on modification of biomolecules. Hence, in this work we have used the soft plasma on biomolecules such as proteins ((Hemoglobin (Hb) and Myoglobin (Mb)), calf thymus DNA and amino acids. The structural changes or structural modification of proteins and DNA have been studied using circular dichroism (CD), fluorescence spectroscopy, protein oxidation test, gel electrophoresis, UV-vis spectroscopy, dynamic light scattering (DLS) and 1D NMR, while Liquid Chromatograph/Capillary Electrophoresis-Mass Spectrometer (LC/CE-MS) based on qualitative and quantitative bio-analysis have been used to study the modification of amino acids. Further, the thermal analysis of the protein has been studied with differential scanning calorimetry (DSC) and CD. Additionally, we have performed docking studies of H2O2 with Hb and Mb, which reveals that H2O2 molecules preferably attack the amino acids near heme group. We have also shown that N2 gas plasma has strong deformation action on biomolecules and compared to other gases plasma.

  3. [Probabilistic calculations of biomolecule charge states that generate mass spectra of multiply charged ions].

    Science.gov (United States)

    Raznikova, M O; Raznikov, V V

    2015-01-01

    In this work, information relating to charge states of biomolecule ions in solution obtained using the electrospray ionization mass spectrometry of different biopolymers is analyzed. The data analyses have mainly been carried out by solving an inverse problem of calculating the probabilities of retention of protons and other charge carriers by ionogenic groups of biomolecules with known primary structures. The approach is a new one and has no known to us analogues. A program titled "Decomposition" was developed and used to analyze the charge distribution of ions of native and denatured cytochrome c mass spectra. The possibility of splitting of the charge-state distribution of albumin into normal components, which likely corresponds to various conformational states of the biomolecule, has been demonstrated. The applicability criterion for using previously described method of decomposition of multidimensional charge-state distributions with two charge carriers, e.g., a proton and a sodium ion, to characterize the spatial structure of biopolymers in solution has been formulated. In contrast to known mass-spectrometric approaches, this method does not require the use of enzymatic hydrolysis or collision-induced dissociation of the biopolymers.

  4. Morphological Effect of Non-targeted Biomolecule-Modified MNPs on Reticuloendothelial System.

    Science.gov (United States)

    Li, Xiao; Hu, Yan; Xiao, Jie; Cheng, Dengfeng; Xiu, Yan; Shi, Hongcheng

    2015-12-01

    Magnetic nanoparticles (MNPs) with special morphology were commonly used as biomaterials, while morphological effects of non-targeted biomolecule-modified MNPs on biological behaviors were still unclear. In this research, spherical and rod-like Fe3O4 in a comparable size were synthesized and then surface-modified by bovine serum albumin (BSA) as a model of non-targeted biomolecule-modified MNPs. Morphological effects were featured by TEM and quantification of in vitro phagocytic uptake, as well as the in vivo quantification of particles in reticuloendothelial system (RES)-related organs of normal Kunming mice. For these non-targeted BSA-modified MNPs, intracellular distributions were the same, but the rod-like MNPs were more likely to be uptake by macrophages; furthermore, the BSA-modified MNPs gathered in RES-related organs soon after intravenous injection, but the rod-like ones were expelled from the lung more quickly and expelled from the spleen more slowly. These preliminary results may be referable if MNPs or other similar biomolecule-modified nanoparticles were used.

  5. Electron Paramagnetic Resonance of a Single NV Nanodiamond Attached to an Individual Biomolecule

    Science.gov (United States)

    Teeling-Smith, Richelle M.; Jung, Young Woo; Scozzaro, Nicolas; Cardellino, Jeremy; Rampersaud, Isaac; North, Justin A.; Šimon, Marek; Bhallamudi, Vidya P.; Rampersaud, Arfaan; Johnston-Halperin, Ezekiel; Poirier, Michael G.; Hammel, P. Chris

    2016-05-01

    A key limitation of electron paramagnetic resonance (EPR), an established and powerful tool for studying atomic-scale biomolecular structure and dynamics is its poor sensitivity, samples containing in excess of 10^12 labeled biomolecules are required in typical experiments. In contrast, single molecule measurements provide improved insights into heterogeneous behaviors that can be masked by ensemble measurements and are often essential for illuminating the molecular mechanisms behind the function of a biomolecule. We report EPR measurements of a single labeled biomolecule that merge these two powerful techniques. We selectively label an individual double-stranded DNA molecule with a single nanodiamond containing nitrogen-vacancy (NV) centers, and optically detect the paramagnetic resonance of NV spins in the nanodiamond probe. Analysis of the spectrum reveals that the nanodiamond probe has complete rotational freedom and that the characteristic time scale for reorientation of the nanodiamond probe is slow compared to the transverse spin relaxation time. This demonstration of EPR spectroscopy of a single nanodiamond labeled DNA provides the foundation for the development of single molecule magnetic resonance studies of complex biomolecular systems.

  6. Influence of reactive species on the modification of biomolecules generated from the soft plasma

    Science.gov (United States)

    Attri, Pankaj; Kumar, Naresh; Park, Ji Hoon; Yadav, Dharmendra Kumar; Choi, Sooho; Uhm, Han S.; Kim, In Tae; Choi, Eun Ha; Lee, Weontae

    2015-02-01

    Plasma medicine is an upcoming research area that has attracted the scientists to explore more deeply the utility of plasma. So, apart from the treating biomaterials and tissues with plasma, we have studied the effect of soft plasma with different feeding gases such as Air, N2 and Ar on modification of biomolecules. Hence, in this work we have used the soft plasma on biomolecules such as proteins ((Hemoglobin (Hb) and Myoglobin (Mb)), calf thymus DNA and amino acids. The structural changes or structural modification of proteins and DNA have been studied using circular dichroism (CD), fluorescence spectroscopy, protein oxidation test, gel electrophoresis, UV-vis spectroscopy, dynamic light scattering (DLS) and 1D NMR, while Liquid Chromatograph/Capillary Electrophoresis-Mass Spectrometer (LC/CE-MS) based on qualitative and quantitative bio-analysis have been used to study the modification of amino acids. Further, the thermal analysis of the protein has been studied with differential scanning calorimetry (DSC) and CD. Additionally, we have performed docking studies of H2O2 with Hb and Mb, which reveals that H2O2 molecules preferably attack the amino acids near heme group. We have also shown that N2 gas plasma has strong deformation action on biomolecules and compared to other gases plasma.

  7. Measuring the energy landscape roughness and the transition state location of biomolecules using single molecule mechanical unfolding experiments

    OpenAIRE

    2006-01-01

    Single molecule mechanical unfolding experiments are beginning to provide profiles of the complex energy landscape of biomolecules. In order to obtain reliable estimates of the energy landscape characteristics it is necessary to combine the experimental measurements with sound theoretical models and simulations. Here, we show how by using temperature as a variable in mechanical unfolding of biomolecules in laser optical tweezer or AFM experiments the roughness of the energy landscape can be m...

  8. Health Seeking Behaviour of Elderly in Myanmar

    Directory of Open Access Journals (Sweden)

    Soe Moe

    2012-08-01

    Full Text Available Introduction: Improvement in health technologies and socio economic conditions increase life expectancy of people leading to higher proportion of elderly in total population of every country worldwide. Developing countries have less comprehensive policy and elderly health agenda, and Myanmar is not an exception. The World Health Organization highlighted that aging process and problems related to elderly should be better understood so that effective elderly health prevention can be planned and implemented. However, there are very limited studies in Myanmar for aging health care. Objective: 1 To identify the Health status of aging population in selected townships of upper and lower Myanmar. 2 To identify the health seeking behavior of elderly. 3 To find out the association between the health seeking behavior of elderly and socio-demographic characteristics. Method: This is a cross sectional survey to study health status and health seeking behavior of the elderly people in Myanmar. Study areas are Taungu from Lower Myanmar and Ye Oo from Upper Myanmar both of which are not under cover of elderly project and have no adequate data for elderly health care. Sample size calculation was done by Epi Info StatCalc. Total 729 elderly were under study. According to elderly population in Taungu and Ye Oo, 1/3 of the sample was taken from Taungu and 2/3 taken from Ye Oo. Result: Male, Female ratio of study population is 1:1.44. Around half of elderly population has primary or lower level education, only one third are working but with low income. One third of male and female elderly perceived that they are in good health. Regarding illnesses present at the time of interview, three percent of male and thirteen percent of female did not get treatment. Significant difference between the health seeking behavior of upper and lower Myanmar was seen with chi square alue 1155, P= <00000001. Health seeking behavior was not associated with Gender, ethnicity, religion

  9. Possibility of single biomolecule imaging with coherent amplification of weak scattering x-ray photons.

    Science.gov (United States)

    Shintake, Tsumoru

    2008-10-01

    The number of photons produced by coherent x-ray scattering from a single biomolecule is very small because of its extremely small elastic-scattering cross section and low damage threshold. Even with a high x-ray flux of 3 x 10;{12} photons per 100-nm -diameter spot and an ultrashort pulse of 10 fs driven by a future x-ray free electron laser (x-ray FEL), it has been predicted that only a few 100 photons will be produced from the scattering of a single lysozyme molecule. In observations of scattered x rays on a detector, the transfer of energy from wave to matter is accompanied by the quantization of the photon energy. Unfortunately, x rays have a high photon energy of 12 keV at wavelengths of 1A , which is required for atomic resolution imaging. Therefore, the number of photoionization events is small, which limits the resolution of imaging of a single biomolecule. In this paper, I propose a method: instead of directly observing the photons scattered from the sample, we amplify the scattered waves by superimposing an intense coherent reference pump wave on it and record the resulting interference pattern on a planar x-ray detector. Using a nanosized gold particle as a reference pump wave source, we can collect 10;{4}-10;{5} photons in single shot imaging where the signal from a single biomolecule is amplified and recorded as two-dimensional diffraction intensity data. An iterative phase retrieval technique can be used to recover the phase information and reconstruct the image of the single biomolecule and the gold particle at the same time. In order to precisely reconstruct a faint image of the single biomolecule in Angstrom resolution, whose intensity is much lower than that of the bright gold particle, I propose a technique that combines iterative phase retrieval on the reference pump wave and the digital Fourier transform holography on the sample. By using a large number of holography data, the three-dimensional electron density map can be assembled.

  10. Noble Metal Nanoparticles Applications in Cancer

    Science.gov (United States)

    Conde, João; Doria, Gonçalo; Baptista, Pedro

    2012-01-01

    Nanotechnology has prompted new and improved materials for biomedical applications with particular emphasis in therapy and diagnostics. Special interest has been directed at providing enhanced molecular therapeutics for cancer, where conventional approaches do not effectively differentiate between cancerous and normal cells; that is, they lack specificity. This normally causes systemic toxicity and severe and adverse side effects with concomitant loss of quality of life. Because of their small size, nanoparticles can readily interact with biomolecules both at surface and inside cells, yielding better signals and target specificity for diagnostics and therapeutics. This way, a variety of nanoparticles with the possibility of diversified modification with biomolecules have been investigated for biomedical applications including their use in highly sensitive imaging assays, thermal ablation, and radiotherapy enhancement as well as drug and gene delivery and silencing. Here, we review the available noble metal nanoparticles for cancer therapy, with particular focus on those already being translated into clinical settings. PMID:22007307

  11. Noble Metal Nanoparticles Applications in Cancer

    Directory of Open Access Journals (Sweden)

    João Conde

    2012-01-01

    Full Text Available Nanotechnology has prompted new and improved materials for biomedical applications with particular emphasis in therapy and diagnostics. Special interest has been directed at providing enhanced molecular therapeutics for cancer, where conventional approaches do not effectively differentiate between cancerous and normal cells; that is, they lack specificity. This normally causes systemic toxicity and severe and adverse side effects with concomitant loss of quality of life. Because of their small size, nanoparticles can readily interact with biomolecules both at surface and inside cells, yielding better signals and target specificity for diagnostics and therapeutics. This way, a variety of nanoparticles with the possibility of diversified modification with biomolecules have been investigated for biomedical applications including their use in highly sensitive imaging assays, thermal ablation, and radiotherapy enhancement as well as drug and gene delivery and silencing. Here, we review the available noble metal nanoparticles for cancer therapy, with particular focus on those already being translated into clinical settings.

  12. Stochastic Averaging and Stochastic Extremum Seeking

    CERN Document Server

    Liu, Shu-Jun

    2012-01-01

    Stochastic Averaging and Stochastic Extremum Seeking develops methods of mathematical analysis inspired by the interest in reverse engineering  and analysis of bacterial  convergence by chemotaxis and to apply similar stochastic optimization techniques in other environments. The first half of the text presents significant advances in stochastic averaging theory, necessitated by the fact that existing theorems are restricted to systems with linear growth, globally exponentially stable average models, vanishing stochastic perturbations, and prevent analysis over infinite time horizon. The second half of the text introduces stochastic extremum seeking algorithms for model-free optimization of systems in real time using stochastic perturbations for estimation of their gradients. Both gradient- and Newton-based algorithms are presented, offering the user the choice between the simplicity of implementation (gradient) and the ability to achieve a known, arbitrary convergence rate (Newton). The design of algorithms...

  13. Health information seeking in the information society.

    Science.gov (United States)

    Mukherjee, Abir; Bawden, David

    2012-09-01

    This article is the second student contribution to the Dissertations into Practice feature. It reports on a study that investigated the everyday health information-seeking practices of a small group of the 'general public' and the implications for information-seeking theory and health information provision. The first student article, about the implementation of radio frequency identification (RFID) in a hospital library, was very different, and the two articles illustrate the broad spectrum of possible subjects for the Dissertations into Practice feature. This study was conducted in summer 2011 by Abir Mukherjee for his MSc dissertation in the Library and Information Sciences programme at City University London. Further information and copies of the full dissertation may be obtained from Abir Mukherjee or David Bawden. AM.

  14. Journey to seek the meaning of life

    Institute of Scientific and Technical Information of China (English)

    田亚楠

    2015-01-01

    It’s about my journey to seek the meaning of life. What’s the meaning of life? I found the life of great men were really meaningful, but what about the life of ordinary people? Is their life meaningless? Through my observation and thinking, I have that the life of ordinary people is also meaningful as long as they live their life to the fullest.

  15. Nigeria Seeks Energy Investment from China

    Institute of Scientific and Technical Information of China (English)

    Shan Wenge

    2006-01-01

    @@ Nigeria sent a delegation to China in mid-July to seek investment in the oil-enriched nation. Currently, Nigeria has granted the Chinese oil companies the permits of four oil fields while the Chinese side offered technical support in the energy cooperation field. In addition to the energy sector, Nigeria's invitation of investment this time also covers transportation, finance, telecommunications and manufacturing sector.

  16. Healthcare seeking behaviour among Chinese elderly.

    Science.gov (United States)

    Lu, Hui; Wang, Wei; Xu, Ling; Li, Zhenhong; Ding, Yan; Zhang, Jian; Yan, Fei

    2017-04-18

    Purpose The Chinese population is rapidly ageing before they are rich. The purpose of this paper is to describe healthcare seeking behaviour and the critical factors associated with healthcare seeking behaviour. Design/methodology/approach Using a purposive sampling method, the authors recruited 44 adults aged 60 years or older from three provinces, representing the developed (Shanghai), undeveloped (Ningxia) regions and the regions in between (Hubei). From July to September 2008, using a semi-structured guide, the authors interviewed participants in focus group discussions. Findings The healthcare needs for chronic and catastrophic diseases were high; however, the healthcare demands were low and healthcare utilizations were even lower owing to the limited accessibility to healthcare services, particularly, in underdeveloped rural areas. "Too expensive to see a doctor" was a prime complaint, explaining substantial discrepancies between healthcare needs, demands and use. Care seeking behaviour varied depending on insurance availability, perceived performance, particularly hospital services, and prescription medications. Participants consistently rated increasing healthcare accessibility as a high priority, including offering financial aid, and improving service convenience. Improving social security fairness was the first on the elderly's wish list. Originality/value Healthcare demand and use were lower than needs, and were influenced by multiple factors, primarily, service affordability and efficiency, perceived performance and hospital service quality.

  17. Evaluating information-seeking approaches to metacognition.

    Science.gov (United States)

    Crystal, Jonathon D; Foote, Allison L

    Metacognition has been divided into information monitoring and control processes. Monitoring involves knowing that you know or do not know some information without taking corrective action. Control involves taking corrective action based on the knowledge that you know or do not know some information. In comparative metacognition, considerable attention has been paid toward critically assessing putative evidence for information monitoring in non-human animals. However, less attention has been paid toward critically evaluating evidence for control processes in animals. We briefly review a critique of information-monitoring in animals. Next, we apply these concepts to a number of studies that focus on information seeking in animals. The main type of evidence for control processes in animals come from tube tipping experiments. Before having the opportunity to search for the bait in these experiments, the subject sometimes observes opaque tubes being baited but is sometimes prevented from seeing the baiting. The observations that the subjects look more if baiting was not seen and are more accurate if baiting was seen have been taken as evidence for metacognition in information-seeking experiments. We propose simple alternative hypotheses that are sufficient to explain putative evidence for information seeking in animals without positing metacognition. The alternative explanation focuses on two relatively simple principles: First, an animal has a default "look before you go" response which supersedes random searches in space. Second, spatially guided behavior follows a default rule of "go where something good is." These principles can explain the results of tube tipping experiments without proposing metacognition.

  18. Marilyn Hacker's Cancer Poems

    OpenAIRE

    Twiddy, Iain

    2012-01-01

    Marilyn Hacker's 1994 collection Winter Numbers attempts to come to terms with cancer, including the death of friends from the disease, and Hacker's own mastectomy and chemotherapy. Cancer is problematic for poetry, and for elegy in particular, for a number of conceptual, ethical and mimetic reasons. As it seeks to make progress away from the disease through the patterning of rhyme and meter, metaphor, and the assertion of fertility, cancer poetry finds itself replicating the creatively destr...

  19. Future opportunities for the diagnosis and treatment of prostate cancer

    NARCIS (Netherlands)

    Watson, R.W.; Schalken, J.A.

    2004-01-01

    Despite recent advances, current diagnostic tests and treatment of prostate cancer have limitations. In the last few years, numerous biomolecules have been investigated with the aim of improving diagnosis, including kallikrein-like proteases, growth factors and neuroendocrine markers. Analysis of su

  20. [Determinants of information-seeking about crime and crime prevention: information-seeking on the Internet].

    Science.gov (United States)

    Arai, Takashi; Fuji, Kei; Yoshida, Fujio

    2013-06-01

    This study explores determinants of information-seeking about crime and crime prevention on the Internet, including how it was influenced by personal conversations with others. An analysis of a web survey of mothers (N = 1,040) of 3-12 years old children in Japan indicated that many mothers briefly saw basic information about crime on the Internet, while only a few mothers sought further details. Structural equation modeling indicated the following results. Overall, an increased frequency of conversations about children's safety with family and friends made mothers realize their own responsibility for crime prevention. It also encouraged mothers to seek more information about crime prevention by increasing their willingness to cooperate with neighbors. However, when individuals' realization of responsibility for crime prevention strengthened their attitudes toward the responsibility of the police and government for crime problems, then these attitudes decreased mothers' information-seeking. Finally, while a heightened frequency of conversations about news contents directly increased information-seeking about crime, such conversations could indirectly weaken mothers' information-seeking when mothers emphasized the responsibility of the police and government.

  1. Brines in Seepage Channels as Eluants for Subsurface Relict Biomolecules on Mars?

    Science.gov (United States)

    Wynn-Williams, David D.; Cabrol, Nathalie A.; Grin, Edmond A.; Haberle, Robert M.; Stoker, Carol R.

    2001-06-01

    Water, vital for life, not only maintains the integrity of structural and metabolic biomolecules, it also transports them in solution or colloidal suspension. Any flow of water through a dormant or fossilized microbial community elutes molecules that are potentially recognizable as biomarkers. We hypothesize that the surface seepage channels emanating from crater walls and cliffs in Mars Orbiter Camera images result from fluvial erosion of the regolith as low-temperature hypersaline brines. We propose that, if such flows passed through extensive subsurface catchments containing buried and fossilized remains of microbial communities from the wet Hesperian period of early Mars (~3.5 Ga ago), they would have eluted and concentrated relict biomolecules and delive red them to the surface. Life-supporting low-temperature hypersaline brines in Antarctic desert habitats provide a terrestrial analog for such a scenario. As in the Antarctic, salts would likely have accumulated in water-filled depressions on Mars by seasonal influx and evaporation. Liquid water in the Antarctic cold desert analogs occurs at -80°C in the interstices of shallow hypersaline soils and at -50°C in salt-saturated ponds. Similarly, hypersaline brines on Mars could have freezing points depressed below -50°C. The presence of hypersaline brines on Mars would have extended the amount of time during which life might have evolved. Phototrophic communities are especially important for the search for life because the distinctive structures and longevity of their pigments make excellent biomarkers. The surface seepage channels are therefore not only of geomorphological significance, but also provide potential repositories for biomolecules that could be accessed by landers.

  2. Non-linear vibrational modes in biomolecules: A periodic orbits description

    Energy Technology Data Exchange (ETDEWEB)

    Kampanarakis, Alexandros [Department of Chemistry, University of Crete, and Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas (FORTH), Vasilika Vouton, Heraklion 71110, Crete (Greece); Farantos, Stavros C., E-mail: farantos@iesl.forth.gr [Department of Chemistry, University of Crete, and Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas (FORTH), Vasilika Vouton, Heraklion 71110, Crete (Greece); Daskalakis, Vangelis; Varotsis, Constantinos [Department of Environmental Science and Technology, Cyprus University of Technology, 31 Archbishop Kyprianos St., P.O. Box 50329, 3603 Lemesos (Cyprus)

    2012-05-03

    Graphical abstract: Vibrational frequency shifts in Fe{sup IV} = O species of the active site of cytochrome c oxidase are attributed to changes in the surrounding Coulomb field. Periodic orbits analysis assists to find the most anharmonic modes in model biomolecules. Highlights: Black-Right-Pointing-Pointer Periodic orbits are extended to multidimensional potentials of biomolecules. Black-Right-Pointing-Pointer Highly anharmonic vibrational modes and center-saddle bifurcations are detected. Black-Right-Pointing-Pointer Vibrational frequencies shifts in Oxoferryl species of CcO are observed. - Abstract: The vibrational harmonic normal modes of a molecule, which are valid at energies close to an equilibrium point (a minimum, maximum or saddle of the potential energy surface), are extended by periodic orbits to high energies where anharmonicity and coupling of the degrees of freedom are significant. In this way the assignment of the spectra, and thus the extraction of dynamics in highly excited molecules, can be obtained. New vibrational modes emanating from bifurcations of periodic orbits and long living localized trajectories signal the birth and localization of new quantum states. In this article we review and further study non-linear vibrational modes for model biomolecules such as alanine dipeptide and the active site in the oxoferryl oxidation state of the enzyme cytochrome c oxidase. We locate periodic orbits which exhibit high anhamonicity and lead to center-saddle bifurcations. These modes are associated to an isomerization process in alanine dipeptide and to frequency shifts in the oxoferryl observed by modifying the Coulomb field around the Imidazole-Fe{sup IV} = O species.

  3. Injectable, Biomolecule-Responsive Polypeptide Hydrogels for Cell Encapsulation and Facile Cell Recovery through Triggered Degradation.

    Science.gov (United States)

    Xu, Qinghua; He, Chaoliang; Zhang, Zhen; Ren, Kaixuan; Chen, Xuesi

    2016-11-16

    Injectable hydrogels have been widely investigated in biomedical applications, and increasing demand has been proposed to achieve dynamic regulation of physiological properties of hydrogels. Herein, a new type of injectable and biomolecule-responsive hydrogel based on poly(l-glutamic acid) (PLG) grafted with disulfide bond-modified phloretic acid (denoted as PLG-g-CPA) was developed. The hydrogels formed in situ via enzymatic cross-linking under physiological conditions in the presence of horseradish peroxidase and hydrogen peroxide. The physiochemical properties of the hydrogels, including gelation time and the rheological property, were measured. Particularly, the triggered degradation of the hydrogel in response to a reductive biomolecule, glutathione (GSH), was investigated in detail. The mechanical strength and inner porous structure of the hydrogel were influenced by the addition of GSH. The polypeptide hydrogel was used as a three-dimensional (3D) platform for cell encapsulation, which could release the cells through triggered disruption of the hydrogel in response to the addition of GSH. The cells released from the hydrogel were found to maintain high viability. Moreover, after subcutaneous injection into rats, the PLG-g-CPA hydrogels with disulfide-containing cross-links exhibited a markedly faster degradation behavior in vivo compared to that of the PLG hydrogels without disulfide cross-links, implying an interesting accelerated degradation process of the disulfide-containing polypeptide hydrogels in the physiological environment in vivo. Overall, the injectable and biomolecule-responsive polypeptide hydrogels may serve as a potential platform for 3D cell culture and easy cell collection.

  4. Stable functionalization of germanium surface and its application in biomolecules immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Qi [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); University of Chinese Academy of Sciences, No.19A, Yuquan Road, Beijing 100049 (China); Xu, Baojian [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); Ye, Lin [Sate Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); University of Chinese Academy of Sciences, No.19A, Yuquan Road, Beijing 100049 (China); Tang, Teng; Huang, Shanluo; Du, Xiaowei [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); University of Chinese Academy of Sciences, No.19A, Yuquan Road, Beijing 100049 (China); Bian, Xiaojun; Zhang, Jishen [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); Di, Zengfeng, E-mail: zfdi@mail.sim.ac.cn [Sate Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); Jin, Qinghui [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); Zhao, Jianlong, E-mail: jlzhao@mail.sim.ac.cn [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China)

    2014-10-15

    Highlights: • An effective method to immobilize biomolecules on the functionalized Ge surface. • The surface of Ge was functionalized with 11-Mercaptoundecanoic acid (11-MUA). • Stable and uniform SAMs was obtained on Ge surface after 11-MUA treatment. • The functionalized Ge was employed as substrate for protein immobilization. • Paving the way of Ge for further applications in bioelectronics field. - Abstract: As a typical semiconductor material, germanium (Ge) has the potential to be utilized in microelectronics and bioelectronics. Herein, we present a simple and effective method to immobilize biomolecules on the surface of functionalized Ge. The surface oxide of Ge was removed with the pretreatment of hydrochloric acid and the Cl-terminated Ge reacted with 11-Mercaptoundecanoic acid (11-MUA). The surface of Ge was coated with 11-MUA self-assembled monolayers (SAMs) due to the bonding reaction between the sulfhydryl group of 11-MUA and Cl-terminated Ge. Furthermore, typical biomolecule, a green fluorescent protein was chosen to be immobilized on the surface of the functionalized Ge. Contact angle analysis, atomic force microscopy and X-ray photoelectron spectroscopy were used to study the characteristics including wettability, stability, roughness and component of the functionalized Ge, respectively. Fluorescence microscopy was utilized to indicate the efficiency of protein immobilization on the surface of the functionalized Ge. With these studies, stable and uniform functionalized monolayer was obtained on the surface of Ge after 11-MUA treatment and the functionalized Ge was effectively applied in protein immobilization. Furthermore, this study may pave the way for further applications such as the integration of bioelectronics and biosensors with the attractive semiconductor material-Ge in future work.

  5. Microfossils, biomolecules and biominerals in carbonaceous meteorites: implications to the origin of life

    Science.gov (United States)

    Hoover, Richard B.

    2012-11-01

    Environmental and Field Emission Scanning Electron Microscopy (ESEM and FESEM) investigations have shown that a wide variety of carbonaceous meteorites contain the remains of large filaments embedded within freshly fractured interior surfaces of the meteorite rock matrix. The filaments occur singly or in dense assemblages and mats and are often encased within carbon-rich, electron transparent sheaths. Electron Dispersive X-ray Spectroscopy (EDS) spot analysis and 2D X-Ray maps indicate the filaments rarely have detectable nitrogen levels and exhibit elemental compositions consistent with that interpretation that of the meteorite rock matrix. Many of the meteorite filaments are exceptionally well-preserved and show evidence of cells, cell-wall constrictions and specialized cells and processes for reproduction, nitrogen fixation, attachment and motility. Morphological and morphometric analyses permit many of the filaments to be associated with morphotypes of known genera and species of known filamentous trichomic prokaryotes (cyanobacteria and sulfur bacteria). The presence in carbonaceous meteorites of diagenetic breakdown products of chlorophyll (pristane and phytane) along with indigenous and extraterrestrial chiral protein amino acids, nucleobases and other life-critical biomolecules provides strong support to the hypothesis that these filaments represent the remains of cyanobacteria and other microorganisms that grew on the meteorite parent body. The absence of other life-critical biomolecules in the meteorites and the lack of detectable levels of nitrogen indicate the filaments died long ago and can not possibly represent modern microbial contaminants that entered the stones after they arrived on Earth. This paper presents new evidence for microfossils, biomolecules and biominerals in carbonaceous meteorites and considers the implications to some of the major hypotheses for the Origin of Life.

  6. Photonic crystal fiber based evanescent-wave sensor for detection of biomolecules in aqueous solutions.

    Science.gov (United States)

    Jensen, Jesper B; Pedersen, Lars H; Hoiby, Poul E; Nielsen, Lars B; Hansen, T P; Folkenberg, J R; Riishede, J; Noordegraaf, Danny; Nielsen, Kristian; Carlsen, A; Bjarklev, A

    2004-09-01

    We demonstrate highly efficient evanescent-wave detection of fluorophore-labeled biomolecules in aqueous solutions positioned in the air holes of the microstructured part of a photonic crystal fiber. The air-suspended silica structures located between three neighboring air holes in the cladding crystal guide light with a large fraction of the optical field penetrating into the sample even at wavelengths in the visible range. An effective interaction length of several centimeters is obtained when a sample volume of less than 1 microL is used.

  7. Thiol-ene and photo-cleavage chemistry for controlled presentation of biomolecules in hydrogels.

    Science.gov (United States)

    Grim, Joseph C; Marozas, Ian A; Anseth, Kristi S

    2015-12-10

    Hydrogels have emerged as promising scaffolds in regenerative medicine for the delivery of biomolecules to promote healing. However, increasing evidence suggests that the context that biomolecules are presented to cells (e.g., as soluble verses tethered signals) can influence their bioactivity. A common approach to deliver biomolecules in hydrogels involves physically entrapping them within the network, such that they diffuse out over time to the surrounding tissues. While simple and versatile, the release profiles in such system are highly dependent on the molecular weight of the entrapped molecule relative to the network structure, and it can be difficult to control the release of two different signals at independent rates. In some cases, supraphysiologically high loadings are used to achieve therapeutic local concentrations, but uncontrolled release can then cause deleterious off-target side effects. In vivo, many growth factors and cytokines are stored in the extracellular matrix (ECM) and released on demand as needed during development, growth, and wound healing. Thus, emerging strategies in biomaterial chemistry have focused on ways to tether or sequester biological signals and engineer these bioactive scaffolds to signal to delivered cells or endogenous cells. While many strategies exist to achieve tethering of peptides, protein, and small molecules, this review focuses on photochemical methods, and their usefulness as a mild reaction that proceeds with fast kinetics in aqueous solutions and at physiological conditions. Photo-click and photo-caging methods are particularly useful because one can direct light to specific regions of the hydrogel to achieve spatial patterning. Recent methods have even demonstrated reversible introduction of biomolecules to mimic the dynamic changes of native ECM, enabling researchers to explore how the spatial and dynamic context of biomolecular signals influences important cell functions. This review will highlight how two

  8. Probing single biomolecules in solution using the anti-Brownian electrokinetic (ABEL) trap.

    Science.gov (United States)

    Wang, Quan; Goldsmith, Randall H; Jiang, Yan; Bockenhauer, Samuel D; Moerner, W E

    2012-11-20

    Single-molecule fluorescence measurements allow researchers to study asynchronous dynamics and expose molecule-to-molecule structural and behavioral diversity, which contributes to the understanding of biological macromolecules. To provide measurements that are most consistent with the native environment of biomolecules, researchers would like to conduct these measurements in the solution phase if possible. However, diffusion typically limits the observation time to approximately 1 ms in many solution-phase single-molecule assays. Although surface immobilization is widely used to address this problem, this process can perturb the system being studied and contribute to the observed heterogeneity. Combining the technical capabilities of high-sensitivity single-molecule fluorescence microscopy, real-time feedback control and electrokinetic flow in a microfluidic chamber, we have developed a device called the anti-Brownian electrokinetic (ABEL) trap to significantly prolong the observation time of single biomolecules in solution. We have applied the ABEL trap method to explore the photodynamics and enzymatic properties of a variety of biomolecules in aqueous solution and present four examples: the photosynthetic antenna allophycocyanin, the chaperonin enzyme TRiC, a G protein-coupled receptor protein, and the blue nitrite reductase redox enzyme. These examples illustrate the breadth and depth of information which we can extract in studies of single biomolecules with the ABEL trap. When confined in the ABEL trap, the photosynthetic antenna protein allophycocyanin exhibits rich dynamics both in its emission brightness and its excited state lifetime. As each molecule discontinuously converts from one emission/lifetime level to another in a primarily correlated way, it undergoes a series of state changes. We studied the ATP binding stoichiometry of the multi-subunit chaperonin enzyme TRiC in the ABEL trap by counting the number of hydrolyzed Cy3-ATP using stepwise

  9. From phosphorous to arsenic: changing the classic paradigm for the structure of biomolecules.

    Science.gov (United States)

    Knodle, Ryan; Agarwal, Pratima; Brown, Mark

    2012-05-30

    Biomolecules are composed primarily of the elements carbon, nitrogen, hydrogen, oxygen, sulfur, and phosphorus. The structured assembly of these elements forms the basis for proteins, nucleic acids and lipids. However, the recent discovery of a new bacterium, strain GFAJ-1 of the Halomonadaceae, has shaken the classic paradigms for the architecture of life. Mounting evidence supports the claim that these bacteria substitute arsenic for phosphorus in macromolecules. Herein, we provide a brief commentary and fuel the debate related to what may be a most unusual organism.

  10. Visible wavelength surface-enhanced Raman spectroscopy from In-InP nanopillars for biomolecule detection

    Science.gov (United States)

    Murdoch, B. J.; Portoles, J. F.; Tardio, S.; Barlow, A. J.; Fletcher, I. W.; Cumpson, P. J.

    2016-12-01

    Visible wavelength surface-enhanced Raman spectroscopy (SERS) has been observed from bovine serum albumin (BSA) using In-InP nanopillars synthesised by Ar gas cluster ion beam sputtering of InP wafers. InP provides a high local refractive index for plasmonic In structures, which increases the wavelength of the In surface plasmon resonance. The Raman scattering signal was determined to be up to 285 times higher for BSA deposited onto In-InP nanopillars when compared with Si wafer substrates. These substrates demonstrate the label-free detection of biomolecules by visible wavelength SERS, without the use of noble metal particles.

  11. Mass spectrometry in structural biology and biophysics architecture, dynamics, and interaction of biomolecules

    CERN Document Server

    Kaltashov, Igor A; Desiderio, Dominic M; Nibbering, Nico M

    2012-01-01

    The definitive guide to mass spectrometry techniques in biology and biophysics The use of mass spectrometry (MS) to study the architecture and dynamics of proteins is increasingly common within the biophysical community, and Mass Spectrometry in Structural Biology and Biophysics: Architecture, Dynamics, and Interaction of Biomolecules, Second Edition provides readers with detailed, systematic coverage of the current state of the art. Offering an unrivalled overview of modern MS-based armamentarium that can be used to solve the most challenging problems in biophysics, structural biol

  12. Photonic crystal fiber based evanescent-wave sensor for detection of biomolecules in aqueous solutions

    DEFF Research Database (Denmark)

    Jensen, Jesper Bo Damm; Pedersen, Lars H.; Hoiby, Poul E.

    2004-01-01

    We demonstrate highly efficient evanescent-wave detection of fluorophore-labeled biomolecules in aqueous solutions positioned in the air holes of the microstructured part of a photonic crystal fiber. The air-suspended silica structures located between three neighboring air holes in the cladding c...... crystal guide light with a large fraction of the optical field penetrating into the sample even at wavelengths in the visible range. An effective interaction length of several centimeters is obtained when a sample volume of less than 1 µL is used....

  13. Elucidating the Effect of Biomolecule Structure on Calcium Carbonate Crystal Formation

    Science.gov (United States)

    Kulbok, K. E.; Duckworth, O.

    2011-12-01

    Anthropogenic emissions of carbon dioxide have lead to a steady increase in atmospheric concentration. This greenhouse gas has been identified as a key driver of climate change and also has lead to increased acidification of marine and terrestrial waters. Calcium carbonate precipitation at the Earth's surface is an integral linkage in the global carbon cycle, especially in regards to regulating atmospheric carbon dioxide. As concern for the effect of increasing atmospheric CO2 levels grows, the need to understand calcium carbonate systems escalates concurrently. Calcium carbonate phases are the most abundant group of biominerals; therefore, elucidating the mechanism of biomineralization is critical to understanding CaCO3 precipitation and may aid in the development of novel carbon sequestration strategies. The ubiquity of microorganisms leads to an extensive number of biomolecules present in the Earth's systems, and thus an extensive range of possible effects on CaCO3 formation. Carboxylic acids are very common biomolecules and have a relatively simple structure, thus making them an ideal family of model compounds. This study examines the kinetics, thermodynamics, phase, and morphology of calcium carbonate crystals precipitated in the presence of carboxylate-containing biomolecules, including citric acid, succinic acid, and aspartic acid. The experiments utilize a unique (NH4)2CO3 gas-diffusion reactor, which allows in-situ measurements of chemical conditions during the precipitation and growth of crystals. Continuous monitoring of the in-situ conditions of pCO2, pH, [Ca2+], and optical absorbance provides data on the supersaturation at which nucleation occurs and the kinetics of mineral growth. The use of scanning electron microscopy and X-ray diffraction provides information on the morphology and mineralogy of precipitates. The combination of these data sets will provide an in-depth view of the ideal concentration of calcium ions required for solution saturation

  14. Biomolecule-to-fluorescent-color encoder: modulation of fluorescence emission via DNA structural changes.

    Science.gov (United States)

    Nishimura, Takahiro; Ogura, Yusuke; Yamada, Kenji; Ohno, Yuko; Tanida, Jun

    2014-07-01

    A biomolecule-to-fluorescent-color (B/F) encoder for optical readout of biomolecular information is proposed. In the B/F encoder, a set of fluorescence wavelengths and their intensity levels are used for coding of a biomolecular signal. A hybridization chain reaction of hairpin DNAs labeled with fluorescent reporters was performed to generate the fluorescence color codes. The fluorescence is modulated via fluorescence resonance energy transfer, which is controlled by DNA structural changes. The results demonstrate that fluorescent color codes can be configured based on two wavelengths and five intensities using the B/F encoder, and the assigned codes can be retrieved via fluorescence measurements.

  15. Exploring the nanoscale dynamics of biomolecules with optical microcavities (Conference Presentation)

    Science.gov (United States)

    Vollmer, Frank

    2016-03-01

    Medicine as well as biology increasingly rely on the use of cutting-edge physics and engineering, in order to pursue the next generation nanomedical applications and to address fundamental questions in the life sciences. Central to this task is the study of micro- and nano systems, focusing on how engineered systems combined with natural ones can advance sensing, medicine, and our understanding of how biological systems work. My research addresses these important questions with state-of-the-art biosensor technologies, capable of detecting single biomolecules and their dynamics; and resolving the kinetics of biomolecular systems on timescales ranging from few nanoseconds to several hours

  16. From Phosphorous to Arsenic: Changing the Classic Paradigm for the Structure of Biomolecules

    Directory of Open Access Journals (Sweden)

    Mark Brown

    2012-05-01

    Full Text Available Biomolecules are composed primarily of the elements carbon, nitrogen, hydrogen, oxygen, sulfur, and phosphorus. The structured assembly of these elements forms the basis for proteins, nucleic acids and lipids. However, the recent discovery of a new bacterium, strain GFAJ-1 of the Halomonadaceae, has shaken the classic paradigms for the architecture of life. Mounting evidence supports the claim that these bacteria substitute arsenic for phosphorus in macromolecules. Herein, we provide a brief commentary and fuel the debate related to what may be a most unusual organism.

  17. An examination of the relationships among uncertainty, appraisal, and information-seeking behavior proposed in uncertainty management theory.

    Science.gov (United States)

    Rains, Stephen A; Tukachinsky, Riva

    2015-01-01

    Uncertainty management theory (UMT; Brashers, 2001, 2007) is rooted in the assumption that, as opposed to being inherently negative, health-related uncertainty is appraised for its meaning. Appraisals influence subsequent behaviors intended to manage uncertainty, such as information seeking. This study explores the connections among uncertainty, appraisal, and information-seeking behavior proposed in UMT. A laboratory study was conducted in which participants (N = 157) were primed to feel and desire more or less uncertainty about skin cancer and were given the opportunity to search for skin cancer information using the World Wide Web. The results show that desired uncertainty level predicted appraisal intensity, and appraisal intensity predicted information-seeking depth-although the latter relationship was in the opposite direction of what was expected.

  18. Application of inhomogeneous fluid solvation theory to model the distribution and thermodynamics of water molecules around biomolecules.

    Science.gov (United States)

    Huggins, David J

    2012-11-21

    The structures of biomolecules and the strengths of association between them depend critically on interactions with water molecules. Thus, understanding these interactions is a prerequisite for understanding the structure and function of all biomolecules. Inhomogeneous fluid solvation theory provides a framework to derive thermodynamic properties of individual water molecules from a statistical mechanical analysis. In this work, two biomolecules are analysed to probe the distribution and thermodynamics of surrounding water molecules. The great majority of hydration sites are predicted to contribute favourably to the total free energy with respect to bulk water, though hydration sites close to non-polar regions of the solute do not contribute significantly. Analysis of a biomolecule with a positively and negatively charged functional group predicts that a charged species perturbs the free energy of water molecules to a distance of approximately 6.0 Å. Interestingly, short simulations are found to provide converged predictions if samples are taken with sufficient frequency, a finding that has the potential to significantly reduce the required computational cost of such analysis. In addition, the predicted thermodynamic properties of hydration sites with the potential for direct hydrogen bonding interactions are found to disagree significantly for two different water models. This study provides important information on how inhomogeneous fluid solvation theory can be employed to understand the structures and intermolecular interactions of biomolecules.

  19. High-yielding and photolabile approaches to the covalent attachment of biomolecules to surfaces via hydrazone chemistry.

    Science.gov (United States)

    Lee, Ju Hun; Domaille, Dylan W; Noh, Hyunwoo; Oh, Taeseok; Choi, Chulmin; Jin, Sungho; Cha, Jennifer N

    2014-07-22

    The development of strategies to couple biomolecules covalently to surfaces is necessary for constructing sensing arrays for biological and biomedical applications. One attractive conjugation reaction is hydrazone formation--the reaction of a hydrazine with an aldehyde or ketone--as both hydrazines and aldehydes/ketones are largely bioorthogonal, which makes this particular reaction suitable for conjugating biomolecules to a variety of substrates. We show that the mild reaction conditions afforded by hydrazone conjugation enable the conjugation of DNA and proteins to the substrate surface in significantly higher yields than can be achieved with traditional bioconjugation techniques, such as maleimide chemistry. Next, we designed and synthesized a photocaged aryl ketone that can be conjugated to a surface and photochemically activated to provide a suitable partner for subsequent hydrazone formation between the surface-anchored ketone and DNA- or protein-hydrazines. Finally, we exploit the latent functionality of the photocaged ketone and pattern multiple biomolecules on the same substrate, effectively demonstrating a strategy for designing substrates with well-defined domains of different biomolecules. We expect that this approach can be extended to the production of multiplexed assays by using an appropriate mask with sequential photoexposure and biomolecule conjugation steps.

  20. Seeking Help for Psychological Distress in Urban China

    Science.gov (United States)

    Chen, Juan

    2012-01-01

    Based on data gathered through a household survey of 1,474 urban residents in Beijing, this study examines Chinese help-seeking behaviors in times of psychological distress and perceived barriers to seeking professional help. The results demonstrate that most respondents rely on informal means of seeking help whereas mental health and medical…

  1. Adaptive interface for personalizing information seeking.

    Science.gov (United States)

    Narayanan, S; Koppaka, Lavanya; Edala, Narasimha; Loritz, Don; Daley, Raymond

    2004-12-01

    An adaptive interface autonomously adjusts its display and available actions to current goals and abilities of the user by assessing user status, system task, and the context. Knowledge content adaptability is needed for knowledge acquisition and refinement tasks. In the case of knowledge content adaptability, the requirements of interface design focus on the elicitation of information from the user and the refinement of information based on patterns of interaction. In such cases, the emphasis on adaptability is on facilitating information search and knowledge discovery. In this article, we present research on adaptive interfaces that facilitates personalized information seeking from a large data warehouse. The resulting proof-of-concept system, called source recommendation system (SRS), assists users in locating and navigating data sources in the repository. Based on the initial user query and an analysis of the content of the search results, the SRS system generates a profile of the user tailored to the individual's context during information seeking. The user profiles are refined successively and are used in progressively guiding the user to the appropriate set of sources within the knowledge base. The SRS system is implemented as an Internet browser plug-in to provide a seamless and unobtrusive, personalized experience to the users during the information search process. The rationale behind our approach, system design, empirical evaluation, and implications for research on adaptive interfaces are described in this paper.

  2. Memory Complaints Associated with Seeking Clinical Care

    Directory of Open Access Journals (Sweden)

    Carolina Pires

    2012-01-01

    Full Text Available Diagnosis of mild cognitive impairment relies on the presence of memory complaints. However, memory complaints are very frequent in healthy people. The objective of this study was to determine the severity and type of memory difficulties presented by elderly patients who seek for clinical help, as compared to the memory difficulties reported by subjects in the community. Assessment of subjective memory complaints was done with the subjective memory complaints scale (SMC. The mini-mental state examination was used for general cognitive evaluation and the geriatric depression scale for the assessment of depressive symptoms. Eight-hundred and seventy-one nondemented subjects older than 50 years were included. Participants in the clinical setting had a higher total SMC score (10.3±4.2 than those in the community (5.1±3.0. Item 3 of the SMC, Do you ever forget names of family members or friends? contributed significantly more to the variance of the total SMC score in the clinical sample (18% as compared to the community sample (11%. Forgetting names of family members or friends plays an important role in subjective memory complaints in the clinical setting. This symptom is possibly perceived as particularly worrisome and likely drives people to seek for clinical help.

  3. Psychiatric disorders of patients seeking obesity treatment

    Directory of Open Access Journals (Sweden)

    Lin Hung-Yen

    2013-01-01

    Full Text Available Abstract Background Obese and overweight people have a higher risk of both chronic physical illness and mental illness. Obesity is reported to be positively associated with psychiatric disorders, especially in people who seek obesity treatment. At the same time, obesity treatment may be influenced by psychological factors or personality characteristics. This study aimed to understand the prevalence of mental disorders among ethnic Chinese who sought obesity treatment. Methods Subjects were retrospectively recruited from an obesity treatment center in Taiwan. The obesity treatments included bariatric surgery and non-surgery treatment. All subjects underwent a standardized clinical evaluation with two questionnaires and a psychiatric referral when needed. The psychiatric diagnosis was made thorough psychiatric clinic interviews using the SCID. A total of 841 patients were recruited. We compared the difference in psychiatric disorder prevalence between patients with surgical and non-surgical treatment. Results Of the 841 patients, 42% had at least one psychiatric disorder. Mood disorders, anxiety disorders and eating disorders were the most prevalent categories of psychiatric disorders. Females had more mood disorders and eating disorders than males. The surgical group had more binge-eating disorder, adjustment disorder, and sleep disorders than the non-surgical group. Conclusion A high prevalence of psychiatric disorders was found among ethnic Chinese seeking obesity treatment. This is consistent with study results in the US and Europe.

  4. Renal Cancer Biomarkers | NCI Technology Transfer Center | TTC

    Science.gov (United States)

    The National Cancer Institute's Laboratory of Proteomics and Analytical Technologies is seeking statements of capability or interest from parties interested in collaborative research to further develop, evaluate, or commercialize diagnostic, therapeutic and prognostic cancer biomarkers from clinical specimens.

  5. In vitro colocalization of plasmonic nano-biolabels and biomolecules using plasmonic and Raman scattering microspectroscopy

    Science.gov (United States)

    Chaudhari, Kamalesh; Pradeep, Thalappil

    2015-04-01

    An insight into the intracellular fate of theranostics is important for improving their potential in biological applications. In vivo efficacy of plasmonic theranostics depends on our ability to monitor temporal changes in their size, shape, and state of aggregation, and the identification of molecules adsorbed on their surfaces. We develop a technique which combines plasmonic and Raman scattering microspectroscopy to colocalize plasmonic scattering from metallic nanoparticles with the Raman signatures of biomolecules adsorbed on the surface of the former. Using this technique, we have colocalized biomolecules with the plasmonic scattering from silver nanoparticles in the vicinity of Escherichia coli bacteria. To prove the applicability of this setup for the measurements on mammalian cells, imaging of HEK293 cells treated with gold nanoparticles was performed. We discuss the importance of such correlated measurements over individual techniques, although the latter may lead to misinterpretation of results. Finally, with the above-mentioned examples, we have given criteria to improve the specificity of theranostics. We believe that this methodology will be considered as a prime development in the assessment of theranostics.

  6. Disposable pen-shaped capillary gel electrophoresis cartridge for fluorescence detection of bio-molecules

    Science.gov (United States)

    Amirkhanian, Varoujan; Tsai, Shou-Kuan

    2014-03-01

    We introduce a novel and cost-effective capillary gel electrophoresis (CGE) system utilizing disposable pen-shaped gelcartridges for highly efficient, high speed, high throughput fluorescence detection of bio-molecules. The CGE system has been integrated with dual excitation and emission optical-fibers with micro-ball end design for fluorescence detection of bio-molecules separated and detected in a disposable pen-shaped capillary gel electrophoresis cartridge. The high-performance capillary gel electrophoresis (CGE) analyzer has been optimized for glycoprotein analysis type applications. Using commercially available labeling agent such as ANTS (8-aminonapthalene-1,3,6- trisulfonate) as an indicator, the capillary gel electrophoresis-based glycan analyzer provides high detection sensitivity and high resolving power in 2-5 minutes of separations. The system can hold total of 96 samples, which can be automatically analyzed within 4-5 hours. This affordable fiber optic based fluorescence detection system provides fast run times (4 minutes vs. 20 minutes with other CE systems), provides improved peak resolution, good linear dynamic range and reproducible migration times, that can be used in laboratories for high speed glycan (N-glycan) profiling applications. The CGE-based glycan analyzer will significantly increase the pace at which glycoprotein research is performed in the labs, saving hours of preparation time and assuring accurate, consistent and economical results.

  7. Performance Comparison of Systematic Methods for Rigorous Definition of Coarse-Grained Sites of Large Biomolecules.

    Science.gov (United States)

    Zhang, Yuwei; Cao, Zexing; Zhang, John Zenghui; Xia, Fei

    2017-02-27

    Construction of coarse-grained (CG) models for large biomolecules used for multiscale simulations demands a rigorous definition of CG sites for them. Several coarse-graining methods such as the simulated annealing and steepest descent (SASD) based on the essential dynamics coarse-graining (ED-CG) or the stepwise local iterative optimization (SLIO) based on the fluctuation maximization coarse-graining (FM-CG), were developed to do it. However, the practical applications of these methods such as SASD based on ED-CG are subject to limitations because they are too expensive. In this work, we extend the applicability of ED-CG by combining it with the SLIO algorithm. A comprehensive comparison of optimized results and accuracy of various algorithms based on ED-CG show that SLIO is the fastest as well as the most accurate algorithm among them. ED-CG combined with SLIO could give converged results as the number of CG sites increases, which demonstrates that it is another efficient method for coarse-graining large biomolecules. The construction of CG sites for Ras protein by using MD fluctuations demonstrates that the CG sites derived from FM-CG can reflect the fluctuation properties of secondary structures in Ras accurately.

  8. Impact of low-temperature plasmas on Deinococcus radiodurans and biomolecules

    Science.gov (United States)

    Mogul, Rakesh; Bol'shakov, Alexander A.; Chan, Suzanne L.; Stevens, Ramsey M.; Khare, Bishun N.; Meyyappan, M.; Trent, Jonathan D.

    2003-01-01

    The effects of cold plasma on Deinococcus radiodurans, plasmid DNA, and model proteins were assessed using microbiological, spectrometric, and biochemical techniques. In low power O(2) plasma (approximately 25 W, approximately 45 mTorr, 90 min), D. radiodurans, a radiation-resistant bacterium, showed a 99.999% reduction in bioburden. In higher power O(2) plasma (100 W and 500 mTorr), the reduction rate increased about 10-fold and observation by atomic force microscopy showed significant damage to the cell. Damage to cellular lipids, proteins, and chromosome was indicated by losses of infrared spectroscopic peaks at 2930, 1651, 1538, and 1245 cm(-1), respectively. In vitro experiments show that O(2) plasmas induce DNA strand scissions and cross-linking as well as reduction of enzyme activity. The observed degradation and removal of biomolecules was power-dependent. Exposures to 200 W at 500 mTorr removed biomolecules to below detection limits in 60 s. Emission spectroscopy indicated that D. radiodurans cells were volatilized into CO(2), CO, N(2), and H(2)O, confirming that these plasmas were removing complex biological matter from surfaces. A CO(2) plasma was not as effective as the O(2) plasma, indicating the importance of plasma composition and the dominant role of chemical degradation. Together, these findings have implications for NASA planetary protection schemes and for the contamination of Mars.

  9. Candida bombicola as a platform organism for the production of tailor-made biomolecules.

    Science.gov (United States)

    Roelants, Sophie L K W; Saerens, Karen M J; Derycke, Thibaut; Li, Bing; Lin, Yao-Cheng; Van de Peer, Yves; De Maeseneire, Sofie L; Van Bogaert, Inge N A; Soetaert, Wim

    2013-09-01

    The yeast Candida bombicola is capable of producing high amounts (400 g/L) of the biosurfactant sophorolipids. The genetic makeup of this industrially important yeast has recently been uncovered and molecular manipulation techniques have been developed. Hence, all tools for the development of new bioprocesses with C. bombicola are now available. As a proof of concept, the production of two totally different molecules was aimed for: the bioplastic polyhydroxyalkanoate (PHA) and a new-to-nature cellobioselipid-biosurfactant. Integration of the new functionalities at genomic loci necessary for sophorolipid production safeguards the new biomolecules from sophorolipid contamination, while taking advantage of the regulation of the sophorolipid gene cluster. A maximum yield of 2.0% wt/dwt PHA was obtained; furthermore, this is the first time cellobioselipid synthesis by a non-natural producer is reported. We here provided proof of concept that C. bombicola can be transformed into a platform organism for the production of tailor-made biomolecules.

  10. Concentration-related response potentiometric titrations to study the interaction of small molecules with large biomolecules.

    Science.gov (United States)

    Hamidi-Asl, Ezat; Daems, Devin; De Wael, Karolien; Van Camp, Guy; Nagels, Luc J

    2014-12-16

    In the present paper, the utility of a special potentiometric titration approach for recognition and calculation of biomolecule/small-molecule interactions is reported. This approach is fast, sensitive, reproducible, and inexpensive in comparison to the other methods for the determination of the association constant values (Ka) and the interaction energies (ΔG). The potentiometric titration measurement is based on the use of a classical polymeric membrane indicator electrode in a solution of the small-molecule ligand. The biomolecule is used as a titrant. The potential is measured versus a reference electrode and transformed into a concentration-related signal over the entire concentration interval, also at low concentrations, where the millivolt (y-axis) versus log canalyte (x-axis) potentiometric calibration curve is not linear. In the procedure, Ka is calculated for the interaction of cocaine with a cocaine binding aptamer and with an anticocaine antibody. To study the selectivity and cross-reactivity, other oligonucleotides and aptamers are tested, as well as other small ligand molecules such as tetrakis(4-chlorophenyl)borate, metergoline, lidocaine, and bromhexine. The calculated Ka compared favorably to the value reported in the literature using surface plasmon resonance. The potentiometric titration approach called "concentration-related response potentiometry" is used to study molecular interaction for seven macromolecular target molecules and four small-molecule ligands.

  11. Liquid-liquid extraction of biomolecules in downstream processing - A review paper

    Directory of Open Access Journals (Sweden)

    M. E. Silva

    2000-03-01

    Full Text Available Economic analysis shows that protein separation and purification are a very important aspect of biomolecules production and processing. This is particularly true for protein processing which, because of the complexity of the starting material, often requires many steps to reach the levels of purity required for medical and food applications. The separation specialists' task is to develop safe and simple processes to achieve products with a high level of purity. On a large scale, chromatography of proteins is not an easily applied method, although on a laboratory scale it is very effective and relatively simple. When it is scaled up, shortcomings such as discontinuity in the process, slow protein diffusion and large pressure drops in the system are seen. For these reasons a substantial research effort has been directed toward the use of aqueous two-phase systems (ATPSs to replace the initial steps in protein purification and chromatography. This article reviews the chronology and main ATPS fundamentals and discuss the broader applications of this type of system in the extraction and separation of biomolecules.

  12. Precise fabrication of a 5 nm graphene nanopore with a helium ion microscope for biomolecule detection

    Science.gov (United States)

    Deng, Yunsheng; Huang, Qimeng; Zhao, Yue; Zhou, Daming; Ying, Cuifeng; Wang, Deqiang

    2017-01-01

    We report a scalable method to fabricate high-quality graphene nanopores for biomolecule detection using a helium ion microscope (HIM). HIM milling shows promising capabilities for precisely controlling the size and shape, and may allow for the potential production of nanopores at wafer scale. Nanopores could be fabricated at different sizes ranging from 5 to 30 nm in diameter in few minutes. Compared with the current solid-state nanopore fabrication techniques, e.g. transmission electron microscopy, HIM is fast. Furthermore, we investigated the exposure-time dependence of graphene nanopore formation: the rate of pore expansion did not follow a simple linear relationship with exposure time, but a fast expansion rate at short exposure time and a slow rate at long exposure time. In addition, we performed biomolecule detection with our patterned graphene nanopore. The ionic current signals induced by 20-base single-stranded DNA homopolymers could be used as a basis for homopolymer differentiation. However, the charge interaction of homopolymer chains with graphene nanopores, and the conformations of homopolymer chains need to be further considered to improve the accuracy of discrimination.

  13. A comparative study of biomolecule and polymer surface modifications by a surface microdischarge

    Science.gov (United States)

    Bartis, Elliot A. J.; Luan, Pingshan; Knoll, Andrew J.; Graves, David B.; Seog, Joonil; Oehrlein, Gottlieb S.

    2016-02-01

    Cold atmospheric plasma (CAP) sources are attractive sources of reactive species with promising industrial and biomedical applications, but an understanding of underlying surface mechanisms is lacking. A kHz-powered surface microdischarge (SMD) operating with N2/O2 mixtures was used to study the biological deactivation of two immune-stimulating biomolecules: lipopolysaccharide (LPS) and peptidoglycan (PGN), found in bacteria such as Escherichia coli and Staphylococcus aureus, respectively. Model polymers were also studied to isolate specific functional groups. Changes in the surface chemistry were measured to understand which plasma-generated species and surface modifications are important for biological deactivation. The overall goal of this work is to determine which effects of CAP treatment are generic and which bonds are susceptible to attack. CAP treatment deactivated biomolecules, oxidized surfaces, and introduced surface bound NO3. These effects can be controlled by the N2 fraction in O2 and applied voltage and vary among different target surfaces. The SMD was compared with an Ar/O2/N2-fed kHz-powered atmospheric pressure plasma jet and showed much higher surface modifications and surface chemistry tunability compared to the jet. Possible mechanisms are discussed and findings are compared with recent computational investigations. Our results demonstrate the importance of long-lived plasma-generated species and advance an atomistic understanding of CAP-surface interactions.

  14. Helium Atmosphere Chamber for Soft X-ray Spectroscopy of Biomolecules

    Science.gov (United States)

    Carpenter, Matthew Hollis

    X-ray Absorption Spectroscopy (XAS) is a powerful technique that can provide important information for the study of biological systems. The study of the structure and chemistry at the active metal sites in metalloproteins is important not only for the understanding of the function of the molecules themselves, but also in the hope that the mechanisms once understood may lead to advancement in catalytic chemistry and materials. While techniques using high-energy "hard" X-rays have been well developed for over three decades, the highly useful low-energy or "soft" X-ray regime has seen more recent application to biomolecules. Furthermore, the technical necessities of soft X-ray experiments - most notably the need for Ultra-High Vacuum (UHV) - place restrictions on the form and state of the sample and usually preclude liquid or frozen solution measurements. The Helium atmosphere chamber is designed to allow soft XAS of biomolecules and model compounds in a frozen state without exposure to UHV by isolating the sample inside a cryogenic gaseous exchange gas environment. The implementation allows easier sample handling than typical UHV chambers and measurement in conditions ranging from atmosphere (760 Torr) to 100s of mTorr. The system integrates with the existing end station setup at beam line 4.0.2 at the Advanced Light Source at Lawrence Berkeley National Laboratory.

  15. Recent trends in carbon nanomaterial-based electrochemical sensors for biomolecules: A review.

    Science.gov (United States)

    Yang, Cheng; Denno, Madelaine E; Pyakurel, Poojan; Venton, B Jill

    2015-08-05

    Carbon nanomaterials are advantageous for electrochemical sensors because they increase the electroactive surface area, enhance electron transfer, and promote adsorption of molecules. Carbon nanotubes (CNTs) have been incorporated into electrochemical sensors for biomolecules and strategies have included the traditional dip coating and drop casting methods, direct growth of CNTs on electrodes and the use of CNT fibers and yarns made exclusively of CNTs. Recent research has also focused on utilizing many new types of carbon nanomaterials beyond CNTs. Forms of graphene are now increasingly popular for sensors including reduced graphene oxide, carbon nanohorns, graphene nanofoams, graphene nanorods, and graphene nanoflowers. In this review, we compare different carbon nanomaterial strategies for creating electrochemical sensors for biomolecules. Analytes covered include neurotransmitters and neurochemicals, such as dopamine, ascorbic acid, and serotonin; hydrogen peroxide; proteins, such as biomarkers; and DNA. The review also addresses enzyme-based electrodes that are used to detect non-electroactive species such as glucose, alcohols, and proteins. Finally, we analyze some of the future directions for the field, pointing out gaps in fundamental understanding of electron transfer to carbon nanomaterials and the need for more practical implementation of sensors.

  16. DPPH and oxygen free radicals as pro-oxidant of biomolecules.

    Science.gov (United States)

    Letelier, María Eugenia; Molina-Berríos, Alfredo; Cortés-Troncoso, Juan; Jara-Sandoval, José; Holst, Marianne; Palma, Karina; Montoya, Margarita; Miranda, Dante; González-Lira, Víctor

    2008-03-01

    Numerous investigations exist about the alterations that oxygen free radicals can provoke on biomolecules; these modifications can be prevented and/or reversed by different antioxidants agents. On the other hand, 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), a stable nitrogen synthetic radical, is used to evaluate the antioxidant capacity of medicinal herbal products; however, the structural changes that this radical provoke on the herbal active principles are not clear yet. In this work, we compared the redox reactivity of oxygen free radicals and DPPH radical on phospholipids and protein thiol groups present in rat liver microsomes. Cu2+/ascorbate was used as generator system of oxygen free radical and as antioxidant, an extract of Buddleja globosa's leaves. Cu2+/ascorbate provoked microsomal lipid peroxidation, microsomal thiols oxidation and oxygen consumption; all of these phenomena were inhibited by B. globosa extract. On the other hand, DPPH was bleached in different extension by the herbal extract and phosphatidyl choline; beside, DPPH decreased microsomal thiols content, but this phenomenon were not prevented by the herbal extract. Furthermore, DPPH did not induce oxygen consumption and neither modified the oxygen consumption induced by Cu2+/ascorbate. Distinct redox mechanisms may explain the differences between the reactivity of DPPH and oxygen free radicals on biomolecules, which is discussed.

  17. Surface modification of poly(L-lactic acid) with biomolecules to promote endothelialization.

    Science.gov (United States)

    Xia, Yun; Boey, Freddy; Venkatraman, Subbu S

    2010-09-01

    Rapid endothelialization is important for biodegradable blood-contacting devices not only to prevent thrombosis but also to prevent degradation debris from entering the bloodstream and causing further complications. Here the authors report a three-step surface modification method, by which biomolecules, such as gelatin and chitosan, are covalently immobilized on the surface of plasma-treated poly(L-lactic acid) (PLLA) via -COOH groups introduced by acrylic acid grafting polymerization. Surface characterization techniques, including x-ray photoelectron spectroscopy, contact angle measurement, and colorimetric methods for surface density of functional groups, proved the feasibility and stability of this surface modification method. Surface wettability was increased by biomolecules immobilization. The -COOH surface density was measured to be 4.17±0.15 μmol/cm(2), the and amount of gelatin immobilized was 4.8 μg/cm(2). Human umbilical vein endothelial cell was used during in vitro study at seeding density of 10(4) cells/cm(2). PLLA-gAA-gelatin surface was found to enhance cell adhesion, spreading, focal adhesion formation, and proliferation significantly. Chitosan-modified PLLA shows marginally improvement in cell adhesion and proliferation. Endothelialization was achieved within 7 days on both modified PLLA surfaces. In conclusion, this work demonstrates the feasibility of the surface modification method, and its ability to promote complete endothelialization for cardiovascular applications.

  18. Synchrotron and small bio-molecules in gas phase and liquid environment: new opportunities in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Naves de Brito, A. [State University of Campinas (UNICAMP), SP (Brazil). Dept. of Applied Physics

    2011-07-01

    Full text: Two techniques are critically related to the photoelectric law, namely: photoelectron spectroscopy and photoelectron-photoion coincidence spectroscopy. Both are strongly used now a day within synchrotron laboratories. Our group is employing both to investigate fragmentation of bio-molecules in gas phase such as amino acids and DNA basis using V UV and soft x-ray photons. In the near future lager scale instruments developed in Brazil will allow unique opportunities to apply these two spectroscopic methods to molecules immersed in liquids such as water. We will present details from this advanced x-ray source and experimental stations with capabilities not present in other places in the world. Experiments connected to the molecular origin of live will be shown. Among them an experiment where we mimic the atmosphere at Titan moon producing bio- molecules will discussed. Another experiment will be presented where we test the Panspermia viability using special bacteria. We will also present experiments where frozen simple molecules connected to pre-biotic mate- rial are bombardment by UV photons and energetic particles showing interesting trends. Spectroscopic studies of gas phase photo-fragmentation of bio-molecules may be critical to understand in the future these molecules immersed in liquids. We plan to spend some time showing our recent results in this area. (author)

  19. Factors associated with mobile health information seeking among Singaporean women.

    Science.gov (United States)

    Chang, Leanne; Chiuan Yen, Ching; Xue, Lishan; Choo Tai, Bee; Chuan Chan, Hock; Been-Lirn Duh, Henry; Choolani, Mahesh

    2017-01-01

    This study examined effects of age and social psychological factors on women's willingness to be mobile health information seekers. A national survey of 1,878 Singaporean women was conducted to obtain information on women's mobile phone usage, experiences of health information seeking, and appraisals of using mobile phones to seek health information. Results showed that young, middle-aged, and older women exhibited distinct mobile phone usage behaviors, health information-seeking patterns, and assessments of mobile health information seeking. Factors that accounted for their mobile information-seeking intention also varied. Data reported in this study provide insights into mobile health interventions in the future.

  20. Characterization of the binding strengths between boronic acids and cis-diol-containing biomolecules by affinity capillary electrophoresis.

    Science.gov (United States)

    Lü, Chenchen; Liu, Zhen

    2015-01-01

    The affinity of boronic acids toward cis-diol-containing biomolecules has found wide applications in many fields, such as sensing, separation, drug delivery, and functional materials. A sound understanding of the binding interactions will greatly facilitate exquisite applications of this chemistry. Traditional techniques are associated with some apparent drawbacks, so they are only applicable to a limited range of boronic acids and cis-diol-containing biomolecules. This chapter describes an affinity capillary electrophoresis (ACE) method for the characterization of the binding strengths between boronic acids and cis-diol-containing biomolecules. As compared with existing approaches, such as (11)B NMR, the ACE method exhibits several significant advantages: (1) possibility of simultaneous study of multiple interactions, (2) low requirement on the purity of the binding species, (3) widely applicable to almost all types of cis-diol-containing compounds and boronic acids, and (4) high accuracy and precision.

  1. Characterization of and biomolecule immobilization on the biocompatible multi-walled carbon nanotubes generated by functionalization with polyamidoamine dendrimers.

    Science.gov (United States)

    Zhang, Baoling; Chen, Qiong; Tang, Hao; Xie, Qingji; Ma, Ming; Tan, Liang; Zhang, Youyu; Yao, Shouzhuo

    2010-10-01

    Polyamidoamine (PAMAM) dendrimers were covalently tethered onto the surface of multi-walled carbon nanotubes (MWCNTs). The morphology and dispersive properties of the MWCNT-PAMAM hybrids were characterized and the peripheral functional groups were identified. Cytotoxicity to human osteosarcoma MG-63 cells, and protein and DNA immobilization ability of the hybrids were evaluated in detail. The dendrimers were present on the surface of MWCNTs in high density. The MWCNT-PAMAM hybrids exhibited good dispersibility and stability in aqueous solution. We showed that the hybrids are biocompatible, with no obvious cytotoxicity at concentration biomolecule-immobilization ability (bovine serum albumin and 5'-Fam-CAAggTCgTgTAAAggTCAg-3' were used as models). The functionalization of MWCNTs with PAMAM dendrimers improved the biomolecule-immobilization ability 70-fold and simultaneously decreased the cellular toxicity by about 30%. It is expected that the MWCNT-PAMAM hybrids will find promising applications in biosensors and biomolecule delivery systems in gene or protein therapy.

  2. Different Types of Sensation Seeking: A Person-Oriented Approach in Sensation-Seeking Research

    Science.gov (United States)

    Suranyi, Zsuzsanna; Hitchcock, David B.; Hittner, James B.; Vargha, Andras; Urban, Robert

    2013-01-01

    Previous research on sensation seeking (SS) was dominated by a variable-oriented approach indicating that SS level has a linear relation with a host of problem behaviors. Our aim was to provide a person-oriented methodology--a probabilistic clustering--that enables examination of both inter- and intra-individual differences in not only the level,…

  3. Three-dimensional structure determination protocol for noncrystalline biomolecules using x-ray free-electron laser diffraction imaging.

    Science.gov (United States)

    Oroguchi, Tomotaka; Nakasako, Masayoshi

    2013-02-01

    Coherent and intense x-ray pulses generated by x-ray free-electron laser (XFEL) sources are paving the way for structural determination of noncrystalline biomolecules. However, due to the small scattering cross section of electrons for x rays, the available incident x-ray intensity of XFEL sources, which is currently in the range of 10(12)-10(13) photons/μm(2)/pulse, is lower than that necessary to perform single-molecule diffraction experiments for noncrystalline biomolecules even with the molecular masses of megadalton and submicrometer dimensions. Here, we propose an experimental protocol and analysis method for visualizing the structure of those biomolecules by the combined application of coherent x-ray diffraction imaging and three-dimensional reconstruction methods. To compensate the small scattering cross section of biomolecules, in our protocol, a thin vitreous ice plate containing several hundred biomolecules/μm(2) is used as sample, a setup similar to that utilized by single-molecule cryoelectron microscopy. The scattering cross section of such an ice plate is far larger than that of a single particle. The images of biomolecules contained within irradiated areas are then retrieved from each diffraction pattern, and finally provide the three-dimensional electron density model. A realistic atomic simulation using large-scale computations proposed that the three-dimensional structure determination of the 50S ribosomal subunit embedded in a vitreous ice plate is possible at a resolution of 0.8 nm when an x-ray beam of 10(16) photons/500×500 nm(2)/pulse is available.

  4. Determination of partition coefficients of biomolecules in a microfluidic aqueous two phase system platform using fluorescence microscopy.

    Science.gov (United States)

    Silva, D F C; Azevedo, A M; Fernandes, P; Chu, V; Conde, J P; Aires-Barros, M R

    2017-03-03

    Aqueous two phase systems (ATPS) offer great potential for selective separation of a wide range of biomolecules by exploring differences in molecular solubility in each of the two immiscible phases. However, ATPS use has been limited due to the difficulty in predicting the behavior of a given biomolecule in the partition environment together with the empirical and time-consuming techniques that are used for the determination of partition and extraction parameters. In this work, a fast and novel technique based on a microfluidic platform and using fluorescence microscopy was developed to determine the partition coefficients of biomolecules in different ATPS. This method consists of using a microfluidic device with a single microchannel and three inlets. In two of the inlets, solutions containing the ATPS forming components were loaded while the third inlet was fed with the FITC tagged biomolecule of interest prepared in milli-Q water. Using fluorescence microscopy, it was possible to follow the location of the FITC-tagged biomolecule and, by simply varying the pumping rates of the solutions, to quickly test a wide variety of ATPS compositions. The ATPS system is allowed 4min for stabilization and fluorescence micrographs are used to determine the partition coefficient.The partition coefficients obtained were shown to be consistent with results from macroscale ATPS partition. This process allows for faster screening of partition coefficients using only a few microliters of material for each ATPS composition and is amenable to automation. The partitioning behavior of several biomolecules with molecular weights (MW) ranging from 5.8 to 150kDa, and isoelectric points (pI) ranging from 4.7 to 6.4 was investigated, as well as the effect of the molecular weight of the polymer ATPS component.

  5. Quantification of biomolecules in herring (Clupea harengus) industry processing waters and their recovery using electroflocculation and ultrafiltration

    DEFF Research Database (Denmark)

    Osman, Ali; Gringer, Nina; Svendsen, Tore

    2015-01-01

    Four types of herring industry processing waters; refrigerated sea water (RSW), storage water (SW), processing water from cutting (PW) and pre-salting brines (SB) were subjected to chemical characterization and biomolecule recovery using electroflocculation (EF) and ultrafiltration (UF...... and magnesium were the dominating trace elements. EF plus UF in series recovered up to 80% proteins and fatty acids from SB's and reduced chemical oxygen demand by 70%. Foaming and emulsifying properties of biomolecules were improved or unaffected by EF/UF treatment. To conclude, large amounts of biomass...

  6. Seeking for Simplicity in Complex Networks

    CERN Document Server

    Costa, L F

    2007-01-01

    Complex networks can be understood as graphs whose connectivity deviates from those of regular or near-regular graphs (which can be understood as `simple'). While a great deal of the attention so far foressen for complex networks has been duly driven by the above principle, in this work we take the dual approach and address the identification of simplicity, in the sense of regularity, in complex networks. The basic idea is to seek for subgraphs exhibiting small dispersion (e.g. standard deviation or entropy) of local measurements such as the node degree and clustering coefficient. Here we consider two types of subgraphs: (a) those defined by the progressive neighborhoods around each node and (b) subgraphs obtained from sets of nodes presenting similar local measurements. The former approach allows the assignment of a hierarchical regularity index to all network nodes, the latter paves the way for the identification of subgraphs (patches) in the original network, with nearly uniform connectivity. We illustrate...

  7. Model-free stabilization by extremum seeking

    CERN Document Server

    Scheinker, Alexander

    2017-01-01

    With this brief, the authors present algorithms for model-free stabilization of unstable dynamic systems. An extremum-seeking algorithm assigns the role of a cost function to the dynamic system’s control Lyapunov function (clf) aiming at its minimization. The minimization of the clf drives the clf to zero and achieves asymptotic stabilization. This approach does not rely on, or require knowledge of, the system model. Instead, it employs periodic perturbation signals, along with the clf. The same effect is achieved as by using clf-based feedback laws that profit from modeling knowledge, but in a time-average sense. Rather than use integrals of the systems vector field, we employ Lie-bracket-based (i.e., derivative-based) averaging. The brief contains numerous examples and applications, including examples with unknown control directions and experiments with charged particle accelerators. It is intended for theoretical control engineers and mathematicians, and practitioners working in various industrial areas ...

  8. New wave seeks Indonesian coal mining concessions

    Energy Technology Data Exchange (ETDEWEB)

    Symon, A.

    1996-03-01

    A further wave of new mine exploration and development is on the horizon in Indonesia with 40 companies seeking major new concessions. Successful companies will enjoy a more attractive regulatory framework than their predecessors. The Indonesian Government is recasting the terms of the agreements under which it allows private domestic and foreign invested companies to operate large scale operations in order to encourage more investment in the industry. The Government`s intent to encourage expansion of the industry reflects looming pressure to provide sufficient coal to meet ambitious power plant expansion plans, while being able to maintain coal`s now important role as an export earner. In 1995, steam coal exports reached 40 billion tonnes, and contributed more than 1 billion dollars to Indonesia`s trade accounts. With Indonesia facing a widening current account deficit - combined with high foreign debt - the coal industry is playing a not insignificant role in helping to stabilise Indonesia`s external accounts. 1 tab.

  9. Identification of Biomolecular Building Blocks by Recognition Tunneling: Stride towards Nanopore Sequencing of Biomolecules

    Science.gov (United States)

    Sen, Suman

    DNA, RNA and Protein are three pivotal biomolecules in human and other organisms, playing decisive roles in functionality, appearance, diseases development and other physiological phenomena. Hence, sequencing of these biomolecules acquires the prime interest in the scientific community. Single molecular identification of their building blocks can be done by a technique called Recognition Tunneling (RT) based on Scanning Tunneling Microscope (STM). A single layer of specially designed recognition molecule is attached to the STM electrodes, which trap the targeted molecules (DNA nucleoside monophosphates, RNA nucleoside monophosphates or amino acids) inside the STM nanogap. Depending on their different binding interactions with the recognition molecules, the analyte molecules generate stochastic signal trains accommodating their "electronic fingerprints". Signal features are used to detect the molecules using a machine learning algorithm and different molecules can be identified with significantly high accuracy. This, in turn, paves the way for rapid, economical nanopore sequencing platform, overcoming the drawbacks of Next Generation Sequencing (NGS) techniques. To read DNA nucleotides with high accuracy in an STM tunnel junction a series of nitrogen-based heterocycles were designed and examined to check their capabilities to interact with naturally occurring DNA nucleotides by hydrogen bonding in the tunnel junction. These recognition molecules are Benzimidazole, Imidazole, Triazole and Pyrrole. Benzimidazole proved to be best among them showing DNA nucleotide classification accuracy close to 99%. Also, Imidazole reader can read an abasic monophosphate (AP), a product from depurination or depyrimidination that occurs 10,000 times per human cell per day. In another study, I have investigated a new universal reader, 1-(2-mercaptoethyl)pyrene (Pyrene reader) based on stacking interactions, which should be more specific to the canonical DNA nucleosides. In addition

  10. New Chelators for Low Temperature Al(18)F-Labeling of Biomolecules.

    Science.gov (United States)

    Cleeren, Frederik; Lecina, Joan; Billaud, Emilie M F; Ahamed, Muneer; Verbruggen, Alfons; Bormans, Guy M

    2016-03-16

    The Al(18)F labeling method is a relatively new approach that allows radiofluorination of biomolecules such as peptides and proteins in a one-step procedure and in aqueous solution. However, the chelation of the {Al(18)F}(2+) core with the macrocyclic chelators NOTA or NODA requires heating to 100-120 °C. Therefore, we have developed new polydentate ligands for the complexation of {Al(18)F}(2+) with good radiochemical yields at a temperature of 40 °C. The stability of the new Al(18)F-complexes was tested in phosphate buffered saline (PBS) at pH 7.4 and in rat serum. The stability of the Al(18)F-L3 complex was found to be comparable to that of the previously reported Al(18)F-NODA complex up to 60 min in rat serum. Moreover, the biodistribution of Al(18)F-L3 in healthy mice showed the absence of in vivo defluorination since no significant bone uptake was observed, whereas the major fraction of activity at 60 min p.i. was observed in liver and intestines, indicating hepatobiliary clearance of the radiolabeled ligand. The acyclic chelator H3L3 proved to be a good lead candidate for labeling of heat-sensitive biomolecules with fluorine-18. In order to obtain a better understanding of the different factors influencing the formation and stability of the complex, we carried out more in-depth experiments with ligand H3L3. As a proof of concept, we successfully conjugated the new AlF-chelator with the urea-based PSMA inhibitor Glu-NH-CO-NH-Lys to form Glu-NH-CO-NH-Lys(Ahx)L3, and a biodistribution study in healthy mice was performed with the Al(18)F-labeled construct. This new class of AlF-chelators may have a great impact on PET radiochemical space as it will stimulate the rapid development of new fluorine-18 labeled peptides and other heat-sensitive biomolecules.

  11. Identification of biomolecule mass transport and binding rate parameters in living cells by inverse modeling

    Directory of Open Access Journals (Sweden)

    Shirmohammadi Adel

    2006-10-01

    Full Text Available Abstract Background Quantification of in-vivo biomolecule mass transport and reaction rate parameters from experimental data obtained by Fluorescence Recovery after Photobleaching (FRAP is becoming more important. Methods and results The Osborne-Moré extended version of the Levenberg-Marquardt optimization algorithm was coupled with the experimental data obtained by the Fluorescence Recovery after Photobleaching (FRAP protocol, and the numerical solution of a set of two partial differential equations governing macromolecule mass transport and reaction in living cells, to inversely estimate optimized values of the molecular diffusion coefficient and binding rate parameters of GFP-tagged glucocorticoid receptor. The results indicate that the FRAP protocol provides enough information to estimate one parameter uniquely using a nonlinear optimization technique. Coupling FRAP experimental data with the inverse modeling strategy, one can also uniquely estimate the individual values of the binding rate coefficients if the molecular diffusion coefficient is known. One can also simultaneously estimate the dissociation rate parameter and molecular diffusion coefficient given the pseudo-association rate parameter is known. However, the protocol provides insufficient information for unique simultaneous estimation of three parameters (diffusion coefficient and binding rate parameters owing to the high intercorrelation between the molecular diffusion coefficient and pseudo-association rate parameter. Attempts to estimate macromolecule mass transport and binding rate parameters simultaneously from FRAP data result in misleading conclusions regarding concentrations of free macromolecule and bound complex inside the cell, average binding time per vacant site, average time for diffusion of macromolecules from one site to the next, and slow or rapid mobility of biomolecules in cells. Conclusion To obtain unique values for molecular diffusion coefficient and

  12. Research Progress of Exosomes in Lung Cancer Diagnosis and Treatment

    Directory of Open Access Journals (Sweden)

    Hongbo ZOU

    2016-11-01

    Full Text Available As the leading cause of morbidity and cancer related-death worldwide, lung cancer has a serious threat to human health. Exosomes are nanoscale lipid membrane vesicles derived from multivesicles, which containing active biomolecules including proteins, lipids, nucleic acids and etc. Exosomes play important roles in lung cancer initiation and progression by promoting the formation of tumor microenvironment, enhancing tumor invasive and metastasis capability, leading to immunosuppression and resistance to chemoradiotherapy, and also have the application value in early diagnosis and treatment. This review summarizes the research progress of exosomes in tumor initiation and progression, and its roles in diagnosis and treatment of lung cancer.

  13. Silver island film substrates for ultrasensitive fluorescence detection of (bio)molecules.

    Science.gov (United States)

    Szalkowski, Marcin; Ashraf, Khuram U; Lokstein, Heiko; Mackowski, Sebastian; Cogdell, Richard J; Kowalska, Dorota

    2016-01-01

    A silver island film (SIF) substrate was used to demonstrate that Metal-Enhanced Fluorescence (MEF) is a powerful tool to enable detection of emission from (bio)molecules at very low concentrations. The experiments were carried out with the Fenna-Matthews-Olson (FMO) pigment-protein complex from the photosynthetic green sulfur bacterium Chlorobaculum tepidum. FMO was diluted to a level, at which no emission was detectable on a glass substrate. In contrast, the fluorescence of FMO was readily observed on the SIF substrate, even though the emission wavelength of FMO is displaced by over 300 nm from the maximum of the plasmon resonance of the SIF layer. Estimated enhancements of the fluorescence intensity of FMO on SIF are about 40-fold. The enhancement factor correlates with the improvement of the signal-to-noise ratio for FMO emission on SIF substrates.

  14. BioVEC: a program for biomolecule visualization with ellipsoidal coarse-graining.

    Science.gov (United States)

    Abrahamsson, Erik; Plotkin, Steven S

    2009-09-01

    Biomolecule Visualization with Ellipsoidal Coarse-graining (BioVEC) is a tool for visualizing molecular dynamics simulation data while allowing coarse-grained residues to be rendered as ellipsoids. BioVEC reads in configuration files, which may be output from molecular dynamics simulations that include orientation output in either quaternion or ANISOU format, and can render frames of the trajectory in several common image formats for subsequent concatenation into a movie file. The BioVEC program is written in C++, uses the OpenGL API for rendering, and is open source. It is lightweight, allows for user-defined settings for and texture, and runs on either Windows or Linux platforms.

  15. Microreactor and method for preparing a radiolabeled complex or a biomolecule conjugate

    Energy Technology Data Exchange (ETDEWEB)

    Reichert, David E; Kenis, Paul J. A.; Wheeler, Tobias D; Desai, Amit V; Zeng, Dexing; Onal, Birce C

    2015-03-17

    A microreactor for preparing a radiolabeled complex or a biomolecule conjugate comprises a microchannel for fluid flow, where the microchannel comprises a mixing portion comprising one or more passive mixing elements, and a reservoir for incubating a mixed fluid. The reservoir is in fluid communication with the microchannel and is disposed downstream of the mixing portion. A method of preparing a radiolabeled complex includes flowing a radiometal solution comprising a metallic radionuclide through a downstream mixing portion of a microchannel, where the downstream mixing portion includes one or more passive mixing elements, and flowing a ligand solution comprising a bifunctional chelator through the downstream mixing portion. The ligand solution and the radiometal solution are passively mixed while in the downstream mixing portion to initiate a chelation reaction between the metallic radionuclide and the bifunctional chelator. The chelation reaction is completed to form a radiolabeled complex.

  16. Smaller to larger biomolecule detection using a lab-built surface plasmon resonance based instrument

    Science.gov (United States)

    Lukose, J.; Kulal, V.; Chidangil, S.; Sinha, R. K.

    2016-10-01

    We have developed a low-cost surface plasmon resonance (SPR) instrument based on the Kretschmann configuration for biosensing applications. The fabricated instrument is capable of operating in both angular and intensity interrogation schemes. The proposed sensor has proved enormously versatile by detecting a range of analytes with low to high molecular weights. The refractive index based sensor has been used for detecting the variation in the concentration of the aqueous solution of glucose and glycerine. Real time immobilization of protein molecules, bovine serum albumin on a gold (Au) film surface, has also been detected using the SPR imaging technique. Alkanethiol functionalization of the Au surface was performed, and bovine serum albumin was immobilized onto the carboxyl functionalized surface using amine reactive cross linker chemistry. In future, the present approach can also be utilized for the selective detection of a wide range of target biomolecules with the help of specific capture probes, as well as for monitoring protein-drug interactions.

  17. Spatially selective photonic crystal enhanced fluorescence and application to background reduction for biomolecule detection assays.

    Science.gov (United States)

    Chaudhery, Vikram; Huang, Cheng-Sheng; Pokhriyal, Anusha; Polans, James; Cunningham, Brian T

    2011-11-07

    By combining photonic crystal label-free biosensor imaging with photonic crystal enhanced fluorescence, it is possible to selectively enhance the fluorescence emission from regions of the PC surface based upon the density of immobilized capture molecules. A label-free image of the capture molecules enables determination of optimal coupling conditions of the laser used for fluorescence imaging of the photonic crystal surface on a pixel-by-pixel basis, allowing maximization of fluorescence enhancement factor from regions incorporating a biomolecule capture spot and minimization of background autofluorescence from areas between capture spots. This capability significantly improves the contrast of enhanced fluorescent images, and when applied to an antibody protein microarray, provides a substantial advantage over conventional fluorescence microscopy. Using the new approach, we demonstrate detection limits as low as 0.97 pg/ml for a representative protein biomarker in buffer.

  18. Elemental speciation in biomolecules by LC-ICP-MS with magnetic sector and collision cell instruments

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jin [Iowa State Univ., Ames, IA (United States)

    1999-11-08

    A methodology that can monitor and identify inorganic elements in biological and environmental systems was developed. Size exclusion chromatography (SEC) separates biomolecules, which are then nebulized by a microconcentric nebulizer. The resulting aerosol is desolved and introduced into either a high resolution ICP-MS device or a quadrupole device with a collision cell. Because of the high sensitivity and spectral resolution and high sample introduction efficiency, many unusual or difficult elements, such as Cr, Se, Cd and U, can be observed at ambient levels bound to proteins in human serum. These measurements are made in only a few minutes without preliminary isolation and preconcentration steps. Serum samples can be titrated with spikes of various elements to determine which proteins bind a given metal and oxidation state. Experiments concerning the effects of breaking disulfide linkages and denaturation on metal binding in proteins were also investigated. Elemental distribution in liver extract was also obtained.

  19. Selective functionalization and loading of biomolecules in crystalline silicon nanotube field-effect-transistors.

    Science.gov (United States)

    Kwon, Soonshin; Chen, Zack C Y; Noh, Hyunwoo; Lee, Ju Hun; Liu, Hang; Cha, Jennifer N; Xiang, Jie

    2014-07-21

    Crystalline silicon nanotubes (Si NTs) provide distinctive advantages as electrical and biochemical analysis scaffolds through their unique morphology and electrical tunability compared to solid nanowires or amorphous/non-conductive nanotubes. Such potential is investigated in this report. Gate-dependent four-probe current-voltage analysis reveals electrical properties such as resistivity to differ by nearly 3 orders of magnitude between crystalline and amorphous Si NTs. Analysis of transistor transfer characteristics yields a field effect mobility of 40.0 cm(2) V(-1) s(-1) in crystalline Si NTs. The hollow morphology also allows selective inner/outer surface functionalization and loading capability either as a carrier for molecular targets or as a nanofluidic channel for biomolecular assays. We present for the first time a demonstration of internalization of fluorescent dyes (rhodamine) and biomolecules (BSA) in Si NTs as long as 22 μm in length.

  20. Imparting biomolecules to a metal-organic framework material by controlled DNA tetrahedron encapsulation.

    Science.gov (United States)

    Jia, Yongmei; Wei, Benmei; Duan, Ruixue; Zhang, Ying; Wang, Boya; Hakeem, Abdul; Liu, Nannan; Ou, Xiaowen; Xu, Shaofang; Chen, Zhifei; Lou, Xiaoding; Xia, Fan

    2014-08-04

    Recently, the incorporation of biomolecules in Metal-organic frameworks (MOFs) attracts many attentions because of controlling the functions, properties and stability of trapped molecules. Although there are few reports on protein/MOFs composites and their applications, none of DNA/MOFs composite is reported, as far as we know. Here, we report a new composite material which is self-assembled from 3D DNA (guest) and pre-synthesized MOFs (host) by electrostatic interactions and hydrophilic interactions in a well-dispersed fashion. Its biophysical characterization is well analyzed by fluorescence spectroscopy, quartz crystal microbalance (QCM) and transmission electron microscopy (TEM). This new composite material keeps 3D DNA nanostructure more stable than only 3D DNA nanostructure in DI water at room temperature, and stores amounts of genetic information. It will make DNA as a guest for MOFs and MOFs become a new platform for the development of DNA nanotechnology.

  1. Liquid proteins--a new frontier for biomolecule-based nanoscience.

    Science.gov (United States)

    Perriman, Adam W; Mann, Stephen

    2011-08-23

    Solid, liquid, or gas? The physical states adopted by nano-objects such as proteins are critically dependent on the size and range of the intermolecular attractive forces, and as a consequence, pure liquids comprising solventless melts of structurally intact, discrete functional nanoconstructs are conspicuously absent. Here we describe how globular proteins can be surface-engineered such that anhydrous powders of these nanoscale objects melt at close to room temperature to produce solvent-free liquids comprising exceedingly high concentrations of structurally and functionally intact biomolecules. These liquids offer unprecedented opportunities in bionanomaterials research, represent a new phase for protein chemistry, and challenge the existing paradigm on the role of water molecules in protein folding and function.

  2. Poisson-Boltzmann continuum-solvation models: applications to pH-dependent properties of biomolecules.

    Science.gov (United States)

    Antosiewicz, Jan M; Shugar, David

    2011-11-01

    All molecules can be viewed as either discrete or continuous assemblies of electric charges, and electrostatics plays a major role in intermolecular and intramolecular interactions. Moreover, charge distribution within molecules may fluctuate due to the presence of ionizable groups capable of exchanging protons with the environment, leading to pH-dependence of phenomena involving such molecules. Electrostatic aspects of complex shapes and environments of biological molecules, in vitro and in vivo, are relatively well amenable to treatment by Poisson-Boltzmann models, which are attractive in that they possess a clear physical meaning, and can be readily solved by several mathematically sound methods. Here we describe applications of these models to obtain valuable insights into some biologically important pH-dependent properties of biomolecules, such as stability, binding of ligands (including potential drugs), enzymatic activity, conformational transitions, membrane transport and viral entry.

  3. Young learners' use of social media for information seeking

    DEFF Research Database (Denmark)

    Hyldegård, Jette Seiden

    2015-01-01

    Background. Increased use of social media for information seeking and learning calls for more research and knowledge of how these emerging technologies can support students’ learning. Objectives. The focus is on recent studies of young learners’ use of social media for information seeking in an a....... The challenges of using non-traditional social sources for information seeking identified in the studies raise questions of how teachers and information professionals can educate young learners to use social media competently as information seekers and authors of information....... information seeking activities, strategies and preferences can be identified when young learners use social media for information seeking in relation to course work and other study-related work tasks? 2) What motivations can be identified among young learners for using social media for information seeking...

  4. Cocaine seeking by rats is a goal-directed action.

    Science.gov (United States)

    Olmstead, M C; Lafond, M V; Everitt, B J; Dickinson, A

    2001-04-01

    In two experiments rats were trained to self-administer intravenous cocaine on chained schedules using different responses in the initial (drug-seeking) and terminal (drug-taking) links. In both between- (Experiment 1) and within-subject designs (Experiment 2), the drug-taking response was then either extinguished or reinforced in the absence of the opportunity to perform the seeking response. In a subsequent extinction test with the seeking manipulanda alone, the rate of drug seeking was reduced after the prior extinction of the associated taking response. An additional group trained with a sucrose reinforcer showed a comparable devaluation effect. These findings demonstrate that seeking responses for cocaine and food rewards are mediated by a representation of the contingency between seeking responses and the opportunity to take the reward.

  5. Cancer survivors' use of numerous information sources for cancer-related information: does more matter?

    Science.gov (United States)

    Blanch-Hartigan, Danielle; Blake, Kelly D; Viswanath, Kasisomayajula

    2014-09-01

    A large proportion of the 14 million cancer survivors in the USA are actively seeking health information. This study builds on the informed- and shared-decision making literature, examining cancer survivors' health information seeking behaviors to (1) quantify the number of health information sources used; (2) create a demographic profile of patients who report seeking cancer information from numerous sources versus fewer sources in five areas: cancer information overall, disease/treatment, self-care/management, health services, and work/finances; and (3) examine whether seeking cancer information from numerous sources is associated with self-efficacy, fear of recurrence, perceptions of information seeking difficulty, and resultant patient-provider communication. Data came from a survey of post-treatment cancer survivors (N = 501) who responded to a mailed questionnaire about health information seeking. Participants were divided into two groups using a median split: those who sought health information from more than five sources (numerous source seekers) and those that sought information from less than five sources (fewer source seekers). Multivariable logistic regression was used to model differential information seeking behaviors and outcomes for numerous versus fewer source seekers. On average, survivors sought cancer-related information from five different sources. Numerous source seekers were more likely to be women, have higher levels of education, and report fewer problems with cancer information-seeking. Overall, numerous source seekers were no more or less likely to discuss information with their providers or bring conflicting information to their providers. Understanding the characteristics, behaviors, and experiences of survivors who seek cancer-related information from numerous sources can contribute to informed decision making and patient-centered care.

  6. Optimization and characterization of biomolecule immobilization on silicon substrates using (3-aminopropyl)triethoxysilane (APTES) and glutaraldehyde linker

    Energy Technology Data Exchange (ETDEWEB)

    Gunda, Naga Siva Kumar [Department of Mechanical Engineering, University of Alberta, Edmonton, Canada T6G 2G8 (Canada); Singh, Minashree [Department of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada T6G 1C9 (Canada); Norman, Lana [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada T6G 2V4 (Canada); Kaur, Kamaljit [Department of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada T6G 1C9 (Canada); Mitra, Sushanta K., E-mail: sushanta.mitra@ualberta.ca [Department of Mechanical Engineering, University of Alberta, Edmonton, Canada T6G 2G8 (Canada)

    2014-06-01

    In the present work, we developed and optimized a technique to produce a thin, stable silane layer on silicon substrate in a controlled environment using (3-aminopropyl)triethoxysilane (APTES). The effect of APTES concentration and silanization time on the formation of silane layer is studied using spectroscopic ellipsometry and Fourier transform infrared spectroscopy (FTIR). Biomolecules of interest are immobilized on optimized silane layer formed silicon substrates using glutaraldehyde linker. Surface analytical techniques such as ellipsometry, FTIR, contact angle measurement system, and atomic force microscopy are employed to characterize the bio-chemically modified silicon surfaces at each step of the biomolecule immobilization process. It is observed that a uniform, homogenous and highly dense layer of biomolecules are immobilized with optimized silane layer on the silicon substrate. The developed immobilization method is successfully implemented on different silicon substrates (flat and pillar). Also, different types of biomolecules such as anti-human IgG (rabbit monoclonal to human IgG), Listeria monocytogenes, myoglobin and dengue capture antibodies were successfully immobilized. Further, standard sandwich immunoassay (antibody–antigen–antibody) is employed on respective capture antibody coated silicon substrates. Fluorescence microscopy is used to detect the respective FITC tagged detection antibodies bound to the surface after immunoassay.

  7. Combinational Effect of Cell Adhesion Biomolecules and Their Immobilized Polymer Property to Enhance Cell-Selective Adhesion

    Directory of Open Access Journals (Sweden)

    Rio Kurimoto

    2016-01-01

    Full Text Available Although surface immobilization of medical devices with bioactive molecules is one of the most widely used strategies to improve biocompatibility, the physicochemical properties of the biomaterials significantly impact the activity of the immobilized molecules. Herein we investigate the combinational effects of cell-selective biomolecules and the hydrophobicity/hydrophilicity of the polymeric substrate on selective adhesion of endothelial cells (ECs, fibroblasts (FBs, and smooth muscle cells (SMCs. To control the polymeric substrate, biomolecules are immobilized on thermoresponsive poly(N-isopropylacrylamide-co-2-carboxyisopropylacrylamide (poly(NIPAAm-co-CIPAAm-grafted glass surfaces. By switching the molecular conformation of the biomolecule-immobilized polymers, the cell-selective adhesion performances are evaluated. In case of RGDS (Arg-Gly-Asp-Ser peptide-immobilized surfaces, all cell types adhere well regardless of the surface hydrophobicity. On the other hand, a tri-Arg-immobilized surface exhibits FB-selectivity when the surface is hydrophilic. Additionally, a tri-Ile-immobilized surface exhibits EC-selective cell adhesion when the surface is hydrophobic. We believe that the proposed concept, which is used to investigate the biomolecule-immobilized surface combination, is important to produce new biomaterials, which are highly demanded for medical implants and tissue engineering.

  8. Accurate and computationally efficient prediction of thermochemical properties of biomolecules using the generalized connectivity-based hierarchy.

    Science.gov (United States)

    Sengupta, Arkajyoti; Ramabhadran, Raghunath O; Raghavachari, Krishnan

    2014-08-14

    In this study we have used the connectivity-based hierarchy (CBH) method to derive accurate heats of formation of a range of biomolecules, 18 amino acids and 10 barbituric acid/uracil derivatives. The hierarchy is based on the connectivity of the different atoms in a large molecule. It results in error-cancellation reaction schemes that are automated, general, and can be readily used for a broad range of organic molecules and biomolecules. Herein, we first locate stable conformational and tautomeric forms of these biomolecules using an accurate level of theory (viz. CCSD(T)/6-311++G(3df,2p)). Subsequently, the heats of formation of the amino acids are evaluated using the CBH-1 and CBH-2 schemes and routinely employed density functionals or wave function-based methods. The calculated heats of formation obtained herein using modest levels of theory and are in very good agreement with those obtained using more expensive W1-F12 and W2-F12 methods on amino acids and G3 results on barbituric acid derivatives. Overall, the present study (a) highlights the small effect of including multiple conformers in determining the heats of formation of biomolecules and (b) in concurrence with previous CBH studies, proves that use of the more effective error-cancelling isoatomic scheme (CBH-2) results in more accurate heats of formation with modestly sized basis sets along with common density functionals or wave function-based methods.

  9. Photodissociation of a ruthenium(II) arene complex and its subsequent interactions with biomolecules: a density functional theory study.

    Science.gov (United States)

    Wang, Hanlu; DeYonker, Nathan J; Zhang, Xiting; Zhao, Cunyuan; Ji, Liangnian; Mao, Zong-Wan

    2012-10-01

    The piano-stool Ru(II) arene complex [(η⁶-benz)Ru(bpm)(py)]²⁺ (benz = benzene, bpm = 2,2'-bipyrimidine, and py = pyridine), which is conventionally nonlabile (on a timescale and under conditions relevant for biological reactivity), can be activated by visible light to selectively photodissociate the monodentate ligand (py). In the present study, the aquation and binding of the photocontrolled ruthenium(II) arene complex [(η⁶-benz)Ru(bpm)(py)]²⁺ to various biomolecules are studied by density functional theory (DFT) and time-dependent DFT (TDDFT). Potential energy curves (PECs) calculated for the Ru-N (py) bonds in [(η⁶-benz)Ru(bpm)(py)]²⁺ in the singlet and triplet state give useful insights into the photodissociation mechanism of py. The binding energies of the various biomolecules are calculated, which allows the order of binding affinities among the considered nuleic-acid- or protein-binding sites to be discerned. The kinetics for the replacement of water in the aqua complex with biomolecules is also considered, and the results demonstrate that guanine is superior to other biomolecules in terms of coordinating with the Ru(II) aqua adduct, which is in reasonable agreement with experimental observations.

  10. Biomolecule-Assisted Hydrothermal Synthesis and Self-Assembly of Bi2Te3 Nanostring-Cluster Hierarchical Structure

    DEFF Research Database (Denmark)

    Mi, Jianli; Lock, Nina; Sun, Ting;

    2010-01-01

    A simple biomolecule-assisted hydrothermal approach has been developed for the fabrication of Bi2Te3 thermoelectric nanomaterials. The product has a nanostring-cluster hierarchical structure which is composed of ordered and aligned platelet-like crystals. The platelets are100 nm in diameter...

  11. Nucleus-staining with biomolecule-mimicking nitrogen-doped carbon dots prepared by a fast neutralization heat strategy.

    Science.gov (United States)

    Kang, Yan-Fei; Fang, Yang-Wu; Li, Yu-Hao; Li, Wen; Yin, Xue-Bo

    2015-12-11

    Biomolecule-mimicking nitrogen-doped carbon dots (N-Cdots) were synthesized from dopamine by a neutralization heat strategy. Fluorescence imaging of various cells validated their nucleus-staining efficiency. The dopamine-mimicking N-Cdots "trick" nuclear membranes to achieve nuclear localization and imaging.

  12. Optimization and characterization of biomolecule immobilization on silicon substrates using (3-aminopropyl)triethoxysilane (APTES) and glutaraldehyde linker

    Science.gov (United States)

    Gunda, Naga Siva Kumar; Singh, Minashree; Norman, Lana; Kaur, Kamaljit; Mitra, Sushanta K.

    2014-06-01

    In the present work, we developed and optimized a technique to produce a thin, stable silane layer on silicon substrate in a controlled environment using (3-aminopropyl)triethoxysilane (APTES). The effect of APTES concentration and silanization time on the formation of silane layer is studied using spectroscopic ellipsometry and Fourier transform infrared spectroscopy (FTIR). Biomolecules of interest are immobilized on optimized silane layer formed silicon substrates using glutaraldehyde linker. Surface analytical techniques such as ellipsometry, FTIR, contact angle measurement system, and atomic force microscopy are employed to characterize the bio-chemically modified silicon surfaces at each step of the biomolecule immobilization process. It is observed that a uniform, homogenous and highly dense layer of biomolecules are immobilized with optimized silane layer on the silicon substrate. The developed immobilization method is successfully implemented on different silicon substrates (flat and pillar). Also, different types of biomolecules such as anti-human IgG (rabbit monoclonal to human IgG), Listeria monocytogenes, myoglobin and dengue capture antibodies were successfully immobilized. Further, standard sandwich immunoassay (antibody-antigen-antibody) is employed on respective capture antibody coated silicon substrates. Fluorescence microscopy is used to detect the respective FITC tagged detection antibodies bound to the surface after immunoassay.

  13. Microfossils and biomolecules in carbonaceous meteorites: possibility of life in water-bearing asteroids and comets

    Science.gov (United States)

    Hoover, Richard B.

    2014-09-01

    It is well established that carbonaceous meteorites contain water, carbon, biogenic elements and a host of organic chemicals and biomolecules. Several independent lines of evidence indicate that the parent bodies of the CI1 and CM2 carbonaceous meteorites are most probably the C-type asteroids or cometary nuclei. Several of the protein amino acids detected in the meteorites exhibit chirality and have an excess of the L-enantiomer -- such as in the amino acids present in the proteins of all known life forms on Earth. Isotopic studies have established that the amino acids and nucleobases in the CI1 and CM2 carbonaceous meteorites are both indigenous and extraterrestrial. Optical and Scanning Electron Microscopy studies carried out by researchers during the past half century have revealed the presence of complex biogenic microstructures embedded in the rock-matrix of many of carbonaceous meteorites similar to extinct life-forms known as acritarchs and hystrichospheres. Carbonaceous meteorites also contain a wide variety of large filaments that exhibit the complex morphologies and correct size ranges of known genera and species of photosynthetic microorganisms such as cyanobacteria and diatoms. However, EDAX investigations have shown that these carbon-rich filaments typically have nitrogen content below the level of detection (hair and teeth of Pleistocene Mammoths. Hence, the absence of detectable nitrogen in the filaments provides direct evidence that they do not represent recent biological contaminants that invaded these meteorite stones after they were observed to fall to Earth. The spectral and fluorescence properties of pigments found in several species of terrestrial cyanobacteria which are similar to some microfossils found in carbonaceous meteorites may provide valuable clues to help search for evidence for biomolecules and life on the icy moons of Jupiter and Saturn, asteroids and comets.

  14. A Metal-free Click Chemistry Approach for the Assembly and Probing of Biomolecules.

    Science.gov (United States)

    Maity, Sibaprasad; Viazovkina, Ekaterina; Gall, Alexander; Lyubchenko, Yuri

    2016-01-01

    Probing of biomolecular complexes by single-molecule force spectroscopy (SMFS) methods including AFM requires proper and suitable coupling methods for immobilization of biomolecules onto the AFM tip and the surface. The use of flexible tethers for the coupling process has dual advantages. First, they allow the specific immobilization of interacting molecules, and second, their flexibility facilitates the proper orientation of the interacting partners. Recently, we developed an approach termed Flexible Nano Array (FNA) in which interacting partners are located on the same polymeric FNA molecule separated by a flexible segment with a defined length. In this paper, we modified the FNA tether approach by incorporating click chemistry with non-metal modification. FNA was synthesized using DNA synthesis chemistry, in which phosphoramidite (PA) spacers containing six ethylene glycol units were used instead of nucleoside triphosphates. During the synthesis, two T modifiers conjugated to two dibenzocyclooctyl (DBCO) residues were incorporated at selected positions within the FNA. The DBCO functionality allows for coupling azide labeled biomolecules via click chemistry. Amyloid peptide Aβ(14-23) terminated with azide was incorporated into the FNA and the reaction was controlled with mass-spectrometry. Assembly of tethered Aβ(14-23) peptides into dimers was characterized by AFM force spectroscopy experiments in which the AFM tip functionalized with FNA terminated with biotin probed a streptavidin-coated mica surface. The formation of the peptide dimer was verified with force spectroscopy that showed the appearance of a specific fingerprint for dimer dissociation followed by a rupture event for the biotin-streptavidin link. The developed approach is capable of multiple probing events to allow the collection of a large set of data for a quantitative analysis of the force spectroscopy events.

  15. Analysis of mebendazole binding to its target biomolecule by laser flash photolysis.

    Science.gov (United States)

    Jornet, Dolors; Bosca, Francisco; Andreu, Jose M; Domingo, Luis R; Tormos, Rosa; Miranda, Miguel A

    2016-02-01

    Mebendazole (MBZ) and related anticancer benzimidazoles act binding the β-subunit of Tubulin (TU) before dimerization with α-TU with subsequent blocking microtubule formation. Laser flash photolysis (LFP) is a new tool to investigate drug-albumin interactions and to determine binding parameters such as affinity constant or population of binding sites. The aim of this study was to evaluate the interactions between the nonfluorescent mebendazole (MBZ) and its target biomolecule TU using this technique. Before analyzing the MBZ@TU complex it was needed to determine the photophysical properties of MBZ triplet excited state ((3)MBZ(⁎)) in different media. Hence, (3)MBZ(⁎) showed a transient absorption spectrum with maxima at 520 and 375 nm and a lifetime much longer in acetonitrile (12.5 μs) than in water (260 ns). The binding of MBZ to TU produces a greater increase of the lifetime of (3)MBZ(⁎) (25 μs). This fact and the strong electron acceptor capability observed for (3)MBZ* evidence that MBZ must not be located close to any electron donor amino acid of TU such as its tryptophan or cysteine residues. Adding increasing amounts of MBZ to aqueous TU was determined the MBZ-TU binding constant (2.0 ± 0.5 × 10(5)M(-1) at 298K) which decreased with increasing temperature. The LFP technique has proven to be a powerful tool to analyze the binding of drug-TU systems when the drug has a detectable triplet excited state. Results indicate that LFP could be the technique of choice to study the interactions of non-fluorescent drugs with their target biomolecules.

  16. Specific detection of biomolecules in physiological solutions using graphene transistor biosensors.

    Science.gov (United States)

    Gao, Ning; Gao, Teng; Yang, Xiao; Dai, Xiaochuan; Zhou, Wei; Zhang, Anqi; Lieber, Charles M

    2016-12-20

    Nanomaterial-based field-effect transistor (FET) sensors are capable of label-free real-time chemical and biological detection with high sensitivity and spatial resolution, although direct measurements in high-ionic-strength physiological solutions remain challenging due to the Debye screening effect. Recently, we demonstrated a general strategy to overcome this challenge by incorporating a biomolecule-permeable polymer layer on the surface of silicon nanowire FET sensors. The permeable polymer layer can increase the effective screening length immediately adjacent to the device surface and thereby enable real-time detection of biomolecules in high-ionic-strength solutions. Here, we describe studies demonstrating both the generality of this concept and application to specific protein detection using graphene FET sensors. Concentration-dependent measurements made with polyethylene glycol (PEG)-modified graphene devices exhibited real-time reversible detection of prostate specific antigen (PSA) from 1 to 1,000 nM in 100 mM phosphate buffer. In addition, comodification of graphene devices with PEG and DNA aptamers yielded specific irreversible binding and detection of PSA in pH 7.4 1x PBS solutions, whereas control experiments with proteins that do not bind to the aptamer showed smaller reversible signals. In addition, the active aptamer receptor of the modified graphene devices could be regenerated to yield multiuse selective PSA sensing under physiological conditions. The current work presents an important concept toward the application of nanomaterial-based FET sensors for biochemical sensing in physiological environments and thus could lead to powerful tools for basic research and healthcare.

  17. Creating "living" polymer surfaces to pattern biomolecules and cells on common plastics.

    Science.gov (United States)

    Li, Chunyan; Glidle, Andrew; Yuan, Xiaofei; Hu, Zhixiong; Pulleine, Ellie; Cooper, Jon; Yang, Wantai; Yin, Huabing

    2013-05-13

    Creating patterns of biomolecules and cells has been applied widely in many fields associated with the life sciences, including diagnostics. In these applications it has become increasingly apparent that the spatiotemporal arrangement of biological molecules in vitro is important for the investigation of the cellular functions found in vivo. However, the cell patterning techniques often used are limited to creating 2D functional surfaces on glass and silicon. In addition, in general, these procedures are not easy to implement in conventional biological laboratories. Here, we show the formation of a living poly(ethylene glycol) (PEG) layer that can be patterned with visible light on plastic surfaces. This new and simple method can be expanded to pattern multiple types of biomolecule on either a previously formed PEG layer or a plastic substrate. Using common plastic wares (i.e., polyethylene films and polystyrene cell culture Petri-dishes), we demonstrate that these PEG-modified surfaces have a high resistance to protein adsorption and cell adhesion, while at the same time, being capable of undergoing further molecular grafting with bioactive motifs. With a photomask and a fluid delivery system, we illustrate a flexible way to immobilize biological functions with a high degree of 2D and 3D spatial control. We anticipate that our method can be easily implemented in a typical life science laboratory (without the need for specialized lithography equipment) offering the prospect of imparting desirable properties to plastic products, for example, the creation of functional microenvironments in biological studies or reducing biological adhesion to surfaces.

  18. Foreign Entry Modes Under Institutional Pressures: The Impact of Strategic Resource Seeking and Market Seeking Strategies

    Directory of Open Access Journals (Sweden)

    Manuel Portugal Ferreira

    2008-01-01

    Full Text Available http://dx.doi.org/10.5007/2175-8069.2008v10n22p11Multinational corporations (MNCs are subject to the various dimensions of the external institutional environments. Institutional theory suggests that MNCs need to conform to the prevailing rules, norms and procedures of the locations where they operate in order to survive and grow. This means that MNCs need to develop the best possible configuration of strategy-structure for their worldwide operations. Previous research has noted that in these conditions firms may simply seek to follow a referent other. However, MNCs’ specific strategy for a focal foreign operation is likely to determine the entry mode for each host country. In certain circumstances it may be whether MNCs are pursuing a market-seeking strategy or a strategic resource seeking strategy that shapes the entry mode in face of the prevailing institutional pressures. We contribute to the understanding of entry modes into foreign markets as a reflection of a strategic choice that is bound by institutional constraints.

  19. Physical activity information seeking and advertising recall.

    Science.gov (United States)

    Berry, Tanya R; Spence, John C; Plotnikoff, Ronald C; Bauman, Adrian

    2011-04-01

    The purposes of this research were to examine the characteristics of those who look for physical activity-related information, where they find it, and to examine what types of physical activity-related advertisements are recalled (i.e., publicly funded or commercial). These purposes were tested using secondary data analyses from two population health surveys. Results from the first survey (n=1211) showed gender, age, education, and activity-level differences in who is more likely to search for physical activity-related information. Adding the goal of being active into the model made age and activity level no longer significant but gender and education remained significant factors. The Internet was the most often cited source of physical activity information. The second survey (n=1600) showed that adults 55 years of age or older and participants with the least amount of education were more than twice as likely to name commercial advertisements than were participants aged 18-54 years or those with more education. These results help further our understanding of how publicly funded promotional campaigns fare against commercial advertising and also highlight the need to understand physical activity information-seeking behavior on the Internet and its implications for health promotion.

  20. Edward W. Soja. Seeking Spatial Justice

    Directory of Open Access Journals (Sweden)

    Navarrete Cardona Steven

    2012-12-01

    Full Text Available La urbanización ha tomado un curso dramático a nivel mundial durante los últimos veinte años. El crecimiento demográfico, el acelerado cambio tecnológico, los amplios flujos migratorios desde América Latina, Asia y África, hacia Europa y Estados Unidos, así como la división internacional del trabajo y el auge de las comunidades virtuales repercuten no solo de manera visible en la organización espacial urbana del mundo entero, sino también en la reestructuración epistemológica y en los cambios, que, a su vez, tiene al interior la geografía como ciencia. La obra de Edward Soja, Seeking Spatial Justice, aparece en momentos en que la cuestión urbana se convierte en un tema de investigación apremiante en las agendas de diversos investigadores del mundo que tratan de dar cuenta de los profundos cambios que las ciudades enfrentan en los últimos años.

  1. Women's rights, domestic violence, and recourse seeking in rural Bangladesh.

    Science.gov (United States)

    Schuler, Sidney Ruth; Bates, Lisa M; Islam, Farzana

    2008-03-01

    This article seeks to deepen understanding of the reasons that abused women in a resource-poor rural setting seek recourse so seldom and with so little success. Data from in-depth interviews and group discussions are used to explore the range of responses to domestic violence and to examine barriers to recourse seeking. Findings illustrate how the combination of poverty and gender inequality, inequities in the legal framework, and patriarchal attitudes and corruption in both formal and informal institutions at the local level discourage abused women from seeking recourse and decrease the likelihood of a favorable outcome when they do.

  2. Discovering the enzyme mimetic activity of metal-organic framework (MOF) for label-free and colorimetric sensing of biomolecules.

    Science.gov (United States)

    Wang, Ying; Zhu, Yingjing; Binyam, Atsebeha; Liu, Misha; Wu, Yinan; Li, Fengting

    2016-12-15

    A label-free sensing strategy based on the enzyme-mimicking activity of MOF was demonstrated for colorimetric detection of biomolecules. Firstly obvious blue color was observed due to the high efficiency of peroxidase-like catalytic activity of Fe-MIL-88A (an ion-based MOF material) toward 3,3',5,5'-tetramethylbenzidine (TMB). Then in the presence of target biomolecule and corresponding aptamer, the mimetic activity of Fe-MIL-88A can be strongly inhibited and used directly to realize the colorimetric detection. On the basis of the interesting findings, we designed a straightforward, label-free and sensitive colorimetric method for biomolecule detection by using the enzyme mimetic property of MOF coupling with molecular recognition element. Compared with the existed publications, our work breaks the routine way by setting up an inorganic-organic MOF-aptamer hybrid platform for colorimetric determination of biomolecules, expanding the targets scope from H2O2 or glucose to biomolecules. As a proof of concept, thrombin and thrombin aptamer was used as a model analyte. The limit of detection of 10nM can be achieved with naked eyes and ultrahigh selectivity of thrombin toward numerous interfering substances with 10-fold concentration was demonstrated significantly. Of note, the method was further applied for the detection of thrombin in human serum samples, showing the results in agreement with those values obtained in an immobilization buffer by the colorimetric method. This inorganic-organic MOF-aptamer sensing strategy may in principle be universally applicable for the detection of a range of environmental or biomedical molecules of interests.

  3. Mercury and selenium binding biomolecules in terrestrial mammals (Cervus elaphus and Sus scrofa) from a mercury exposed area.

    Science.gov (United States)

    Ropero, M J Patiño; Fariñas, N Rodríguez; Krupp, E; Mateo, R; Nevado, J J Berzas; Martín-Doimeadios, R C Rodríguez

    2016-06-01

    Mercury (Hg) is likely bound to large biomolecules (e.g. proteins) in living organisms, and in order to assess Hg metabolic pathways and possible toxicological effects, it is essential to study these Hg containing biomolecules. However, the exact nature of most metal binding biomolecules is unknown. Such studies are still in their infancy and information on this topic is scarce because the analysis is challenging, mainly due to their lability upon digestion or extraction from the tissue. New analytical methods that allow complex Hg-biomolecules to be analysed intact are needed and only few very recent studies deal with this approach. Therefore, as an initial step towards the characterization of Hg containing biomolecules, an analytical procedure has been optimised using size-exclusion chromatography (SEC) with inductively coupled plasma mass spectrometry (ICP-MS) detection. We applied this technique to elucidate the distribution and elution profile of Hg and Se, and some physiological important elements such as Fe, Ni, Zn and Cu, to assess metal binding profiles in liver and kidney samples of red deer (Cervus elaphus) and wild boar (Sus scrofa) who roam freely within the largest Hg mining district on Earth, Almadén in Spain. Elemental fractionation profiles of the extracts from different tissues were obtained using two different SEC columns (BioSep-SEC-S2000 GL 300-1kDa and Superdex 75 10/300 GL 70-3kDa). Similar profiles of Hg were observed in red deer and wild boar; however, significant differences were evident for liver and kidney. Moreover, the profiles of Se showed a single peak at high-medium molecular weight in all investigated tissues, while co-elution of Hg with Fe, Ni, Zn and Cu was observed.

  4. Attitude and help-seeking for hearing impairment

    NARCIS (Netherlands)

    vandenBrink, RHS; Wit, HP; Kempen, GIJM; vanHeuvelen, MJG

    1996-01-01

    The aim of the present study was to investigate help-seeking for hearing impairment in the elderly, and to compare groups showing dissimilar help-seeking on their attitude toward hearing loss and hearing aids. Attitude factors were based on a revised version of the Health Belief Model, and included

  5. The Information Seeking and Use Behaviors of Retired Investors

    Science.gov (United States)

    O'Connor, Lisa G.

    2013-01-01

    This exploratory study examines the information seeking and use behaviors of a group of US retired or near-retirement investors from everyday life information seeking and serious leisure perspectives. Although primarily qualitative, it also collects and analyzes quantitative data to describe retired investors' information preferences and use.…

  6. Exploring University Students' Online Information Seeking about Prescription Medications

    Science.gov (United States)

    Alkhalaf, Ahmad Abdullah

    2013-01-01

    This study explored university students' information seeking behaviors related to prescription medication (PM) information. Specifically, it examined the different sources students use for PM information, their use and perceptions of online sources, the types of PM information they seek, their concerns about, and methods they apply to verify the…

  7. Investigating the News Seeking Behavior of Young Adults

    Science.gov (United States)

    Qayyum, M. Asim; Williamson, Kirsty; Liu, Ying-Hsang; Hider, Philip

    2010-01-01

    This study investigated the news-seeking and browsing behaviours of young adults, partly in the context of everyday life information seeking (ELIS), in order to explore their perceptions of and attitudes towards print and online news media. The study is significant because traditional print newspapers face a steady decline in their readership with…

  8. Social Support Seeking and Early Adolescent Depression and Anxiety Symptoms

    Science.gov (United States)

    Vélez, Clorinda E.; Krause, Elizabeth D.; McKinnon, Allison; Brunwasser, Steven M.; Freres, Derek R.; Abenavoli, Rachel M.; Gillham, Jane E.

    2016-01-01

    This study examined how social support seeking and rumination interacted to predict depression and anxiety symptoms 6 months later in early adolescents (N = 118; 11-14 years at baseline). We expected social support seeking would be more helpful for adolescents engaging in low rather than high levels of rumination. Adolescents self-reported on all…

  9. Social Comparison Information and Judgments about Depression and Seeking Counseling.

    Science.gov (United States)

    Strohmer, Douglas C.; And Others

    1984-01-01

    Used a role playing technique to examine the influence of social comparison on help seeking attitudes in 80 students. Results indicated that subjects who received serious social comparison information reported the highest depression scores and were more willing to seek counseling help. (JAC)

  10. Social Goals and Willingness to Seek Help for School Violence

    Science.gov (United States)

    Yablon, Yaacov B.

    2012-01-01

    The relation between students' social goals and their willingness to seek help for school violence was examined. Four hundred and sixty-two students from sixth, eighth, and tenth grades responded to vignettes used to assess willingness to seek help from teachers and friends for dealing with relational and physical violence. Intimacy goals enhanced…

  11. Help-Seeking Behaviors of Accounting Principles I Students.

    Science.gov (United States)

    Moncada, Susan M.; Sanders, Joseph C.

    This study examined the help-seeking propensities of college students enrolled in a "Principles of Financial Accounting I" course. A total of 364 students responded to a questionnaire on various aspects of help-seeking behavior. It was found that the most frequently used source of help was friends or classmates, followed by the instructor and the…

  12. Spatial factors as contextual qualifiers of information seeking

    Directory of Open Access Journals (Sweden)

    R. Savolainen

    2006-01-01

    Full Text Available Introduction. This paper investigates the ways in which spatial factors have been approached in information seeking studies. The main attention was focused on studies discussing information seeking on the level of source selection and use. Method. Conceptual analysis of about 100 articles and books thematizing spatial issues of information seeking. Due to research economy, the main attention was paid to studies on everyday life information seeking. Results. Three major viewpoints were identified with regard to the degree of objectivity of spatial factors. The objectifying approach conceives of spatial factors as external and entity-like qualifiers that primarly constrain information seeking. The realistic-pragmatic approach emphasizes the ways in which the availabilty of information sources in different places such as daily work environments orient information seeking. The perspectivist approach focuses on how people subjectively assess the significance of various sources by means of spatial constructs such as information horizons. Conclusion. Spatial factors are centrally important contextual qualifiers of information seeking. There is a need to further explore the potential of the above viewpoints by relating the spatial and temporal factors of information seeking.

  13. Hypothalamic control of male aggression-seeking behavior.

    Science.gov (United States)

    Falkner, Annegret L; Grosenick, Logan; Davidson, Thomas J; Deisseroth, Karl; Lin, Dayu

    2016-04-01

    In many vertebrate species, certain individuals will seek out opportunities for aggression, even in the absence of threat-provoking cues. Although several brain areas have been implicated in the generation of attack in response to social threat, little is known about the neural mechanisms that promote self-initiated or 'voluntary' aggression-seeking when no threat is present. To explore this directly, we utilized an aggression-seeking task in which male mice self-initiated aggression trials to gain brief and repeated access to a weaker male that they could attack. In males that exhibited rapid task learning, we found that the ventrolateral part of the ventromedial hypothalamus (VMHvl), an area with a known role in attack, was essential for aggression-seeking. Using both single-unit electrophysiology and population optical recording, we found that VMHvl neurons became active during aggression-seeking and that their activity tracked changes in task learning and extinction. Inactivation of the VMHvl reduced aggression-seeking behavior, whereas optogenetic stimulation of the VMHvl accelerated moment-to-moment aggression-seeking and intensified future attack. These data demonstrate that the VMHvl can mediate both acute attack and flexible seeking actions that precede attack.

  14. Young learners' use of social media for information seeking

    DEFF Research Database (Denmark)

    Hyldegård, Jette Seiden

    2015-01-01

    Background. Increased use of social media for information seeking and learning calls for more research and knowledge of how these emerging technologies can support students’ learning. Objectives. The focus is on recent studies of young learners’ use of social media for information seeking...... in an academic context. Methods. The research is based on critical reading of core library and information science (LIS) journals and a selected number of conference proceedings spanning 2010 to 2014. The examination of the selected journals and proceedings was guided by two general questions: 1) Which...... information seeking activities, strategies and preferences can be identified when young learners use social media for information seeking in relation to course work and other study-related work tasks? 2) What motivations can be identified among young learners for using social media for information seeking...

  15. Detection Techniques for Biomolecules using Semi-Conductor Nanocrystals and Magnetic Beads as Labels

    Science.gov (United States)

    Chatterjee, Esha

    Continued interest in the development of miniaturized and portable analytical platforms necessitates the exploration of sensitive methods for the detection of trace analytes. Nanomaterials, on account of their unique physical and chemical properties, are not only able to overcome many limitations of traditional detection reagents but also enable the exploration of many new signal transduction technologies. This dissertation presents a series of investigations of alternative detection techniques for biomolecules, involving the use of semi-conductor nanocrystals and magnetic beads as labels. Initial research focused on the development of quantum dot-encapsulating liposomes as a novel fluorescent label for immunoassays. This hybrid nanomaterial was anticipated to overcome the drawbacks presented by traditional fluorophores as well as provide significant signal amplification. Quantum dot-encapsulating liposomes were synthesized by the method of thin film hydration and characterized. The utility of these composite nanostructures for bioanalysis was demonstrated. However, the longterm instability of the liposomes hampered quantitative development. A second approach for assay development exploited the ability of gold nanoparticles to quench the optical signals obtained from quantum dots. The goal of this study was to demonstrate the feasibility of using aptamer-linked nanostructures in FRET-based quenching for the detection of proteins. Thrombin was used as the model analyte in this study. Experimental parameters for the assay were optimized. The assay simply required the mixing of the sample with the reagents and could be completed in less than an hour. The limit of detection for thrombin by this method was 5 nM. This homogeneous assay can be easily adapted for the detection of a wide variety of biochemicals. The novel technique of ferromagnetic resonance generated in magnetic bead labels was explored for signal transduction. This inductive detection technique lends

  16. Neural substrate of cold-seeking behavior in endotoxin shock.

    Directory of Open Access Journals (Sweden)

    Maria C Almeida

    Full Text Available Systemic inflammation is a leading cause of hospital death. Mild systemic inflammation is accompanied by warmth-seeking behavior (and fever, whereas severe inflammation is associated with cold-seeking behavior (and hypothermia. Both behaviors are adaptive. Which brain structures mediate which behavior is unknown. The involvement of hypothalamic structures, namely, the preoptic area (POA, paraventricular nucleus (PVH, or dorsomedial nucleus (DMH, in thermoregulatory behaviors associated with endotoxin (lipopolysaccharide [LPS]-induced systemic inflammation was studied in rats. The rats were allowed to select their thermal environment by freely moving in a thermogradient apparatus. A low intravenous dose of Escherichia coli LPS (10 microg/kg caused warmth-seeking behavior, whereas a high, shock-inducing dose (5,000 microg/kg caused cold-seeking behavior. Bilateral electrocoagulation of the PVH or DMH, but not of the POA, prevented this cold-seeking response. Lesioning the DMH with ibotenic acid, an excitotoxin that destroys neuronal bodies but spares fibers of passage, also prevented LPS-induced cold-seeking behavior; lesioning the PVH with ibotenate did not affect it. Lesion of no structure affected cold-seeking behavior induced by heat exposure or by pharmacological stimulation of the transient receptor potential (TRP vanilloid-1 channel ("warmth receptor". Nor did any lesion affect warmth-seeking behavior induced by a low dose of LPS, cold exposure, or pharmacological stimulation of the TRP melastatin-8 ("cold receptor". We conclude that LPS-induced cold-seeking response is mediated by neuronal bodies located in the DMH and neural fibers passing through the PVH. These are the first two landmarks on the map of the circuitry of cold-seeking behavior associated with endotoxin shock.

  17. Distribution of biomolecules in porous nitrocellulose membrane pads using confocal laser scanning microscopy and high-speed cameras.

    Science.gov (United States)

    Mujawar, Liyakat Hamid; Maan, Abid Aslam; Khan, Muhammad Kashif Iqbal; Norde, Willem; van Amerongen, Aart

    2013-04-02

    The main focus of our research was to study the distribution of inkjet printed biomolecules in porous nitrocellulose membrane pads of different brands. We produced microarrays of fluorophore-labeled IgG and bovine serum albumin (BSA) on FAST, Unisart, and Oncyte-Avid slides and compared the spot morphology of the inkjet printed biomolecules. The distribution of these biomolecules within the spot embedded in the nitrocellulose membrane was analyzed by confocal laser scanning microscopy in the "Z" stack mode. By applying a "concentric ring" format, the distribution profile of the fluorescence intensity in each horizontal slice was measured and represented in a graphical color-coded way. Furthermore, a one-step diagnostic antibody assay was performed with a primary antibody, double-labeled amplicons, and fluorophore-labeled streptavidin in order to study the functionality and distribution of the immune complex in the nitrocellulose membrane slides. Under the conditions applied, the spot morphology and distribution of the primary labeled biomolecules was nonhomogenous and doughnut-like on the FAST and Unisart nitrocellulose slides, whereas a better spot morphology with more homogeneously distributed biomolecules was observed on the Oncyte-Avid slide. Similar morphologies and distribution patterns were observed when the diagnostic one-step nucleic acid microarray immunoassay was performed on these nitrocellulose slides. We also investigated possible reasons for the differences in the observed spot morphology by monitoring the dynamic behavior of a liquid droplet on and in these nitrocellulose slides. Using high speed cameras, we analyzed the wettability and fluid flow dynamics of a droplet on the various nitrocellulose substrates. The spreading of the liquid droplet was comparable for the FAST and Unisart slides but different, i.e., slower, for the Oncyte-Avid slide. The results of the spreading of the droplet and the penetration behavior of the liquid in the

  18. Critical Thinking I:Seeking Conceptual Clarity

    Institute of Scientific and Technical Information of China (English)

    ZHAN Lin; LEE Shirleatha; FLEMING Belinda

    2014-01-01

    “Critical Thinking”在20世纪90年代初引入中国护理界,被译为“评判性思维(批判性思维)”,相关护理研究多着眼于其字面含义的“评判”“批判”,然而“Critical Thinking”是指“以解决问题为目的导向,基于对问题的认知,训练有素且公正地收集、评估和分析相关信息,不断质疑、反思和评判,进而应用逻辑推理和归纳的方法,做出最佳决策的综合性思维模式”,故“评判”“批判”仅仅是“Critical Thinking”的一部分,这也就导致了部分护理工作者对“Critical Thinking”概念的局限性理解和学术上的误导。为厘清“Critical Thinking”的概念,本刊名誉主编美国护理科学院院士、孟菲斯大学鲁文贝格护理学院院长、终身教授、护理学博士詹林教授,以及鲁文贝格护理学院Lee Shirleatha教授和Fleming Belinda教授共同撰写3篇专题稿件,本期刊登第1篇《Critical Thinking I:Seeking Conceptual Clarity》,从哲学、心理学、教育学和护理学角度阐释“Critical Thinking”的定义、特征及构成要素,并介绍“Critical Thinking”在护理临床实践和护理教育领域的引申含义,旨在引发护理同仁针对“Critical Thinking”的思考与讨论,欢迎广大读者就该主题撰稿探讨。投稿方式为登录护理学报网站www.hlxb.com.cn在线投稿,文题后加括号注明“讨论”二字。

  19. Expression profiling of 21 biomolecules in locally advanced nasopharyngeal carcinomas of Caucasian patients

    Directory of Open Access Journals (Sweden)

    Krikelis Dimitrios

    2013-01-01

    Full Text Available Abstract Background Since scarce data exist on the pathogenesis of nasopharyngeal carcinoma in Caucasian patients, we attempted to elucidate the responsible molecular pathways in this patient population. Methods Formalin-fixed paraffin-embedded tumor tissue samples from 107 patients, diagnosed with locally-advanced nasopharyngeal carcinoma and treated with chemotherapy or chemo-radiotherapy, were analyzed by immunohistochemistry for the expression of the following proteins: E-cadherin, P-cadherin, Fascin-1, Cyclin D1, COX-2, EGFR, VEGF-A, VEGF-C, VEGFR-2, VEGFR-3, ERCC1, p53, p63, Ki67, MAPT, phospho-p44/42MAPK, PTEN, phospho-AKT, phospho-mTOR, and phospho-GSK-3β. EBER status was assessed by in situ hybridization. The majority of the cases were included in tissue microarray. All stains were performed and assessed centrally by two pathologists. The median follow-up time was 76.8 (42.3 – 99.2 months. Results Biomolecules expressed in >90% of cases were: p53, COX-2, P-cadherin, EBER, phospho-GSK-3β, and Fascin-1. WHO II+III tumors were more frequently EBER & PTEN positive and VEGF-A negative. Advanced age was significantly associated with positive phospho-GSK-3β and ERCC1 expression; male gender with positive phospho-AKT and phospho-p44/42MAPK; and worse performance status (1 or 2 with negative Ki67, ERCC1, PTEN, and phospho-mTOR expression. Earlier disease stage was closely associated with p63, MAPT, PTEN, and Cyclin D1 positivity. Univariate Cox regression analysis highlighted Cyclin D1 as a negative prognostic factor for disease-free survival (p=0.034 and EBER as a positive one for overall survival (p=0.048. In multivariate analysis, advanced age and stage, poor performance status, and positive ERCC1 emerged as predictors of worse disease-free and overall survival, as opposed to positive phospho-mTOR. Clustering analysis defined two protein-expression groups being predictive of better overall survival (p=0.043. Conclusions Our study is the

  20. Seeking Haven and Seeking Jobs: Migrant Workers’ Networks in Two Thai Locales

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    Nobpaon Rabibhadana

    2013-08-01

    Full Text Available Thailand has seen a large increase in migrant workers from Myanmar since the 1990s. A constant flow of migrants arrive to seek refuge from dire circumstances in their homeland and/or to seek better work opportunities. They have adapted to changing state policy regarding their migrant status and work permits as well as to more immediate means of control. Previous works on this subject have tended either toward macro-level policy and economics, or more journalistic accounts of individual migrant experiences. Little attention has been paid to differences in the migrant processes and networks formed across the border and within the country.  In this paper two locales, one on the border (Mae Sot and one in the interior (Samut Songkhram, are compared based on interviews conducted with migrant workers on their mode of arrival, living and working conditions, migrant status and control, and how they form networks and relations within and across the border. By comparing the two locales, rather than emphasize how the state and geopolitical space define mobility we argue that transnational migrant workers formulate and define their space through adaptive networks in articulation with geopolitical factors as well as local socioeconomic and historical-cultural dynamics. The dynamics among macro policies, micro-level agency of migrants, and meso-level networks define each locale.

  1. A Review on Information Seeking Behaviour Literature in Iran

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    shiva yari

    2014-12-01

    Full Text Available This article reviews the condition of information seeking behavior in Iran with analytical and qualittatire approaches to exhibit a clear, scientific, and read condition of it. Published literature has been reviewed both in theoretical bases and accomplished researches. So, all published literature including books, articles, theses, and research plans that has been released and distributed in Iran and were effective in this domain, has been studied. Reviews showed that the information seeking behavior has had a developing trend in quality and quantity form the last seventeen years of its emerging in Iran. Lower than 4% of published literature has been translated. Most resources have studied the information seeking behavior in research form. Scholar’s information seeking behavior has been done in most researches (about 34% of all researches. Then students’ information seeking behavior (about 17% and researches’ information seeking behavior (about 14% has been done. The least attention has been about examination of publics’ information seeking behavior and public library members. Reviews show that most researches have been at science and research units of Azad University in Tehran and Ahvaz. According to accomplished analysis, most articles has been published in National Studies of Librarianship and Information quarterly (previously Faslname Ketab, Processing and management of Information quarterly, and Librarianship and Information quarterly, respectively. This domain has been focused by librarians and somewhat by specialists of agricultural, social communication science, course planning, and government management fields.

  2. Extinction of drug seeking: Neural circuits and approaches to augmentation.

    Science.gov (United States)

    McNally, Gavan P

    2014-01-01

    Extinction training can reduce drug seeking behavior. This article reviews the neural circuits that contribute to extinction and approaches to enhancing the efficacy of extinction. Extinction of drug seeking depends on cortical-striatal-hypothalamic and cortical-hypothalamic-thalamic pathways. These pathways interface, in the hypothalamus and thalamus respectively, with the neural circuits controlling reinstatement of drug seeking. The actions of these pathways at lateral hypothalamic orexin neurons, and of perifornical/dorsomedial hypothalamic derived opioid peptides at kappa opioid receptors in the paraventricular thalamus, are important for inhibiting drug seeking. Despite effectively reducing or inhibiting drug seeking in the short term, extinguished drug seeking is prone to relapse. Three different strategies to augment extinction learning or retrieval are reviewed: pharmacological augmentation, retrieval - extinction training, and provision of extinction memory retrieval cues. These strategies have been used in animal models and with human drug users to enhance extinction or cue exposure treatments. They hold promise as novel strategies to promote abstinence from drug seeking. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'.

  3. Graphene: The Missing Piece for Cancer Diagnosis?

    Science.gov (United States)

    Cruz, Sandra M. A.; Girão, André F.; Gonçalves, Gil; Marques, Paula A. A. P.

    2016-01-01

    This paper reviews recent advances in graphene-based biosensors development in order to obtain smaller and more portable devices with better performance for earlier cancer detection. In fact, the potential of Graphene for sensitive detection and chemical/biological free-label applications results from its exceptional physicochemical properties such as high electrical and thermal conductivity, aspect-ratio, optical transparency and remarkable mechanical and chemical stability. Herein we start by providing a general overview of the types of graphene and its derivatives, briefly describing the synthesis procedure and main properties. It follows the reference to different routes to engineer the graphene surface for sensing applications with organic biomolecules and nanoparticles for the development of advanced biosensing platforms able to detect/quantify the characteristic cancer biomolecules in biological fluids or overexpressed on cancerous cells surface with elevated sensitivity, selectivity and stability. We then describe the application of graphene in optical imaging methods such as photoluminescence and Raman imaging, electrochemical sensors for enzymatic biosensing, DNA sensing, and immunosensing. The bioquantification of cancer biomarkers and cells is finally discussed, particularly electrochemical methods such as voltammetry and amperometry which are generally adopted transducing techniques for the development of graphene based sensors for biosensing due to their simplicity, high sensitivity and low-cost. To close, we discuss the major challenges that graphene based biosensors must overcome in order to reach the necessary standards for the early detection of cancer biomarkers by providing reliable information about the patient disease stage. PMID:26805845

  4. Graphene: The Missing Piece for Cancer Diagnosis?

    Directory of Open Access Journals (Sweden)

    Sandra M. A. Cruz

    2016-01-01

    Full Text Available This paper reviews recent advances in graphene-based biosensors development in order to obtain smaller and more portable devices with better performance for earlier cancer detection. In fact, the potential of Graphene for sensitive detection and chemical/biological free-label applications results from its exceptional physicochemical properties such as high electrical and thermal conductivity, aspect-ratio, optical transparency and remarkable mechanical and chemical stability. Herein we start by providing a general overview of the types of graphene and its derivatives, briefly describing the synthesis procedure and main properties. It follows the reference to different routes to engineer the graphene surface for sensing applications with organic biomolecules and nanoparticles for the development of advanced biosensing platforms able to detect/quantify the characteristic cancer biomolecules in biological fluids or overexpressed on cancerous cells surface with elevated sensitivity, selectivity and stability. We then describe the application of graphene in optical imaging methods such as photoluminescence and Raman imaging, electrochemical sensors for enzymatic biosensing, DNA sensing, and immunosensing. The bioquantification of cancer biomarkers and cells is finally discussed, particularly electrochemical methods such as voltammetry and amperometry which are generally adopted transducing techniques for the development of graphene based sensors for biosensing due to their simplicity, high sensitivity and low-cost. To close, we discuss the major challenges that graphene based biosensors must overcome in order to reach the necessary standards for the early detection of cancer biomarkers by providing reliable information about the patient disease stage.

  5. Graphene: The Missing Piece for Cancer Diagnosis?

    Science.gov (United States)

    Cruz, Sandra M A; Girão, André F; Gonçalves, Gil; Marques, Paula A A P

    2016-01-21

    This paper reviews recent advances in graphene-based biosensors development in order to obtain smaller and more portable devices with better performance for earlier cancer detection. In fact, the potential of Graphene for sensitive detection and chemical/biological free-label applications results from its exceptional physicochemical properties such as high electrical and thermal conductivity, aspect-ratio, optical transparency and remarkable mechanical and chemical stability. Herein we start by providing a general overview of the types of graphene and its derivatives, briefly describing the synthesis procedure and main properties. It follows the reference to different routes to engineer the graphene surface for sensing applications with organic biomolecules and nanoparticles for the development of advanced biosensing platforms able to detect/quantify the characteristic cancer biomolecules in biological fluids or overexpressed on cancerous cells surface with elevated sensitivity, selectivity and stability. We then describe the application of graphene in optical imaging methods such as photoluminescence and Raman imaging, electrochemical sensors for enzymatic biosensing, DNA sensing, and immunosensing. The bioquantification of cancer biomarkers and cells is finally discussed, particularly electrochemical methods such as voltammetry and amperometry which are generally adopted transducing techniques for the development of graphene based sensors for biosensing due to their simplicity, high sensitivity and low-cost. To close, we discuss the major challenges that graphene based biosensors must overcome in order to reach the necessary standards for the early detection of cancer biomarkers by providing reliable information about the patient disease stage.

  6. Defensins, lectins, mucins, and secretory immunoglobulin A: microbe-binding biomolecules that contribute to mucosal immunity in the human gut.

    Science.gov (United States)

    Chairatana, Phoom; Nolan, Elizabeth M

    2017-02-01

    In the intestine, the mucosal immune system plays essential roles in maintaining homeostasis between the host and microorganisms, and protecting the host from pathogenic invaders. Epithelial cells produce and release a variety of biomolecules into the mucosa and lumen that contribute to immunity. In this review, we focus on a subset of these remarkable host-defense factors - enteric α-defensins, select lectins, mucins, and secretory immunoglobulin A - that have the capacity to bind microbes and thereby contribute to barrier function in the human gut. We provide an overview of the intestinal epithelium, describe specialized secretory cells named Paneth cells, and summarize our current understanding of the biophysical and functional properties of these select microbe-binding biomolecules. We intend for this compilation to complement prior reviews on intestinal host-defense factors, highlight recent advances in the field, and motivate investigations that further illuminate molecular mechanisms as well as the interplay between these molecules and microbes.

  7. Proteopedia: a status report on the collaborative, 3D web-encyclopedia of proteins and other biomolecules.

    Science.gov (United States)

    Prilusky, Jaime; Hodis, Eran; Canner, David; Decatur, Wayne A; Oberholser, Karl; Martz, Eric; Berchanski, Alexander; Harel, Michal; Sussman, Joel L

    2011-08-01

    Proteopedia is a collaborative, 3D web-encyclopedia of protein, nucleic acid and other biomolecule structures. Created as a means for communicating biomolecule structures to a diverse scientific audience, Proteopedia (http://www.proteopedia.org) presents structural annotation in an intuitive, interactive format and allows members of the scientific community to easily contribute their own annotations. Here, we provide a status report on Proteopedia by describing advances in the web resource since its inception three and a half years ago, focusing on features of potential direct use to the scientific community. We discuss its progress as a collaborative 3D-encyclopedia of structures as well as its use as a complement to scientific publications and PowerPoint presentations. We also describe Proteopedia's use for 3D visualization in structure-related pedagogy.

  8. EFFECT OF CARBOFURAN ON THE FORMATION OF SOME BIOMOLECULES IN BRINJAL (SOLANUM MELONGENA L. LEAF

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    MANZOOR A, ASHRAFI

    2014-09-01

    Full Text Available The present work was carried out with the objective to study the effect of carbofuran on the quantitative formation of carbohydrate, total free amino acids, protein, total phenol and total chlorophyll contents in brinjal leaf as recorded on 1, 7, 14, 21, 28 and 35 days after application (DAA. The carbohydrate content decreased to the extent of 3.36, 4.53 and 4.60% respectively against control (T1 : 0, recommended (T2 : 33.0 kg ha–1 and double of recommended (T3 : 66.0 kg ha–1 doses of carbofuran formulation on the 35th DAA in comparison with 1st DAA. The total free amino acid content decreased to 42.82, 45.84 and 49.89% respectively against the above doses. In case of protein content also an overall decrease of 45.28, 43.10 and 45.61% with regards to 1st DAA was observed. The total phenol content, on the contrary, recorded an increase of 18.85, 21.77 and 5.35% respectively in case of above three doses. The total chlorophyll content again exhibited a decrease of 20.99, 22.73 and 36.05% respectively. So the formation of all the biomolecules under study except phenol in brinjal leaf was found to decrease with passage of time as an effect of application of carbofuran.

  9. Biotin-Streptavidin Competition Mediates Sensitive Detection of Biomolecules in Enzyme Linked Immunosorbent Assay.

    Science.gov (United States)

    Lakshmipriya, Thangavel; Gopinath, Subash C B; Tang, Thean-Hock

    2016-01-01

    Enzyme Linked Immunosorbent Assay (ELISA) is the gold standard assay for detecting and identifying biomolecules using antibodies as the probe. Improving ELISA is crucial for detecting disease-causing agents and facilitating diagnosis at the early stages of disease. Biotinylated antibody and streptavidin-conjugated horse radish peroxide (streptavidin-HRP) often are used with ELISA to enhance the detection of various kinds of targets. In the present study, we used a competition-based strategy in which we pre-mixed free biotin with streptavidin-HRP to generate high-performance system, as free biotin occupies some of the biotin binding sites on streptavidin, thereby providing more chances for streptavidin-HRP to bind with biotinylated antibody. ESAT-6, which is a protein secreted early during tuberculosis infection, was used as the model target. We found that 8 fM of free biotin mixed with streptavidin-HRP anchored the higher detection level of ESAT-6 by four-fold compared with detection without free biotin (only streptavidin-HRP), and the limit of detection of the new method was 250 pM. These results suggest that biotin-streptavidin competition can be used to improve the diagnosis of analytes in other types of sensors.

  10. Unconstrained Enhanced Sampling for Free Energy Calculations of Biomolecules: A Review.

    Science.gov (United States)

    Miao, Yinglong; McCammon, J Andrew

    Free energy calculations are central to understanding the structure, dynamics and function of biomolecules. Yet insufficient sampling of biomolecular configurations is often regarded as one of the main sources of error. Many enhanced sampling techniques have been developed to address this issue. Notably, enhanced sampling methods based on biasing collective variables (CVs), including the widely used umbrella sampling, adaptive biasing force and metadynamics, have been discussed in a recent excellent review (Abrams and Bussi, Entropy, 2014). Here, we aim to review enhanced sampling methods that do not require predefined system-dependent CVs for biomolecular simulations and as such do not suffer from the hidden energy barrier problem as encountered in the CV-biasing methods. These methods include, but are not limited to, replica exchange/parallel tempering, self-guided molecular/Langevin dynamics, essential energy space random walk and accelerated molecular dynamics. While it is overwhelming to describe all details of each method, we provide a summary of the methods along with the applications and offer our perspectives. We conclude with challenges and prospects of the unconstrained enhanced sampling methods for accurate biomolecular free energy calculations.

  11. A Practical Quantum Mechanics Molecular Mechanics Method for the Dynamical Study of Reactions in Biomolecules.

    Science.gov (United States)

    Mendieta-Moreno, Jesús I; Marcos-Alcalde, Iñigo; Trabada, Daniel G; Gómez-Puertas, Paulino; Ortega, José; Mendieta, Jesús

    2015-01-01

    Quantum mechanics/molecular mechanics (QM/MM) methods are excellent tools for the modeling of biomolecular reactions. Recently, we have implemented a new QM/MM method (Fireball/Amber), which combines an efficient density functional theory method (Fireball) and a well-recognized molecular dynamics package (Amber), offering an excellent balance between accuracy and sampling capabilities. Here, we present a detailed explanation of the Fireball method and Fireball/Amber implementation. We also discuss how this tool can be used to analyze reactions in biomolecules using steered molecular dynamics simulations. The potential of this approach is shown by the analysis of a reaction catalyzed by the enzyme triose-phosphate isomerase (TIM). The conformational space and energetic landscape for this reaction are analyzed without a priori assumptions about the protonation states of the different residues during the reaction. The results offer a detailed description of the reaction and reveal some new features of the catalytic mechanism. In particular, we find a new reaction mechanism that is characterized by the intramolecular proton transfer from O1 to O2 and the simultaneous proton transfer from Glu 165 to C2.

  12. Magnetic molecularly imprinted polymer for the isolation and detection of biotin and biotinylated biomolecules.

    Science.gov (United States)

    Ben Aissa, A; Herrera-Chacon, A; Pupin, R R; Sotomayor, M D P T; Pividori, M I

    2017-02-15

    Magnetic separation based on biologically-modified magnetic particles is a preconcentration procedure commonly integrated in magneto actuated platforms for the detection of a huge range of targets. However, the main drawback of this material is the low stability and high cost. In this work, a novel hybrid molecularly-imprinted polymer with magnetic properties is presented with affinity towards biotin and biotinylated biomolecules. During the synthesis of the magneto core-shell particles, biotin was used as a template. The characterization of this material by microscopy techniques including SEM, TEM and confocal microscopy is presented. The application of the magnetic-MIPs for the detection of biotin and biotinylated DNA in magneto-actuated platforms is also described for the first time. The magnetic-MIP showed a significant immobilization capacity of biotinylated molecules, giving rise to a cheaper and a robust method (it is not required to be stored at 4°C) with high binding capacity for the separation and purification under magnetic actuation of a wide range of biotinylated molecules, and their downstream application including determination of their specific targets.

  13. Charging effect in Au nanoparticle memory device with biomolecule binding mechanism.

    Science.gov (United States)

    Jung, Sung Mok; Kim, Hyung-Jun; Kim, Bong-Jin; Yoon, Tae-Sik; Kim, Yong-Sang; Lee, Hyun Ho

    2011-07-01

    Organic memory device having gold nanoparticle (Au NPs) has been introduced in the structure of metal-pentacene-insulator-silicon (MPIS) capacitor device, where the Au NPs layer was formed by a new bonding method. Biomolecule binding mechanism between streptavidin and biotin was used as a strong binding method for the formation of monolayered Au NPs on polymeric dielectric of poly vinyl alcohol (PVA). The self-assembled Au NPs was functioned to show storages of charge in the MPIS device. The binding by streptavidin and biotin was confirmed by AFM and UV-VIS. The UV-VIS absorption of the Au NPs was varied at 515 nm and 525 nm depending on the coating of streptavidin. The AFM image showed no formation of multi-stacked layers of the streptavidin-capped Au NPs on biotin-NHS layer. Capacitance-voltage (C-V) performance of the memory device was measured to investigate the charging effect from Au NPs. In addition, charge retention by the Au NPs storage was tested to show 10,000 s in the C-V curve.

  14. N-Hydroxysuccinimide-terminated self-assembled monolayers on gold for biomolecules immobilisation

    Energy Technology Data Exchange (ETDEWEB)

    Cabrita, J.F. [Laboratorio de SPM, Faculdade de Ciencias da Universidade de Lisboa, Ed. ICAT, Campo Grande, 1749-016 Lisbon (Portugal); CQB, Departamento de Quimica e Bioquimica da Faculdade de Ciencias da Universidade de Lisboa, Campo Grande, 1749-016 Lisbon (Portugal); Abrantes, L.M. [Laboratorio de SPM, Faculdade de Ciencias da Universidade de Lisboa, Ed. ICAT, Campo Grande, 1749-016 Lisbon (Portugal); CQB, Departamento de Quimica e Bioquimica da Faculdade de Ciencias da Universidade de Lisboa, Campo Grande, 1749-016 Lisbon (Portugal); Viana, A.S. [Laboratorio de SPM, Faculdade de Ciencias da Universidade de Lisboa, Ed. ICAT, Campo Grande, 1749-016 Lisbon (Portugal)]. E-mail: anaviana@icat.fc.ul.pt

    2005-03-15

    Pure and mixed N-hydroxysuccinimide-terminated and butanethiol monolayers were prepared on flat gold (1 1 1) surfaces with the intent of developing suitable platforms for the direct biomolecules immobilisation. The self-assembled monolayers (SAMs) were characterised by electrochemical reductive desorption of the thiolate from the gold surface. The data have shown that certain solution proportions of the two compounds yield modified electrodes exhibiting intermediate electrochemical behaviour of the corresponding pure SAMs. The reactivity of the terminal N-hydroxysuccinimide (NHS) towards amine functionalities has been tested for the covalent attachment of Dopamine. The cyclic voltammetric responses of the investigated monolayers, after contacting with a Dopamine solution, have confirmed the chemical coupling of the amine as well as the formation of mixed SAMs. The Dopamine surface coverage increased with the amount of surface NHS. Laccase was also successfully immobilised onto this modified electrodes. The electrochemical behaviour of the modified SAMs with Laccase indicates direct electron transfer between the immobilised enzyme and the gold surface. Evidence for Laccase immobilisation was also provided by atomic force microscopic measurements.

  15. An improved Bathocuproine assay for accurate valence identification and quantification of copper bound by biomolecules.

    Science.gov (United States)

    Chen, Dinglong; Darabedian, Narek; Li, Zhiqiang; Kai, Tianhan; Jiang, Dianlu; Zhou, Feimeng

    2016-03-15

    Copper is an essential metal in all organisms. Reliably quantifying and identifying the copper content and oxidation state is crucial, since the information is essential to understanding protein structure and function. Chromophoric ligands, such as Bathocuproine (BC) and its water-soluble analog, Bathocuproinedisulfonic acid (BCS), preferentially bind Cu(I) over Cu(II), and therefore have been widely used as optical probes to determine the oxidation state of copper bound by biomolecules. However, the BCS assay is commonly misused, leading to erroneous conclusions regarding the role of copper in biological processes. By measuring the redox potential of Cu(II)-BCS2 and conducting UV-vis absorption measurements in the presence of oxidizable amino acids, the thermodynamic origin of the potential artifacts becomes evident. The BCS assay was improved by introducing a strong Cu(II) chelator EDTA prior to the addition of BCS to prevent interference that might arise from Cu(II) present in the sample. The strong Cu(II) chelator rids of all the potential errors inherent in the conventional BCS assay. Applications of the improved assay to peptides and protein containing oxidizable amino acid residues confirm that free Cu(II) no longer leads to artifacts, thereby resolving issues related to this persistently misused colorimetric assay of Cu(I) in biological systems.

  16. Optimization of extraction conditions for secondary biomolecules from various plant species

    Directory of Open Access Journals (Sweden)

    Šibul Filip S.

    2016-01-01

    Full Text Available Extraction of plant secondary metabolites is an essential step in isolation of natural products. Non-optimized extraction conditions can lead to losses, degradation and modification of the biomolecules. In this paper, the influence of different solvent mixtures, solvent amounts, temperature, extraction time, and procedures for defatting on yield and profile of various classes of secondary metabolites was investigated. Rumex alpinus was used for the extraction of anthraquinones, Glycine max for isoflavonoids, Chaerophyllum bulbosum for flavonoids and phenolic acids, Anthriscus sylvestris for lignans and coumarins, alkaloids were extracted from Lupinus albus and sesquiterpene lactones from Artemisia absinthium. Extraction efficiency was evaluated by use of LC-DAD-ESI-MS/MS. The compromise extraction solvent for all of the examined compounds is 80 % methanol, mixed in ratio 13 : 1 with plant material. Maceration should last for six hours, repeated four times with fresh solvent. Defatting of the extracts does not lead to significant losses of the compounds of interest. It is acceptable to use extraction and evaporation temperature of 60ºC, while the extracts should be stored in the dark, on -20ºC. [Projekat Ministarstva nauke Republike Srbije, br. 172058

  17. Molecular MRI in the Earth's Magnetic Field Using Continuous Hyperpolarization of a Biomolecule in Water.

    Science.gov (United States)

    Rovedo, Philipp; Knecht, Stephan; Bäumlisberger, Tim; Cremer, Anna Lena; Duckett, Simon B; Mewis, Ryan E; Green, Gary G R; Burns, Michael; Rayner, Peter J; Leibfritz, Dieter; Korvink, Jan G; Hennig, Jürgen; Pütz, Gerhard; von Elverfeldt, Dominik; Hövener, Jan-Bernd

    2016-06-30

    In this work, we illustrate a method to continuously hyperpolarize a biomolecule, nicotinamide, in water using parahydrogen and signal amplification by reversible exchange (SABRE). Building on the preparation procedure described recently by Truong et al. [ J. Phys. Chem. B , 2014 , 118 , 13882 - 13889 ], aqueous solutions of nicotinamide and an Ir-IMes catalyst were prepared for low-field NMR and MRI. The (1)H-polarization was continuously renewed and monitored by NMR experiments at 5.9 mT for more than 1000 s. The polarization achieved corresponds to that induced by a 46 T magnet (P = 1.6 × 10(-4)) or an enhancement of 10(4). The polarization persisted, although reduced, if cell culture medium (DPBS with Ca(2+) and Mg(2+)) or human cells (HL-60) were added, but was no longer observable after the addition of human blood. Using a portable MRI unit, fast (1)H-MRI was enabled by cycling the magnetic field between 5 mT and the Earth's field for hyperpolarization and imaging, respectively. A model describing the underlying spin physics was developed that revealed a polarization pattern depending on both contact time and magnetic field. Furthermore, the model predicts an opposite phase of the dihydrogen and substrate signal after one exchange, which is likely to result in the cancelation of some signal at low field.

  18. Biomolecule Analogues 2-Hydroxypyridine and 2-Pyridone Base Pairing on Ice Nanoparticles.

    Science.gov (United States)

    Rubovič, Peter; Pysanenko, Andriy; Lengyel, Jozef; Nachtigallová, Dana; Fárník, Michal

    2016-07-14

    Ice nanoparticles (H2O)N, N ≈ 450 generated in a molecular beam experiment pick up individual gas phase molecules of 2-hydroxypyridine and 2-pyridone (HP) evaporated in a pickup cell at temperatures between 298 and 343 K. The mass spectra of the doped nanoparticles show evidence for generation of clusters of adsorbed molecules (HP)n up to n = 8. The clusters are ionized either by 70 eV electrons or by two photons at 315 nm (3.94 eV). The two ionization methods yield different spectra, and their comparison provides an insight into the neutral cluster composition, ionization and intracluster ion-molecule reactions, and cluster fragmentation. Quite a few molecules were reported not to coagulate on ice nanoparticles previously. The (HP)n cluster generation on ice nanoparticles represents the first evidence for coagulating of molecules and cluster formation on free ice nanoparticles. For comparison, we investigate the coagulation of HP molecules picked up on large clusters ArN, N ≈ 205, and also (HP)n clusters generated in supersonic expansions with Ar buffer gas. This comparison points to a propensity for the (HP)2 dimer generation on ice nanoparticles. This shows the feasibility of base pairing for model of biological molecules on free ice nanoparticles. This result is important for hypotheses of the biomolecule synthesis on ice grains in the space. We support our findings by theoretical calculations that show, among others, the HP dimer structures on water clusters.

  19. The complete microspeciation of ovothiol A disulfide: a hexabasic symmetric biomolecule.

    Science.gov (United States)

    Mirzahosseini, Arash; Orgován, Gábor; Tóth, Gergő; Hosztafi, Sándor; Noszál, Béla

    2015-03-25

    The site-specific acid-base properties of ovothiol A disulfide (OvSSOv), the smallest hexabasic multifunctional biomolecule with complex interdependent moieties, were studied with (1)H NMR-pH and potentiometric titrations. The unprecedented complexity of the protonation microequilibria could be overcome by taking into account the mirror-image molecular symmetry, synthesizing and studying auxiliary model compounds and developing a custom-tailored evaluation method. The amino, imidazole, and carboxylate moieties are quantified in terms of 192 microscopic protonation constants and 64 microspecies, 96 and 36 of which are chemically different ones, respectively. Nine pairwise interactivity parameters also characterize the OvSSOv-proton system at the level of molecular subunits. These data allow understanding and influencing the co-dependent acid-base and redox properties of the highly complex OvSH-OvSSOv and related thiol-disulfide systems, which provide protection against oxidative stress. This work is the first complete microspeciation of a hexabasic molecule.

  20. Optimization of biomolecule separation by combining microscale filtration and design-of-experiment methods.

    Science.gov (United States)

    Kazemi, Amir S; Kawka, Karina; Latulippe, David R

    2016-10-01

    There is considerable interest in developing microscale (i.e., high-throughput) methods that enable multiple filtration experiments to be run in parallel with smaller sample amounts and thus reduce the overall required time and associated cost to run the filtration tests. Previous studies to date have focused on simply evaluating the filtration capacity, not the separation performance. In this work, the stirred-well filtration (SWF) method was used in combination with design-of-experiment (DOE) methods to optimize the separation performance for three binary mixtures of bio-molecules: protein-protein, protein-polysaccharide, and protein-DNA. Using the parallel based format of the SWF method, eight constant-flux ultrafiltration experiments were conducted at once to study the effects of stirring conditions, permeate flux, and/or solution conditions (pH, ionic strength). Four separate filtration tests were conducted for each combination of process variables; in total, over 100 separate tests were conducted. The sieving coefficient and selectivity results are presented to match the DOE design format and enable a greater understanding of the effects of the different process variables that were studied. The method described herein can be used to rapidly determine the optimal combination of process factors that give the best separation performance for a range of membrane-based separations applications and thus obviate the need to run a large number of traditional lab-scale tests. Biotechnol. Bioeng. 2016;113: 2131-2139. © 2016 Wiley Periodicals, Inc.

  1. Microfluidic paper-based biomolecule preconcentrator based on ion concentration polarization.

    Science.gov (United States)

    Han, Sung Il; Hwang, Kyo Seon; Kwak, Rhokyun; Lee, Jeong Hoon

    2016-06-21

    Microfluidic paper-based analytical devices (μPADs) for molecular detection have great potential in the field of point-of-care diagnostics. Currently, a critical problem being faced by μPADs is improving their detection sensitivity. Various preconcentration processes have been developed, but they still have complicated structures and fabrication processes to integrate into μPADs. To address this issue, we have developed a novel paper-based preconcentrator utilizing ion concentration polarization (ICP) with minimal addition on lateral-flow paper. The cation selective membrane (i.e., Nafion) is patterned on adhesive tape, and this tape is then attached to paper-based channels. When an electric field is applied across the Nafion, ICP is initiated to preconcentrate the biomolecules in the paper channel. Departing from previous paper-based preconcentrators, we maintain steady lateral fluid flow with the separated Nafion layer; as a result, fluorescent dyes and proteins (FITC-albumin and bovine serum albumin) are continuously delivered to the preconcentration zone, achieving high preconcentration performance up to 1000-fold. In addition, we demonstrate that the Nafion-patterned tape can be integrated with various geometries (multiplexed preconcentrator) and platforms (string and polymer microfluidic channel). This work would facilitate integration of various ICP devices, including preconcentrators, pH/concentration modulators, and micro mixers, with steady lateral flows in paper-based platforms.

  2. Synthesis and characterization of cysteine functionalized silver nanoparticles for biomolecule immobilization.

    Science.gov (United States)

    Upadhyay, Lata Sheo Bachan; Verma, Nishant

    2014-11-01

    A facile method for the aqueous phase synthesis of cysteine-functionalized silver nanoparticles by potato extract has been reported in the present work. These functionalized nanoparticles were then used for the covalent immobilization of a biomolecule, alkaline phosphatase, on its surface through carbodiimide coupling. Different reaction parameters such as cysteine concentration, reducing agent concentration, temperature, pH and reaction time were varied during the nanoparticles' formation, and their effects on plasmon resonance were studied using Ultraviolet-visible spectroscopy. Fourier transform infrared spectroscopy was used to confirm the surface modification of silver nanoparticles by cysteine and the particle size analysis was done using particle size analyzer, which showed the average nanoparticles' size of 61 nm for bare silver nanoparticles and 201 nm for the enzyme-immobilized nanoparticles. The synthesized nanoparticles were found to be highly efficient for the covalent immobilization of alkaline phosphatase on its surface and retained 67% of its initial enzyme activity (9.44 U/mg), with 75% binding efficiency. The shelf life of the enzyme-nanoparticle bioconjugates was found to be 60 days, with a 12% loss in the initial enzyme activity. With a simple synthesis strategy, high immobilization efficiency and enhanced stability, these enzyme-coated nanoparticles have the potential for further integration into the biosensor technology.

  3. N-acetyl-L-histidine, a Prominent Biomolecule in Brain and Eye of Poikilothermic Vertebrates.

    Science.gov (United States)

    Baslow, Morris H; Guilfoyle, David N

    2015-04-24

    N-acetyl-L-histidine (NAH) is a prominent biomolecule in brain, retina and lens of poikilothermic vertebrates. In fish lens, NAH exhibits an unusual compartmentalized metabolism. It is synthesized from L-histidine (His) and acetyl Co-enzyme A. However, NAH cannot be catabolized by lens cells. For its hydrolysis, NAH is exported to ocular fluid where a specific acylase cleaves His which is then actively taken up by lens and re-synthesized into NAH. This energy-dependent cycling suggested a pump mechanism operating at the lens/ocular fluid interface. Additional studies led to the hypothesis that NAH functioned as a molecular water pump (MWP) to maintain a highly dehydrated lens and avoid cataract formation. In this process, each NAH molecule released to ocular fluid down its gradient carries with it 33 molecules of bound water, effectively transporting the water against a water gradient. In ocular fluid the bound water is released for removal from the eye by the action of NAH acylase. In this paper, we demonstrate for the first time the identification of NAH in fish brain using proton magnetic resonance spectroscopy (MRS) and describe recent evidence supporting the NAH MWP hypothesis. Using MRS, we also document a phylogenetic transition in brain metabolism between poikilothermic and homeothermic vertebrates.

  4. Evaluation of zinc oxide nano-microtetrapods for biomolecule sensing applications

    Science.gov (United States)

    Zhao, Wei; Zhao, Yichen; Karlsson, Mikael; Wang, Qin; Toprak, Muhammet S.

    2015-12-01

    Zinc oxide tetrapods (ZnO-Ts) were synthesized by flame transport synthesis using Zn microparticles. This work herein reports a systematical study on the structural, optical and electrochemical properties of the ZnO-Ts. The morphology of the ZnO-Ts was confirmed by scanning electron microscopy (SEM) as joint structures of four nano-microstructured legs, of which the diameter of each leg is 0.7-2.2 μm in average from the tip to the stem. The ZnO-Ts were dispersed in glucose solution to study the luminescence as well as photocatalytic activity in a mimicked biological environment. The photoluminescence (PL) intensity in the ultraviolet (UV) region quenches with linear dependence to increased glucose concentration up to 4 mM. The ZnO-Ts were also attached with glucose oxidase (GOx) and over coated with a thin film of Nafion to form active layers for electrochemical glucose sensing. The attachment of GOx and coating of Nafion were confirmed by infrared spectroscopy (FT-IR). Furthermore, the current response of the active layers based on ZnO-Ts was investigated by cyclic voltammetry (CV) in various glucose concentrations. Stable current response of glucose was detected with linear dependence to glucose concentration up to 12 mM, which confirms the potential of ZnO-Ts for biomolecule sensing applications.

  5. Observation of adsorption behavior of biomolecules on ferroelectric crystal surfaces with polarization domain patterns

    Science.gov (United States)

    Nakayama, Tomoaki; Isobe, Akiko; Ogino, Toshio

    2016-08-01

    Lithium tantalate (LiTaO3) is one of the ferroelectric crystals that exhibit spontaneous polarization domain patterns on its surface. We observed the polarization-dependent adsorption of avidin molecules, which are positively charged in a buffer solution at pH 7.0, on LiTaO3 surfaces caused by electrostatic interaction at an electrostatic double layer using atomic force microscopy (AFM). Avidin adsorption in the buffer solution was confirmed by scratching the substrate surfaces using the AFM cantilever, and the adsorption patterns were found to depend on the avidin concentration. When KCl was added to the buffer solution to weaken the electrostatic double layer interaction between avidin molecules and LiTaO3 surfaces, adsorption domain patterns disappeared. From the comparison between the adsorption and chemically etched domain patterns, it was found that avidin molecule adsorption is enhanced on negatively polarized domains, indicating that surface polarization should be taken into account in observing biomolecule behaviors on ferroelectric crystals.

  6. The complete microspeciation of ovothiol A, the smallest octafarious antioxidant biomolecule.

    Science.gov (United States)

    Mirzahosseini, Arash; Orgován, Gábor; Hosztafi, Sándor; Noszál, Béla

    2014-04-01

    Ovothiol A, a small biomolecule with highly potent antioxidant capacity, and three newly synthesized derivatives were studied by (1)H NMR, (15)N NMR, UV-pH titrations, and a customized evaluation method. The omni-interactive imidazole, amino, carboxylate, and thiolate moieties of ovothiol A are quantified in terms of 32 microscopic protonation constants, the relative concentrations of 16 microspecies, 6 pairwise interactivity parameters, and 8 protonation shifts. The highest and lowest imidazole basicities differ by a record-breaking five orders of magnitude, and the predominant thiolate protonation constant is by far the smallest known thiolate logK value. The latter provides an indication as to why ovothiol A occurs naturally under deep-water circumstances only. Since thiolate basicities are in correlation with thiol-disulfide redox potentials, the eight different, fine-tunable thiolate basicities offer versatile and highly specific antioxidant capacities within one single molecular skeleton. This work is the first complete microspeciation of a tetrabasic, nonsymmetrical natural compound.

  7. Spatially controlled immobilisation of biomolecules: A complete approach in green chemistry

    Science.gov (United States)

    Grinenval, Eva; Nonglaton, Guillaume; Vinet, Françoise

    2014-01-01

    The development of 'green' sensors is a challenging task in the field of biomolecule sensing, for example in the detection of cardiac troponin-I (cTnI). In the present work a complete approach in green chemistry was developed to create chemically active patterns for the immobilisation of biological probes. This key technology is discussed on the basis of the twelve green chemistry principles, and is a combination of surface patterning by spotting and surface chemistries modified by molecular vapour deposition. The (1H,1H,2H,2H)-perfluorodecyltrichlorosilane (FDTS) was used as a novel anti-adsorption layer while the 3,4-epoxybutyltrimethoxysilane (EBTMOS) was used to immobilise probes. Oligonucleotides and the anti-cTnI antibody were studied. The spatially controlled immobilisation of probes was characterised by fluorescence. The demonstrated surface modification has broad applications in areas such as diagnostics and bio-chemical sensing. Moreover, the environmental impacts of surface patterning and surface chemistry were discussed from a 'greenness' point of view.

  8. A Universal Method for Fishing Target Proteins from Mixtures of Biomolecules using Isothermal Titration Calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, X.; Sun, Q; Kini, R; Sivaraman, J

    2008-01-01

    The most challenging tasks in biology include the identification of (1) the orphan receptor for a ligand, (2) the ligand for an orphan receptor protein, and (3) the target protein(s) for a given drug or a lead compound that are critical for the pharmacological or side effects. At present, several approaches are available, including cell- or animal-based assays, affinity labeling, solid-phase binding assays, surface plasmon resonance, and nuclear magnetic resonance. Most of these techniques are not easy to apply when the target protein is unknown and the compound is not amenable to labeling, chemical modification, or immobilization. Here we demonstrate a new universal method for fishing orphan target proteins from a complex mixture of biomolecules using isothermal titration calorimetry (ITC) as a tracking tool. We took snake venom, a crude mixture of several hundred proteins/peptides, as a model to demonstrate our proposed ITC method in tracking the isolation and purification of two distinct target proteins, a major component and a minor component. Identities of fished out target proteins were confirmed by amino acid sequencing and inhibition assays. This method has the potential to make a significant advancement in the area of identifying orphan target proteins and inhibitor screening in drug discovery and characterization.

  9. N-acetyl-l-histidine, a Prominent Biomolecule in Brain and Eye of Poikilothermic Vertebrates

    Directory of Open Access Journals (Sweden)

    Morris H. Baslow

    2015-04-01

    Full Text Available N-acetyl-l-histidine (NAH is a prominent biomolecule in brain, retina and lens of poikilothermic vertebrates. In fish lens, NAH exhibits an unusual compartmentalized metabolism. It is synthesized from L-histidine (His and acetyl Co-enzyme A. However, NAH cannot be catabolized by lens cells. For its hydrolysis, NAH is exported to ocular fluid where a specific acylase cleaves His which is then actively taken up by lens and re-synthesized into NAH. This energy-dependent cycling suggested a pump mechanism operating at the lens/ocular fluid interface. Additional studies led to the hypothesis that NAH functioned as a molecular water pump (MWP to maintain a highly dehydrated lens and avoid cataract formation. In this process, each NAH molecule released to ocular fluid down its gradient carries with it 33 molecules of bound water, effectively transporting the water against a water gradient. In ocular fluid the bound water is released for removal from the eye by the action of NAH acylase. In this paper, we demonstrate for the first time the identification of NAH in fish brain using proton magnetic resonance spectroscopy (MRS and describe recent evidence supporting the NAH MWP hypothesis. Using MRS, we also document a phylogenetic transition in brain metabolism between poikilothermic and homeothermic vertebrates.

  10. Photoemission study of metallic iron nanoparticles surface aging in biological fluids. Influence on biomolecules adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Canivet, L.; Denayer, F.O. [Université de Lille 2, Droit et Santé, 42 rue P. Duez, 59000 Lille (France); Champion, Y.; Cenedese, P. [CNRS-ICMPE, 2 rue H. Dunant, 94320 Thiais (France); Dubot, P., E-mail: pdubot@icmpe.cnrs.fr [CNRS-ICMPE, 2 rue H. Dunant, 94320 Thiais (France)

    2014-07-01

    Iron nanoparticles (nFe) prepared by vaporization and cryogenic condensation process (10–100 nm) has been exposed to Hank's balanced salt solution (HBSS) and the B-Ali cell growth fluids. These media can be used for cellular growth to study nFe penetration through cell membrane and its induced cytotoxicity. Surface chemistry of nFe exposed to such complex fluids has been characterized as the nanoparticles surface can be strongly changed by adsorption or corrosion processes before reaching intracellular medium. Particle size and surface chemistry have been characterized by scanning electron microscopy (SEM) and high-resolution X-ray photoelectron spectroscopy (HR-XPS). Exposition of nFe particles to growth and differentiation media leads to the formation of an oxy-hydroxide layer containing chlorinated species. We found that the passivated Fe{sub 2}O{sub 3} layer of the bare nFe particles is rapidly transformed into a thicker oxy-hydroxide layer that has a greater ability to adsorb molecular ions or ionic biomolecules like proteins or DNA.

  11. Modulation of graft architectures for enhancing hydrophobic interaction of biomolecules with thermoresponsive polymer-grafted surfaces.

    Science.gov (United States)

    Idota, Naokazu; Kikuchi, Akihiko; Kobayashi, Jun; Sakai, Kiyotaka; Okano, Teruo

    2012-11-01

    This paper describes the effects of graft architecture of poly(N-isopropylacrylamide) (PIPAAm) brush surfaces on thermoresponsive aqueous wettability changes and the temperature-dependent hydrophobic interaction of steroids in silica capillaries (I.D.: 50 μm). PIPAAm brushes were grafted onto glass substrates by surface-initiated atom transfer radical polymerization (ATRP) that is one of the living radical polymerization techniques. Increases in the graft density and chain length of PIPAAm brushes increased the hydration of polymer brushes, resulting in the increased hydrophilic properties of the surface below the transition temperature of PIPAAm at 32 °C. More hydrophobic surface properties were also observed on surfaces modified with the block copolymers of IPAAm and n-butyl methacrylate (BMA) than that with IPAAm homopolymer-grafted surfaces over the transition temperature. Using PBMA-b-PIPAAm-grafted silica capillaries, the baseline separation of steroids was successfully achieved by only changing temperature. The incorporation of hydrophobic PBMA chains in grafted PIPAAm enhanced the hydrophobic interaction with testosterone above the transition temperature. The surface modification of hydrophobicity-enhanced thermoresponsive polymers is a promising method for the preparation of thermoresponsive biointerfaces that can effectively modulated their biomolecule and cell adsorption with the wide dynamic range of hydrophilic/hydrophobic property change across the transition temperature.

  12. Reversibility of the interactions between a novel surfactant derived from lysine and biomolecules.

    Science.gov (United States)

    Martín, Victoria Isabel; Sarrión, Beatriz; López-López, Manuel; López-Cornejo, Pilar; Robina, Inmaculada; Moyá, María Luisa

    2015-11-01

    In this work the novel cationic surfactant derived from lysine (S)-5-acetamido-6-(dodecylamino)-N,N,N-trimethyl-6-oxohexan-1-ammonium chloride, LYCl, was prepared and the physicochemical characterization of its aqueous solutions was carried out. The binding of LYCl to bovine serum albumin, BSA, and to double stranded calf thymus DNA, ctDNA, was investigated using several techniques. Results show that LYCl binding to BSA is followed by a decrease in the α-helix content caused by the unfolding of the protein. LYCl association to ctDNA mainly occurs through groove binding and electrostatic interactions. These interactions cause morphological changes in the polynucleotide from an elongated coil structure to a more compact globular structure, resulting in the compaction of ctDNA. Addition of β-cyclodextrin, β-CD, to the BSA-LYCl and ctDNA-LYCl complexes is followed by the refolding of BSA and the decompaction of ctDNA. This can be explained by the ability of β-CD to hinder BSA-LYCl and ctDNA-LYCl interactions due to the stronger and more specific β-CD-LYCl hydrophobic interactions. The stoichiometry of the β-CD:LYCl inclusion complex and its formation equilibrium constant were determined in this work. The reported procedure using β-CD is an efficient way to refold proteins and to decompact DNA, after the morphological changes caused in the biomolecules by their interaction with cationic surfactants.

  13. Reduced and oxidised scytonemin: theoretical protocol for Raman spectroscopic identification of potential key biomolecules for astrobiology.

    Science.gov (United States)

    Varnali, Tereza; Edwards, Howell G M

    2014-01-03

    Scytonemin is an important UV-radiation protective biomolecule synthesised by extremophilic cyanobacteria in stressed terrestrial environments. Scytonemin and its reduced form have been both isolated experimentally and the Raman spectrum for scytonemin has been assigned and characterised experimentally both in extracts and in living extremophilic cyanobacterial colonies. Scytonemin is recognised as a key biomarker molecule for terrestrial organisms in stressed environments. We propose a new, theoretically plausible structure for oxidised scytonemin which has not been mentioned in the literature hitherto. DFT calculations for scytonemin, reduced scytonemin and the new structure modelled and proposed for oxidised scytonemin are reported along with their Raman spectroscopic data and λmax UV-absorption data obtained theoretically. Comparison of the vibrational spectroscopic assignments allows the three forms of scytonemin to be detected and identified and assist not only in the clarification of the major features in the experimentally observed Raman spectral data for the parent scytonemin but also support a protocol proposed for their analytical discrimination. The results of this study provide a basis for the search for molecules of this type in future astrobiological missions of exploration and the search for extinct and extant life terrestrially.

  14. Sexual Health Information Seeking Online Among Runaway and Homeless Youth.

    Science.gov (United States)

    Barman-Adhikari, Anamika; Rice, Eric

    2011-06-01

    Research shows runaway and homeless youth are reluctant to seek help from traditional health providers. The Internet can be useful in engaging this population and meeting their needs for sexual health information, including information about HIV and other sexually transmitted infections (STIs). Using a sample of homeless youth living in Los Angeles, California in June 2009, this study assesses the frequency with which runaway and homeless youth seek sexual health information via the Internet, and assesses which youth are more likely to engage in seeking health information from online sources. Drawing from Andersen's (1968) health behavior model and Pescosolido's (1992) network episode model, we develop and refine a model for seeking online sexual health information among homeless youth. Rather than testing the predicative strength of a given model, our aim is to identify and explore conceptually driven correlates that may shed light on the characteristics associated with these help seeking behaviors among homeless youth. Analyses using multivariate logistic regression models reveal that among the sample of youth, females and gay males most frequently seek sexual health information online. We demonstrate the structure of social network ties (e.g., connection with parents) and the content of interactions (e.g., e-mail forwards of health information) across ties are critical correlates of online sexual health information seeking. Results show a continued connection with parents via the Internet is significantly associated with youth seeking HIV or STI information. Similarly for content of interactions, more youth who were sent health information online also reported seeking HIV information and HIV-testing information. We discuss implications for intervention and practice, focusing on how the Internet may be used for dissemination of sexual health information and as a resource for social workers to link transient, runaway, and homeless youth to care.

  15. Natural-origin polymers as carriers and scaffolds for biomolecules and cell delivery in tissue engineering applications

    OpenAIRE

    Malafaya, P.B.; G.A. Silva; Reis, R. L.

    2007-01-01

    The present paper intends to overview a wide range of natural–origin polymers with special focus on proteins and polysaccharides (the systems more inspired on the extracellular matrix) that are being used in research, or might be potentially useful as carriers systems for active biomolecules or as cell carriers with application in the tissue engineering field targeting several biological tissues. The combination of both applications into a single material has proven to be very challe...

  16. Procedures and Collaborative Information Seeking: A Study of Emergency Departments

    DEFF Research Database (Denmark)

    Hertzum, Morten; Reddy, Madhu

    2015-01-01

    Information seeking is a central and inherently collaborative activity in the emergency department (ED) which is the common entry point to hospitals for nearly all acute patients. In this paper, we investigate how ED clinicians’ collabo-rative information seeking (CIS) is shaped by the procedures...... that the clinicians follow in the ED. Based on observations in two Danish EDs, we identify four pro-cedures prominent to how CIS is accomplished: the triage procedure, the timeouts, the coordinating nurse, and the recurrent opportunities for information seeking at the whiteboard. We then discuss how CIS activities...

  17. Colon Cancer Biomarkers To Identify Patients Suitable For Therapeutic Intervention | NCI Technology Transfer Center | TTC

    Science.gov (United States)

    The National Cancer Institute's Laboratory of Human Carcinogenesis is seeking statements of capability or interest from parties interested in collaborative research to further develop, evaluate, or commercialize cancer biomarkers and therapeutic targets.

  18. Preparation and characterization of fluorophenylboronic acid-functionalized affinity monolithic columns for the selective enrichment of cis-diol-containing biomolecules.

    Science.gov (United States)

    Li, Qianjin; Liu, Zhen

    2015-01-01

    Boronate affinity monolithic columns have been developed into an important means for the selective recognition and capture of cis-diol-containing biomolecules, such as glycoproteins, nucleosides and saccharides. The ligands of boronic acids are playing an important role in boronate affinity monolithic columns. Although several boronate affinity monoliths with high affinity toward cis-diol-containing biomolecules have been reported, only few publications are focused on their detailed procedures for preparation and characterization. This chapter describes in detail the preparation and characterization of a boronate affinity monolithic column applying 2,4-difluoro-3-formyl-phenylboronic acid (DFFPBA) as a ligand. The DFFPBA-functionalized monolithic column not only exhibited an ultrahigh boronate affinity toward cis-diol-containing biomolecules, but also showed great potential for the selective enrichment of cis-diol-containing biomolecules in real samples.

  19. Correction: Kousholt, A.N. et al. Pathways for Genome Integrity in G2 Phase of the Cell Cycle. Biomolecules 2012, 2, 579-607.

    Science.gov (United States)

    Kousholt, Arne Nedergaard; Menzel, Tobias; Sørensen, Claus Storgaard

    2013-01-15

    We have discovered an error in our paper published in Biomolecules [1], in Figure 1 on page 589. The protein names ATR and ATRIP have been swapped. A corrected version of the Figure 1 is provided below. [...].

  20. Side-by-Side Comparison of Commonly Used Biomolecules That Differ in Size and Affinity on Tumor Uptake and Internalization.

    Directory of Open Access Journals (Sweden)

    Jeerapond Leelawattanachai

    Full Text Available The ability to use a systemically injected agent to image tumor is influenced by tumor characteristics such as permeability and vascularity, and the size, shape, and affinity of the imaging agent. In this study, six different imaging biomolecules, with or without specificity to tumor, were examined for tumor uptake and internalization at the whole body, ex-vivo tissue, and cellular levels: antibodies, antibody fragments (Fab, serum albumin, and streptavidin. The time of peak tumor uptake was dependent solely on the size of molecules, suggesting that molecular size is the major factor that influences tumor uptake by its effect on systemic clearance and diffusion into tumor. Affinity to tumor antigen failed to augment tumor uptake of Fab above non-specific accumulation, which suggests that Fab fragments of typical monoclonal antibodies may fall below an affinity threshold for use as molecular imaging agents. Despite abundant localization into the tumor, albumin and streptavidin were not found on cell surface or inside cells. By comparing biomolecules differing in size and affinity, our study highlights that while pharmacokinetics are a dominant factor in tumor uptake for biomolecules, affinity to tumor antigen is required for tumor binding and internalization.