WorldWideScience

Sample records for cancer seeking biomolecules

  1. Development of radioactively labeled cancer seeking biomolecules for targeted radiotherapy

    International Nuclear Information System (INIS)

    As meanwhile demonstrated by different groups a variety of human tumours express a large number of peptide receptors with a high affinity for VIP and SST. Radiolabeled synthetic analogs of this peptide hormones have been shown to be effective in diagnosis of SST receptor positive tumours and metastases. This fact seems to be a promising starting point for the therapeutic use of this cancer seeking tracer molecules for targeted radiotherapy. In this project we have focused our work on the preparation of DOTA-Lanreotide (Mauritius), a novel SST analog, which shows a high affinity to several SST receptors expressed by neuroendocrine tumours. This radiolabeled tracer actually is under evaluation by a European multicenter study for its diagnostic and therapeutic capacity

  2. Development of radioactively labeled cancer seeking biomolecules for targeted radiotherapy. Austria

    International Nuclear Information System (INIS)

    As meanwhile demonstrated by different groups, a variety of human tumours express a large number of peptide receptors with a high affinity for VIP and SST. Radiolabeled synthetic analogs of these peptide hormones have been shown to be effective in diagnosis of SST receptor positive tumours and metastases. This fact seems to be a promising starting point for the therapeutic use of this cancer seeking tracer molecules for targeted radiotherapy. In this project we have focused our work on the preparation of DOTA-Lanreotide (Mauritius), a novel SST analog, which shows a high affinity to several SST receptors expressed by neuroendocrine tumours. This radiolabeled tracer actually is under evaluation by a European multicenter study for its diagnostic and therapeutic capacity

  3. 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.

  4. Why Cancer Patients Seek Islamic Healing.

    Science.gov (United States)

    Suhami, Norhasmilia; Muhamad, Mazanah Bt; Krauss, Steven Eric

    2016-10-01

    Islamic healing is frequently referred to as the treatment of choice by many Muslim cancer patients in Malaysia. Despite its widespread use, there is limited information relating to patients' healing preferences. With rising cancer rates in the country, this issue has become a concern to public health policy makers. The purpose of this study was to understand why cancer patients seek Islamic healing. This qualitative study utilized in-depth interviews with 18 cancer patients. The findings indicate three main reasons: (1) recommendations from family, friends and doctors; (2) belief in Islamic healing and (3) the perceived ineffectiveness and dissatisfaction with conventional treatments. Islamic healing will likely continue to be popular complementary cancer treatment in Malaysia as it is grounded in strong cultural and religious beliefs. PMID:26391242

  5. Why Breast Cancer Patients Seek Traditional Healers

    Directory of Open Access Journals (Sweden)

    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.

  6. Why Breast Cancer Patients Seek Traditional Healers

    International Nuclear Information System (INIS)

    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

  7. Radiolabeled biomolecules for early cancer detection and therapy via angiogenesis targeting

    Energy Technology Data Exchange (ETDEWEB)

    Bouziotis, P. [Institute of Radioisotopes-Radiodiagnostic Products, N.C.S.R. ' Demokritos' , 153 10 Athens, Hellas (Greece)]. E-mail: pennybil@yahoo.gr; Psimadas, D. [Institute of Radioisotopes-Radiodiagnostic Products, N.C.S.R. ' Demokritos' , 153 10 Athens, Hellas (Greece): Biomedica Life Sciences SA, Athens, Hellas (Greece); Fani, M. [Institute of Radioisotopes-Radiodiagnostic Products, N.C.S.R. ' Demokritos' , 153 10 Athens, Hellas (Greece): Biomedica Life Sciences SA, Athens, Hellas (Greece); Gourni, E. [Institute of Radioisotopes-Radiodiagnostic Products, N.C.S.R. ' Demokritos' , 153 10 Athens, Hellas (Greece); Loudos, G. [Biomedical Simulations and Imaging Laboratory, N.T.U.A., Athens, Hellas (Greece); Xanthopoulos, S. [Institute of Radioisotopes-Radiodiagnostic Products, N.C.S.R. ' Demokritos' , 153 10 Athens, Hellas (Greece); Archimandritis, S.C. [Institute of Radioisotopes-Radiodiagnostic Products, N.C.S.R. ' Demokritos' , 153 10 Athens, Hellas (Greece); Varvarigou, A.D. [Institute of Radioisotopes-Radiodiagnostic Products, N.C.S.R. ' Demokritos' , 153 10 Athens, Hellas (Greece)

    2006-12-20

    Tumors cannot grow or metastasize without the formation of new blood vessels, i.e. without angiogenesis. A variety of anti-angiogenic agents leading to angiogenesis inhibition are in the clinical trial phase, among which are: (i) molecules which inhibit the action of Vascular Endothelial Growth Factors, VEGF and (ii) molecules which obstruct migration, differentiation and proliferation of endothelial cells, via their binding to receptors of the {alpha}{sub {nu}}{beta}{sub 3} integrins. Certain derivatives of the abovementioned categories, labeled with radionuclides, which emit {gamma}-radiation or {beta}-particles or positrons, have been proposed and are being evaluated as possible radiopharmaceuticals, for the detection and/or treatment of primary or metastatic cancer at an early stage. For the study of angiogenesis the following have been described: (a) antibodies targeting VEGF, labeled with radionuclides emitting {beta}- and/or {gamma}-radiation, which can be applied for the diagnosis and, possibly, for the treatment of cancer (b) peptide derivatives which contain the amino-acid sequence RGD (Arg-Gly-Asp) and compete for the {alpha}{sub {nu}}{beta}{sub 3} integrins, with the proteins of the stroma. It has been found that these radiolabeled biomolecules localize in tumors and can be used for the visualization and, possibly, for tumor eradication of primary and metastatic cancer. In our laboratory radiolabeling of biomolecules by beta and/or gamma emitters is a principal research goal. In the present work we are presenting our results on the labeling of monoclonal antibodies and peptides with {beta}- and {gamma}-emitting isotopes, as well as on their in vivo evaluation in experimental animal models, by use of specially dedicated imaging devices.

  8. Why Breast Cancer Patients Seek Traditional Healers

    OpenAIRE

    Mazanah Muhamad; Sharan Merriam; Norhasmilia Suhami

    2011-01-01

    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 ...

  9. Symptom Interpretation and Health Care Seeking in Ovarian Cancer

    DEFF Research Database (Denmark)

    Seibæk, L.; Petersen, L. K.; Blaakaer, J.;

    2011-01-01

    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...

  10. Cancer-Related Information Seeking Among Cancer Survivors: Trends Over a Decade (2003-2013).

    Science.gov (United States)

    Finney Rutten, Lila J; Agunwamba, Amenah A; Wilson, Patrick; Chawla, Neetu; Vieux, Sana; Blanch-Hartigan, Danielle; Arora, Neeraj K; Blake, Kelly; Hesse, Bradford W

    2016-06-01

    The demonstrated benefits of information seeking for cancer patients, coupled with increases in information availability, underscore the importance of monitoring patient information seeking experiences over time. We compared information seeking among cancer survivors to those with a family history of cancer and those with no history of cancer. We identified characteristics associated with greater information seeking among cancer survivors, key sources of cancer-related information, and changes in information source use over time. Data from five iterations of the Health Information National Trends Survey (HINTS) spanning 2003 to 2013 were merged and analyzed. Frequencies, cross-tabulations, multivariate logistic regression, and multinomial regression analyses were conducted. All data were weighted to provide representative estimates of the adult US population. Cancer information seeking was reported most frequently by cancer survivors (69.8 %). The percentage of cancer survivors who reported information seeking increased from 66.8 % in 2003 to 80.8 % in 2013. Cancer information seeking was independently associated with age, education, and income; seeking was less likely among older adults, those with less education, and those with lower incomes. Compared to respondents in 2003, those in 2005 (odds ratio (OR) = 0.40, 95 % confidence interval (CI) = 0.24-0.65) and 2008 (OR = .43, 95 % CI = 0.26-0.70) were about half as likely to use the Internet as the first source of cancer information compared to a healthcare provider. Despite overall increases in cancer information seeking and access to health information from a variety of sources, healthcare providers remain a key source of health information for cancer survivors. PMID:25712202

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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.

  13. Symptom interpretation and health care seeking in ovarian cancer

    DEFF Research Database (Denmark)

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

    2011-01-01

    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...... 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...... 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...

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

    Science.gov (United States)

    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.

  15. Symptom interpretation and health care seeking in ovarian cancer

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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. PMID:27016087

  17. Cancer Information Seeking and Cancer-Related Health Outcomes: A Scoping Review of the Health Information National Trends Survey Literature.

    Science.gov (United States)

    Wigfall, Lisa T; Friedman, Daniela B

    2016-09-01

    Cancer is a leading cause of death among adults in the United States. Only 54% of U.S. adults reported seeking cancer information in 2014. Cancer information seeking has been positively associated with cancer-related health outcomes such as screening adherence. We conducted a scoping review of studies that used data from the Health Information National Trends Survey (HINTS) in order to examine cancer information seeking in depth and the relationship between cancer information seeking and cancer-related health outcomes. We searched five databases and the HINTS website. The search yielded a total of 274 article titles. After review of 114 de-duplicated titles, 66 abstracts, and 50 articles, 22 studies met inclusion criteria. Cancer information seeking was the outcome in only four studies. The other 18 studies focused on a cancer-related health outcome. Cancer beliefs, health knowledge, and information seeking experience were positive predictors of cancer information seeking. Cancer-related awareness, knowledge, beliefs, preventive behaviors, and screening adherence were higher among cancer information seekers. Results from this review can inform other research study designs and primary data collection focused on specific cancer sites or aimed at populations not represented or underrepresented in the HINTS data (e.g., minority populations, those with lower socioeconomic status). PMID:27466828

  18. 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. PMID:26377524

  19. 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.

  20. Medical Help-Seeking for Sexual Concerns in Prostate Cancer Survivors

    Directory of Open Access Journals (Sweden)

    Melissa K. Hyde, PhD

    2016-03-01

    Conclusion: The TPB has utility as a theoretical framework to understand prostate cancer survivors' sexual help-seeking decisions and may inform development of more effective interventions. Masculine beliefs were highly salient. Men who were more emotionally self-reliant and attributed greater importance to sex formed stronger help-seeking intentions. Subjective norm contributed most strongly to help-seeking intentions suggesting that health professionals/partners/peers have a key role as support mechanisms and components of psycho-sexual interventions.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    OpenAIRE

    Oshima Sumiko; Kisa Kengo; Terashita Takayoshi; Kawabata Hidenobu; Maezawa Masaji

    2013-01-01

    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 foc...

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

    Science.gov (United States)

    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.

  4. 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.

  5. Ethnic differences in cancer symptom awareness and barriers to seeking medical help in England

    OpenAIRE

    Niksic, Maja; Rachet, Bernard; Warburton, Fiona G; Forbes, Lindsay J.L.

    2016-01-01

    Background: Ethnic differences in cancer symptom awareness and barriers to seeking medical help in the English population are not fully understood. We aimed to quantify these differences, to help develop more effective health campaigns, tailored to the needs of different ethnic groups. Methods: Using a large national data set (n=38 492) of cross-sectional surveys that used the Cancer Research UK Cancer Awareness Measure, we examined how cancer symptom awareness and barriers varied by ethnicit...

  6. Men with cancer : psychosocial issues, health behaviours, coping and help seeking

    OpenAIRE

    Dale, Hannah

    2016-01-01

    Background: A range of factors contribute to men with cancer having worse mortality and morbidity rates than women. The research specifically focused on psychosocial issues and health behaviours in men with cancer, and factors affecting help seeking behaviour. Methods: A mixed-methods study recruited adult men with cancer in the East of Scotland. The quantitative cross-sectional study explored psychosocial issues, health behaviours, and desire for support. Data from the Scottish Longitudin...

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Intended care seeking for ovarian cancer symptoms among U.S. women.

    Science.gov (United States)

    Cooper, Crystale Purvis; Gelb, Cynthia A; Trivers, Katrina F; Stewart, Sherri L

    2016-06-01

    To investigate U.S. women's intended care seeking for symptoms associated with ovarian cancer, data from the 2012 HealthStyles Fall survey of U.S. adults were examined. Analyses were limited to women with no history of gynecologic cancer (N = 1726). Logistic regression models for intended care seeking within 2 weeks of symptom onset were developed. A minority of women recognized that unexplained pelvic or abdominal pain (29.9%), unexplained bloating (18.1%), and feeling full after eating a small amount of food (10.1%) can indicate ovarian cancer, and 31.1% mistakenly believed that the Papanicolaou (Pap) test screens for the disease. In the multivariate regression models, the most consistent, significant predictors (p educational efforts should emphasize that symptoms associated with ovarian cancer may also result from benign conditions. PMID:27419020

  11. The role of helplines in cancer care: intertwining emotional support with information or advice-seeking needs.

    Science.gov (United States)

    Ekberg, Katie; McDermott, Joanne; Moynihan, Clare; Brindle, Lucy; Little, Paul; Leydon, Geraldine M

    2014-01-01

    Helplines are core feature of the contemporary U.K. health care system, however little is known about callers' experiences of seeking cancer-related telephone help. Qualitative interviews were conducted with 32 cancer helpline callers. The findings suggest cancer helplines offer callers (1) time to discuss their issues, (2) anonymity, (3) convenience, and (4) an open outlet for anyone affected by cancer including family/friends. Further, the findings highlighted that callers' help-seeking behavior was multifaceted, with their psychosocial needs being intrinsically intertwined with their information or advice-seeking needs. The implications are discussed in relation to the role of cancer helplines in the healthcare system. PMID:24611530

  12. Cancer Information Seeking Behaviors of Korean American Women: A Mixed-Methods Study Using Surveys and Focus Group Interviews

    OpenAIRE

    Oh, KM; Jun, J; Zhao, X.; Kreps, GL; Lee, EE

    2015-01-01

    Copyright © Taylor & Francis Group, LLC 2015. Despite the high risk of cancer to the population, Korean Americans are known to have lower knowledge about cancer related information and a lower level of adherence to cancer prevention guidelines. This indicates the necessity of cancer interventions targeting the Korean American population. To reach this population effectively, it is imperative to understand Korean Americans cancer information seeking behaviors. This study (a) identified cancer ...

  13. 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;

    2016-01-01

    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...... in lung cancer in accordance with the PRISMA guidelines. In the eligible trials, pain relief was reported in 75% of the patients included in the studies. The onset of pain relief was seen within 1-5 weeks after treatment, lasting up to 6 months. However, the methodology in the included trials was poor...... of prior/concomitant analgaesics. Large randomised controlled trials are needed to clarify the efficacy of radionuclide treatment in lung cancer....

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

    Science.gov (United States)

    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…

  15. Associations between health care seeking and socioeconomic and demographic determinants among people reporting alarm symptoms of cancer

    DEFF Research Database (Denmark)

    Svendsen, Rikke P; Jarbol, Dorte E; Larsen, Pia V;

    2013-01-01

    Late diagnosis of cancer may partly be explained by the fact that some patients do not seek health care promptly when experiencing an alarm symptom. Socioeconomic and demographic differences exist concerning knowledge and awareness of cancer alarm symptoms in the general population and socioecono......Late diagnosis of cancer may partly be explained by the fact that some patients do not seek health care promptly when experiencing an alarm symptom. Socioeconomic and demographic differences exist concerning knowledge and awareness of cancer alarm symptoms in the general population...

  16. Antecedent Characteristics of Online Cancer Information Seeking Among Rural Breast Cancer Patients: An Application of the Cognitive-Social Health Information Processing (C-SHIP) Model

    OpenAIRE

    Shaw, Bret R.; DuBenske, Lori L.; Han, Jeong Yeob; Cofta-Woerpel, Ludmila; Bush, Nigel; Gustafson, David H.; McTavish, Fiona

    2008-01-01

    Little research has examined the antecedent characteristics of patients most likely to seek online cancer information. This study employs the Cognitive-Social Health Information Processing (C-SHIP) model as a framework to understand what psychosocial characteristics precede online cancer-related information seeking among rural breast cancer patients who often have fewer healthcare providers and limited local support services. Examining 144 patients who were provided free computer hardware, In...

  17. Ethnic differences in cancer symptom awareness and barriers to seeking medical help in England

    Science.gov (United States)

    Niksic, Maja; Rachet, Bernard; Warburton, Fiona G; Forbes, Lindsay J L

    2016-01-01

    Background: Ethnic differences in cancer symptom awareness and barriers to seeking medical help in the English population are not fully understood. We aimed to quantify these differences, to help develop more effective health campaigns, tailored to the needs of different ethnic groups. Methods: Using a large national data set (n=38 492) of cross-sectional surveys that used the Cancer Research UK Cancer Awareness Measure, we examined how cancer symptom awareness and barriers varied by ethnicity, controlling for socio-economic position, age and gender. Data were analysed using multivariable logistic regression. Results: Awareness of cancer symptoms was lower in minority ethnic groups than White participants, with the lowest awareness observed among Bangladeshis and Black Africans. Ethnic minorities were more likely than White British to report barriers to help-seeking. South Asians reported the highest emotional barriers, such as lack of confidence to talk to the doctor, and practical barriers, such as worry about many other things. The Irish were more likely than the White British to report practical barriers, such as being too busy to visit a doctor. White British participants were more likely than any other ethnic group to report that they would feel worried about wasting the doctor's time. Overall, Black Africans had the lowest barriers. All differences were statistically significant (P<0.01 level), after controlling for confounders. Conclusions: Our findings suggest the need for culturally sensitive and targeted health campaigns, focused on improving recognition of cancer symptoms among ethnic minorities. Campaigns should tackle the specific barriers prevalent in each ethnic group. PMID:27280638

  18. 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.

  19. Race/Ethnicity and Multiple Cancer Risk Factors among Individuals Seeking Smoking Cessation Treatment

    Science.gov (United States)

    Kendzor, Darla E.; Costello, Tracy J.; Li, Yisheng; Vidrine, Jennifer Irvin; Mazas, Carlos A.; Reitzel, Lorraine R.; Cinciripini, Paul M.; Cofta-Woerpel, Ludmila M.; Businelle, Michael S.; Wetter, David W.

    2016-01-01

    Smoking in combination with other behavioral risk factors is known to have a negative influence on health, and individuals who smoke typically engage in multiple risk behaviors. However, little is known about the clustering of risk behaviors among smokers of varying race/ethnicity. The purpose of this study was to examine patterns of cancer risk behaviors and to identify predictors of multiple risk behaviors in a racially/ethnically diverse sample of individuals seeking smoking cessation treatment. Overweight/obesity, at-risk alcohol consumption, and insufficient physical activity were measured in 424 smokers (African American, n = 144; Latino, n = 141; Caucasian, n = 139). Results indicated that 90% of participants reported behavioral cancer risk factors in addition to smoking. Approximately 70% of participants were overweight or obese, 48% engaged in at-risk drinking, and 27% were insufficiently physically active. Univariate analyses indicated that race/ethnicity, p culturally sensitive interventions that target multiple risk behaviors. PMID:18990734

  20. Does the number of cancer patients' close social ties affect cancer-related information seeking through communication efficacy? Testing a mediation model.

    Science.gov (United States)

    Lewis, Nehama; Martinez, Lourdes S

    2014-09-01

    This study addresses whether having a broad social network of close friends equips cancer patients with increased efficacy to engage in communication about their cancer, which then leads to an increased likelihood of patients actively seeking cancer-related information. Guided by the theory of motivated information management, the study also tests whether the effect of the number of close social ties on information seeking is mediated, in part, by communication efficacy. Results are based on data collected from a randomly drawn sample from the Pennsylvania Cancer Registry of 2,013 cancer patients who completed mail surveys in the Fall of 2006. Results are consistent with a cross-sectional mediation effect in which the number of close social ties in one's social network is positively associated with communication efficacy (b = .17, p = .001), which, in turn, is positively associated with cancer-related information seeking (b = .13, p < .001).

  1. Labelling of CTMP with technetium-99m as radiopharmaceutical for bone cancer seeking

    International Nuclear Information System (INIS)

    Radiopharmaceutical for bone cancer seeking was developed in variable compound labelled with technetium-99m, formally pyrophosphate compound and diphosphonate compound such as methylenediphosphonate (99mTc-MDP), hydroxyethylene diphosphonate (99mTc-HEDP) and hydroxy methylene diphosphonate (99mTc-HMDP). Either pyrophosphate or diphosphonate still unsatisfied to use as radiopharmaceutical for bone cancer seeking because the high accumulation in lever, muscle and blood. The compound of tetraaminotetraphosphonate groups have the higher affinity in bone because of four phosphonate and four amine groups. This experiment was done to label the compound group especially 1,4,8, 1-tetraazacyclotetradecyl-1,4,8,11-tetramethylene phosphonic acid (CTMP) with technetium-99m radionuclide. To obtain the maximal labelling result, some parameters such as pH, amount of SnCl2 reductor and ligan, time and temperature of reaction are optimized. The optimal condition obtained were pH of 4-6, 100 µg of SnCl2 reductor, 500 µg of CTMP ligand and labelling time of 10 minutes in boiling water or 30 minutes in room temperature, with labelling efficiency was >95 %. (author)

  2. Delay in seeking medical advice by breast cancer patients presenting with a breast lump

    International Nuclear Information System (INIS)

    Among the most commonly cited causes of delay in seeking medical advice by breast cancer females patients are ignorance, fear and fatalistic attitude. In a previous study we found that psychological factors played the major part in this delay. In Egypt, most of the patients realized the significance of the presence of a breast lump. This initiated us to study another 80 breast cancer female patients. At least four interviews with each patient were performed within six months by the treating oncologist. The time between the discovery of the lump and seeking medical consultation varied between a few hours and five years with a mean of eight months after four interviews while it was one month after the first interview. Fifty-five patients (68.7%) sought medical advice after more than three months of the discovery of the lump. Patients who were above 50 years of age delayed more than younger patients. The presence of a husband and the work of patients had no effect on the delay. It seems that high education did not prevent the procrastination. Most of the patients (90%) realized the significance of presence of a breast lump. Variations of fear - and not ignorance - were the main causes of delay. The fear of the socio-economic consequences of diagnosis of cancer, the incurability of the disease, pain and death were more prominent than the fear of disfigurement and mastectomy. Elderly patients had a more fatalistic outlook. We suggest that radiation oncologists should be involved in the studies of different aspects of this complicated problem. 14 refs

  3. Reasons for not seeking medical help for severe pelvic floor symptoms: a qualitative study in survivors of gynaecological cancer

    NARCIS (Netherlands)

    M.H. Hazewinkel; M.A.G. Sprangers; E.F. Taminiau-Bloem; J. van der Velden; M.P.M. Burger; J.P.W.R. Roovers

    2010-01-01

    OBJECTIVE: (1) To explore the reasons for not seeking help for severe pelvic floor symptoms after gynaecological cancer treatment. (2) To determine the willingness to undergo treatment for these symptoms. (3) To invite suggestions to improve outpatient care. DESIGN: Qualitative study using semistruc

  4. 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.

  5. A Comprehensive Model of Cancer-Related Information Seeking Applied to Magazines.

    Science.gov (United States)

    Johnson, J. David; Meischke, Hendrika

    1993-01-01

    Examines a comprehensive model of information seeking resulting from the synthesis of three theoretical research streams: the health belief model, uses and gratifications research, and a model of media exposure. Suggests that models of information seeking from mass media should focus on purely communicative factors. (RS)

  6. 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.

  7. A Time Series Analysis of Cancer-Related Information Seeking: Hints From the Health Information National Trends Survey (HINTS) 2003-2014.

    Science.gov (United States)

    Huerta, Timothy R; Walker, Daniel M; Johnson, Tyler; Ford, Eric W

    2016-09-01

    Recent technological changes, such as the growth of the Internet, have made cancer information widely available. However, it remains unknown whether changes in access have resulted in concomitant changes in information seeking behavior. Previous work explored the cancer information seeking behaviors of the general population using the 2003 Health Information National Trends Survey (HINTS). This article aims to reproduce, replicate, and extend that existing analysis using the original dataset and five additional iterations of HINTS (2007, 2011, 2012, 2013, 2014). This approach builds on the earlier work by quantifying the magnitude of change in information seeking behaviors. Bivariate comparison of the 2003 and 2014 data revealed very similar results; however, the multivariate model including all years of data indicated differences between the original and extended models: individuals age 65 and older were no longer less likely to seek cancer information than the 18-35 reference population, and Hispanics were also no longer less likely to be cancer information seekers. The results of our analysis indicate an overall shift in cancer information seeking behaviors and also illuminate the impact of increased Internet usage over the past decade, suggesting specific demographic groups that may benefit from cancer information seeking encouragement. PMID:27565190

  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. Patterns of seeking medical care among Egyptian breast cancer patients: relationship to late-stage presentation.

    Science.gov (United States)

    Mousa, Shimaa M; Seifeldin, Ibrahim A; Hablas, Ahmed; Elbana, Eman S; Soliman, Amr S

    2011-12-01

    Breast cancer is the most common cancer among Egyptian women, accounting for 37.6% of female tumors, and is often diagnosed at later stages. The objective of this study was to investigate breast cancer patient navigation through the health care system in the Nile Delta. Interviews were conducted with 163 newly diagnosed breast cancer patients at the Tanta Cancer Center (TCC), the major cancer center of the region. Patients described their medical care pathway from the initial symptom experienced until their arrival at TCC. Patients whose initial contact was with a general surgeon (OR: 7.6, 95% CI: 2.1, 27.6), primary care provider (OR: 12.2, 95% CI: 2.9, 51.0), or gynecologist (OR: 8.6, 95% CI: 1.4, 53.4) were significantly more likely to experience a delay in reaching the TCC as compared to those visiting a surgical oncologist. Overcoming health care system and patient navigation barriers in developing countries may reduce the time for breast cancer patients to reach a cancer center for early management. PMID:21807518

  10. 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. PMID:23320398

  11. Study: Blacks Are Less Likely to Seek Genetic Counseling to Assess Cancer Risk

    Science.gov (United States)

    Black Issues in Higher Education, 2005

    2005-01-01

    Black women with a family history of breast cancer are much less likely than Whites to get genetic counseling, in part because of the mistaken notion that the genetic form of the illness is a White woman's disease, researchers say. While breast cancer generally is more common among White women, some data suggest both races have similar rates of…

  12. Health seeking behavior for cervical cancer in Ethiopia: a qualitative study

    OpenAIRE

    Birhanu Zewdie; Abdissa Alemseged; Belachew Tefera; Deribew Amare; Segni Hailemariam; Tsu Vivien; Mulholland Kim; Russell Fiona M

    2012-01-01

    Abstract Background Although cervical cancer is a leading cause of cancer related morbidity and mortality among women in Ethiopia, there is lack of information regarding the perception of the community about the disease. Methods Focus group discussions were conducted with men, women, and community leaders in the rural settings of Jimma Zone southwest Ethiopia and in the capital city, Addis Ababa. Data were captured using voice recorders, and field notes were transcribed verbatim from the loca...

  13. A discrete choice experiment of preferences for genetic counselling among Jewish women seeking cancer genetics services

    OpenAIRE

    Peacock, S.; Apicella, C; Andrews, L; Tucker, K.; Bankier, A; Daly, M. B.; Hopper, J L

    2006-01-01

    To determine which aspects of breast cancer genetic counselling are important to Ashkenazi Jewish women, a discrete choice experiment was conducted. Participants consisted of 339 Australian Ashkenazi Jewish women who provided a blood sample for research used to test for Ashkenazi Jewish ancestral mutations in the genes BRCA1 and BRCA2, and were offered their genetic test result through a cancer genetics service. Main outcome measures were women's preferences for, and trade-offs between, the g...

  14. 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

  15. Socio-cultural influences on the help-seeking behavior of patients with cancer.

    OpenAIRE

    Corner, Jessica L; Brindle, Lucy A

    2010-01-01

    Abstract ABSTRACT This paper sets out to review the influence of social processes on the timing of diagnosis of cancer and to explore the potential for promoting earlier diagnosis by addressing social factors which influence symptom recognition and the diagnostic process. Social processes refer to the means by which culture and social organisation may impact on timely cancer diagnosis. The paper calls for concerted action around an important and developing research agenda that...

  16. 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

  17. Information Seeking and Intentions to Have Genetic Testing for Hereditary Cancers in Rural and Appalachian Kentuckians

    Science.gov (United States)

    Kelly, Kimberly M.; Andrews, James E; Case, Donald O.; Allard, Suzanne L.; Johnson, J. David

    2007-01-01

    Context: Research is limited regarding the potential of genetic testing for cancer risk in rural Appalachia. Purpose: This study examined perceptions of genetic testing in a population sample of Kentuckians, with a focus on Appalachian and rural differences. The goals were to examine cultural and psychosocial factors that may predict intentions to…

  18. 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. PMID:23979671

  19. Smartphone apps as a source of cancer information: changing trends in health information-seeking behavior.

    Science.gov (United States)

    Pandey, Ambarish; Hasan, Sayeedul; Dubey, Divyanshu; Sarangi, Sasmit

    2013-03-01

    There is an increased interest in smartphone applications as a tool for delivery of health-care information. There have been no studies which evaluated the availability and content of cancer-related smartphone applications. This study aims to identify and analyze cancer-related applications available on the Apple iTunes platform. The Apple iTunes store was searched for cancer-related smartphone applications on July 29, 2011. The content of the applications was analyzed for cost, type of information, validity, and involvement of health-care agencies. A total of 77 relevant applications were identified. There were 24.6 % apps uploaded by health-care agencies, and 36 % of the apps were aimed at health-care workers. Among the apps, 55.8 % provided scientifically validated data. The difference in scientific validity between the apps aimed at general population versus health-care professionals was statistically significant (P smartphone applications and encourage participation by health-care agencies to ensure patient safety. PMID:23275239

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

    OpenAIRE

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

    2014-01-01

    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...

  1. 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.

  2. 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

  3. 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.

    OpenAIRE

    Antonio DeRosa

    2013-01-01

    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 ...

  4. 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. PMID:27092867

  5. 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.

  6. Changes of Socio-demographic data of clients seeking genetic counseling for hereditary breast and ovarian cancer due to the “Angelina Jolie Effect”

    OpenAIRE

    Staudigl, Christine; Pfeiler, Georg; Hrauda, Katharina; Renz, Romana; Berger, Andreas; Lichtenschopf, Renate; Singer, Christian F.; Tea, Muy-Kheng M.

    2016-01-01

    Background The purpose of this study was to evaluate socio-demographic characteristics of clients claiming genetic counseling for hereditary breast and ovarian cancer (HBOC) in Austria. Furthermore, changes of these parameters before and after Angelina Jolie’s (AJ) disclosure of carrying a BRCA mutation were evaluated. Methods In this prospective, nonrandomized study 268 consecutive clients seeking genetic counseling for HBOC at the Medical University of Vienna, Department of Obstetrics and G...

  7. Expertise seeking

    DEFF Research Database (Denmark)

    Hertzum, Morten

    2014-01-01

    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...

  8. Magnetic GMI sensor for detection of biomolecules

    International Nuclear Information System (INIS)

    A magnetic sensor based on the giant magnetoimpedance (GMI) effect for the detection of biomolecules was made with a CoFeSiB amorphous magnetic microwire as sensing element. Using soft ferromagnetic cobalt microparticles and field sensitivities of the impedance of about 2.5%/A m-1 in the very low field region (less than 200 A m-1) at frequencies close to 10 MHz, a highly sensitive response was measured, appropriate for the detection of low biomolecule concentrations

  9. 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

  10. 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.

  11. 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. PMID:26882008

  12. 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.

  13. Reaction between protein radicals and other biomolecules

    DEFF Research Database (Denmark)

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

    2002-01-01

    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......)-activated immobilized horseradish peroxidase (im-HRP). Subsequently, each of the three different biomolecules was separately added to the BSA radicals, after removal of im-HRP by centrifugation. Electron spin resonance (ESR) spectroscopy showed that all three biomolecules quenched the BSA radicals....... 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...

  14. Functional health literacy in Spanish-speaking Latinas seeking breast cancer screening through the National Breast and Cervical Cancer Screening Program

    OpenAIRE

    Samantha Garbers; Karen Schmitt; Anne Marie Rappa; Mary Ann Chiasson

    2010-01-01

    Samantha Garbers1, Karen Schmitt2, Anne Marie Rappa2, Mary Ann Chiasson11Public Health Solutions, New York, NY, USA; 2Columbia University Breast Cancer Screening Program, New York, NY, USABackground: This analysis examines the association between functional health literacy and follow-up after mammography among women receiving breast cancer screening at a National Breast and Cervical Cancer Early Detection Program site in New York City that provides universal bilingual case management.Methods:...

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

    OpenAIRE

    White, Margaret A.; Verhoef, Marja J.; Davison, B.J.; 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...

  16. 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.

  17. 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 ca...

  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. Ionic strength independence of charge distributions in solvation of biomolecules

    OpenAIRE

    Virtanen, J. J.; Sosnick, T. R.; Freed, K. F.

    2014-01-01

    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...

  20. 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.

  1. Does Patients’ Attachment Style Affect their Help-Seeking in relation to Cancer-Related Symptoms? – project protocol

    DEFF Research Database (Denmark)

    Andersen, Christina Maar; Pedersen, Anette Fischer; Olesen, Frede;

    to be able to contribute as an explanatory model. This theory describes the evolutionary and developmental origin of patterns of close interpersonal relationships OBJECTIVE: The aims of the present project are to examine whether attachment styles in general practitioners as well as in their patients...... the patients’ first presentation of symptom to the doctor's referral to clarifying investigations at specialists or hospitals. Knowledge about psychological factors that may cause patient and doctor delay is limited, but will be essential in an intervention on preventing delay. The Attachment theory seems...... influence length of patient delay and doctor delay in patients diagnosed with cancer. Interactions between patients’ attachment styles and general practitioners’ attachment styles on patient and doctor delay will also be explored. METHODS: The project is a cross-sectional study based on registry data...

  2. Quantum dots and their interaction with biomolecules

    OpenAIRE

    Stanisavljević, Maja

    2015-01-01

    In this study CdTe QDs were synthetized via microwave irradiation method. Further they have been modified for purposes of their interaction with biomolecules using different conjugation approaches. Applied conjugation chemistries were non-specific interaction, streptavidin-biotin affinity. Glutathione modified CdTe QDs of 2 nm size were capable of non-specific interaction with major groove of DNA, while streptavidin modified CdTe QDs served as specific linker for biotinylated oligonucleotides...

  3. Immobilizing Biomolecules Near the Diffraction Limit

    DEFF Research Database (Denmark)

    Skovsen, Esben; Neves-Petersen, Maria Teresa; Kold, Ane;

    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 ca...... a substrate, which can be generated by a UV diffraction pattern. Such patterns can have sub-micron feature sizes and could therefore be of great relevance for present and future nanotechnological applications....

  4. Of Tangerines, Asparagus, and Nonprotein Biomolecules.

    Science.gov (United States)

    2016-05-19

    Every month the editors of Cell Chemical Biology bring you highlights of the most recent chemical biology literature. Our May 2016 selection includes a new method for labeling and visualizing nonprotein biomolecules using electron microscopy; a small molecule, originally found in tangerine peel, that regulates our circadian clock and helps with some of the metabolic pathologies associated with circadian rhythms; and a finding that asparagine is used as an amino acid exchanger in tumor cells. PMID:27203369

  5. Functional health literacy in Spanish-speaking Latinas seeking breast cancer screening through the National Breast and Cervical Cancer Screening Program

    Directory of Open Access Journals (Sweden)

    Samantha Garbers

    2009-03-01

    Full Text Available Samantha Garbers1, Karen Schmitt2, Anne Marie Rappa2, Mary Ann Chiasson11Public Health Solutions, New York, NY, USA; 2Columbia University Breast Cancer Screening Program, New York, NY, USABackground: This analysis examines the association between functional health literacy and follow-up after mammography among women receiving breast cancer screening at a National Breast and Cervical Cancer Early Detection Program site in New York City that provides universal bilingual case management.Methods: A total of 707 Latinas who spoke Spanish as their primary language completed a survey of health and demographic characteristics and the Test of Functional Health Literacy in Spanish (TOFHLA-S. Survey results were matched with clinical outcome data.Results: Among the survey participants, 98% were foreign-born and 99% had no health insurance. While the study found significant differences in access to health information and past screening behavior, women without adequate health literacy in Spanish were no less likely to receive clinical resolution of abnormal mammograms within 60 days (81.8% overall; n = 110 or to return for a repeat mammogram within 18 months (57.2% overall; n = 697. In fact, among those referred for a Pap test (n = 310, women without adequate health literacy were more likely to receive a Pap test within 60 days of their mammogram than those with adequate health literacy (82% compared to 71%, OR: 1.83, 95% CI: 1.04–3.22.Discussion: The lack of significantly lower follow-up outcomes among women with inadequate and marginal functional health literacy in this population of primary Spanish-speaking Latinas suggests that, once women have accessed screening services, programmatic approaches may exist to mitigate barriers to follow-up and to ensure optimal cancer screening outcomes for women of all literacy levels.Keywords: health literacy, mammography, Latinas, case management, cancer screening

  6. 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. PMID:26990857

  7. 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.

  8. Communication and care in an acute cancer center: the effects of patients' willingness to communicate about health, health-care environment perceptions, and health status on information seeking, participation in care practices, and satisfaction.

    Science.gov (United States)

    Wright, Kevin B; Frey, Lawrence R

    2008-07-01

    This study investigated the role of willingness to communicate about health (WTCH) among older patients in a state-of-the-art cancer center. Specifically, relationships were examined between patients' WTCH and their information seeking, perceptions of coping activities the center offered, and satisfaction with the center. The study also explored how those relationships may be mediated by patients' perceptions of the health-care environment and their health status. The results indicated that WTCH may play an important role in predicting information-seeking behaviors, perceived helpfulness of center-sponsored activities, and overall satisfaction with care received at the center. Evidence also was found that perceptions of the health-care environment mediated cancer patients' WTCH. The implications of these findings for communication theory and application, as well as limitations and future directions for research, are discussed.

  9. 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.

  10. Cold atmospheric plasma sterilization: from bacteria to biomolecules

    Science.gov (United States)

    Kong, Michael

    2009-10-01

    Although ionized gases have been known to have biological effects for more than 100 years, their impact on the practice in healthcare service became very significant only recently. Today, plasma-based surgical tools are used for tissue reduction and blood coagulation as surgical procedures. Most significant however is the speed at which low-temperature gas plasmas are finding new applications in medicine and biology, including plasma sterilization, wound healing, and cancer therapies just to name a few. In the terminology of biotechnology, the ``pipeline'' is long and exciting. This presentation reviews the current status of the field with a particular emphasis on plasma inactivation of microorganisms and biomolecules, for which comprehensive scientific evidence has been obtained. Some of the early speculations of biocidal plasma species are now being confirmed through a combination of optical emission spectroscopy, laser-induced fluorescence, mass spectrometry, fluid simulation and biological sensing with mutated bacteria. Similarly, fundamental studies are being performed to examine cell components targeted by gas plasmas, from membrane, through lipid and membrane proteins, to DNA. Scientific challenge is significant, as the usual complexity of plasma dynamics and plasma chemistry is compounded by the added complication that cells are live and constantly evolving. Nevertheless, the current understanding of plasma inactivation currently provides strong momentum for plasma decontamination technologies to be realized in healthcare. We will discuss the issue of protein and tissue contaminations of surgical instruments and how cold atmospheric plasmas may be used to degrade and reduce their surface load. In the context of plasma interaction with biomolecules, we will consider recent data of plasma degradation of adhesion proteins of melanoma cells. These adhesion proteins are important for cancer cell migration and spread. If low-temperature plasmas could be used to

  11. 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

  12. Thermally modulated biomolecule transport through nanoconfined channels

    Science.gov (United States)

    Liu, Lei; Zhu, Lizhong

    2015-04-01

    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.

  13. 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.

  14. Bioconjugation and stabilisation of biomolecules in biosensors.

    Science.gov (United States)

    Liébana, Susana; Drago, Guido A

    2016-06-30

    Suitable bioconjugation strategies and stabilisation of biomolecules on electrodes is essential for the development of novel and commercially viable biosensors. In the present review, the functional groups that comprise the selectable targets for practical bioconjugation methods are discussed. We focus on describing the most common immobilisation techniques used in biosensor construction, which are classified into irreversible and reversible methods. Concerning the stability of proteins, the two main types of stability may be defined as (i) storage or shelf stability, and (ii) operational stability. Both types of stability are explained, as well as the introduction of an electrophoretic technique for predicting protein-polymer interactions. In addition, solution and dry stabilisation as well as stabilisation using the covalent immobilisation of proteins are discussed including possible factors that influence stability. Finally, the integration of nanomaterials, such as magnetic particles, with protein immobilisation is discussed in relation to protein stability studies. PMID:27365036

  15. Collaborative information seeking

    DEFF Research Database (Denmark)

    Hertzum, Morten

    2008-01-01

    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......, 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...... 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....

  16. 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. PMID:26432194

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

    Science.gov (United States)

    Virtanen, J J; Sosnick, T R; Freed, K F

    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. PMID:25494774

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. Cell and biomolecule delivery for regenerative medicine

    International Nuclear Information System (INIS)

    Regenerative medicine is an exciting field that aims to create regenerative alternatives to harvest tissues for transplantation. In this approach, the delivery of cells and biological molecules plays a central role. The scaffold (synthetic temporary extracellular matrix) delivers cells to the regenerative site and provides three-dimensional environments for the cells. To fulfil these functions, we design biodegradable polymer scaffolds with structural features on multiple size scales. To enhance positive cell-material interactions, we design nano-sized structural features in the scaffolds to mimic the natural extracellular matrix. We also integrate micro-sized pore networks to facilitate mass transport and neo tissue regeneration. We also design novel polymer devices and self-assembled nanospheres for biomolecule delivery to recapitulate key events in developmental and wound healing processes. Herein, we present recent work in biomedical polymer synthesis, novel processing techniques, surface engineering and biologic delivery. Examples of enhanced cellular/tissue function and regenerative outcomes of these approaches are discussed to demonstrate the excitement of the biomimetic scaffold design and biologic delivery in regenerative medicine. (topical review)

  3. Newcomer information seeking

    DEFF Research Database (Denmark)

    Moring, Camilla Elisabeth

    2016-01-01

    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...

  4. 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.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    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......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...

  6. 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.

  7. An integrated platform for biomolecule interaction analysis

    Science.gov (United States)

    Jan, Chia-Ming; Tsai, Pei-I.; Chou, Shin-Ting; Lee, Shu-Sheng; Lee, Chih-Kung

    2013-02-01

    We developed a new metrology platform which can detect real-time changes in both a phase-interrogation mode and intensity mode of a SPR (surface plasmon resonance). We integrated a SPR and ellipsometer to a biosensor chip platform to create a new biomolecular interaction measurement mechanism. We adopted a conductive ITO (indium-tinoxide) film to the bio-sensor platform chip to expand the dynamic range and improve measurement accuracy. The thickness of the conductive film and the suitable voltage constants were found to enhance performance. A circularly polarized ellipsometry configuration was incorporated into the newly developed platform to measure the label-free interactions of recombinant human C-reactive protein (CRP) with immobilized biomolecule target monoclonal human CRP antibody at various concentrations. CRP was chosen as it is a cardiovascular risk biomarker and is an acute phase reactant as well as a specific prognostic indicator for inflammation. We found that the sensitivity of a phaseinterrogation SPR is predominantly dependent on the optimization of the sample incidence angle. The effect of the ITO layer effective index under DC and AC effects as well as an optimal modulation were experimentally performed and discussed. Our experimental results showed that the modulated dynamic range for phase detection was 10E-2 RIU based on a current effect and 10E-4 RIU based on a potential effect of which a 0.55 (°/RIU) measurement was found by angular-interrogation. The performance of our newly developed metrology platform was characterized to have a higher sensitivity and less dynamic range when compared to a traditional full-field measurement system.

  8. 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.

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

    DEFF Research Database (Denmark)

    Aneheim, Emma; Albertsson, Per; Bäck, Tom;

    2015-01-01

    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...... 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...... vector, which can guide the radiation to the cancer cells. Consequently, an appropriate method is required for coupling the nuclide to the vector. To increase the availability of astatine-211 radiopharmaceuticals for targeted alpha therapy, their production should be automated. Here, we present a method...

  10. 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; Setrajčić, 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

  11. 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.

  12. 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.

  13. 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. PMID:27450905

  14. 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.

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

    International Nuclear Information System (INIS)

    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

  16. 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.

  17. 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

  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.

    2016-06-01

    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.

  19. 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...

  20. 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.

  1. Solvation dynamics of biomolecules: modeling and terahertz experiments.

    Science.gov (United States)

    Leitner, David M; Gruebele, Martin; Havenith, Martina

    2008-12-01

    The role of water in biomolecule dynamics has attracted much interest over the past decade, due in part to new probes of biomolecule-water interactions and developments in molecular simulations. Terahertz (THz) spectroscopy, among the most recent experimental methods brought to bear on this problem, is able to detect even small solute induced changes of the collective water network dynamics at the biomolecule-water interface. THz measurements reveal that proteins influence up to 1000 water molecules in their surroundings, and that even small saccharides influence the dynamics of hundreds of surrounding water molecules. The THz spectrum of a protein is sensitive to mutation and depends on the surface charge and flexibility of the protein. Influence on the solvation shell appears most pronounced for native wildtype proteins and decreases upon partial unfolding or mutation. THz spectra of solvated saccharides reveal that the number of water molecules coupled dynamically to a saccharide, forming a dynamical hydration shell around it, is related to the number of exposed oxygen atoms on the solute. The thickness of this layer appears correlated with the bioprotection efficiency of the saccharide. All findings support the thesis of a long-range dynamic coupling between biomolecule and solvent. PMID:19436490

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

    Science.gov (United States)

    Baiano, Antonietta

    2014-01-01

    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. PMID:25232705

  3. 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

  4. 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

  5. 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

  6. Detection of prostate-specific antigen with biomolecule-gated AlGaN/GaN high electron mobility transistors

    International Nuclear Information System (INIS)

    In order to improve the sensitivity of AlGaN/GaN high electron mobility transistor (HEMT) biosensors, a simple biomolecule-gated AlGaN/GaN HEMT structure was designed and successfully fabricated for prostate specific antigen (PSA) detection. UV/ozone was used to oxidize the GaN surface and then a 3-aminopropyl trimethoxysilane (APTES) self-assembled monolayer was bound to the sensing region. This monolayer serves as a binding layer for attachment of the prostate specific antibody (anti-PSA). The biomolecule-gated AlGaN/GaN HEMT sensor shows a rapid and sensitive response when the target prostate-specific antigen in buffer solution was added to the antibody-immobilized sensing area. The current change showed a logarithm relationship against the PSA concentration from 0.1 pg/ml to 0.993 ng/ml. The sensitivity of 0.215% is determined for 0.1 pg/ml PSA solution. The above experimental result of the biomolecule-gated AlGaN/GaN HEMT biosensor suggested that this biosensor might be a useful tool for prostate cancer screening. (paper)

  7. 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.

  8. Antifouling self-assembled monolayers on microelectrodes for patterning biomolecules.

    Science.gov (United States)

    Noel, John; Teizer, Winfried; Hwang, Wonmuk

    2009-01-01

    We present a procedure for forming a poly(ethylene glycol) (PEG) trimethoxysilane self-assembled monolayer (SAM) on a silicon substrate with gold microelectrodes. The PEG-SAM is formed in a single assembly step and prevents biofouling on silicon and gold surfaces. The SAM is used to coat microelectrodes patterned with standard, positive-tone lithography. Using the microtubule as an example, we apply a DC voltage to induce electrophoretic migration to the SAM-coated electrode in a reversible manner. A flow chamber is used for imaging the electrophoretic migration and microtubule patterning in situ using epifluorescence microscopy. This method is generally applicable to biomolecule patterning, as it employs electrophoresis to immobilize target molecules and thus does not require specific molecular interactions. Further, it avoids problems encountered when attempting to pattern the SAM molecules directly using lithographic techniques. The compatibility with electron beam lithography allows this method to be used to pattern biomolecules at the nanoscale. PMID:19707178

  9. 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).

  10. Models for Energy and Charge Transport, and Storage in Biomolecules

    CERN Document Server

    Mingaleev, S F; Gaididei, Yu B; Johansson, M; Rasmussen, K O; Mingaleev, Serge F.; Christiansen, Peter L.; Gaididei, Yuri B.; Johansson, Magnus; Rasmussen, Kim O.

    1999-01-01

    Two models for energy and charge transport and storage in biomolecules are considered. A model based on the discrete nonlinear Schrodinger equation with long-range dispersive interactions (LRI's) between base pairs of DNA is offered for the description of nonlinear dynamics of the DNA molecule. We show that LRI's are responsible for the existence of an interval of bistability where two stable stationary states, a narrow, pinned state and a broad, mobile state, coexist at each value of the total energy. The possibility of controlled switching between pinned and mobile states is demonstrated. The mechanism could be important for controlling energy storage and transport in DNA molecules. Another model is offered for the description of nonlinear excitations in proteins and other anharmonic biomolecules. We show that in the highly anharmonic systems a bound state of Davydov and Boussinesq solitons can exist.

  11. Immobilization of different biomolecules by atomic force microscopy

    Directory of Open Access Journals (Sweden)

    Hölzel Ralph

    2010-05-01

    Full Text Available Abstract Background Micrometer resolution placement and immobilization of probe molecules is an important step in the preparation of biochips and a wide range of lab-on-chip systems. Most known methods for such a deposition of several different substances are costly and only suitable for a limited number of probes. In this article we present a flexible procedure for simultaneous spatially controlled immobilization of functional biomolecules by molecular ink lithography. Results For the bottom-up fabrication of surface bound nanostructures a universal method is presented that allows the immobilization of different types of biomolecules with micrometer resolution. A supporting surface is biotinylated and streptavidin molecules are deposited with an AFM (atomic force microscope tip at distinct positions. Subsequent incubation with a biotinylated molecule species leads to binding only at these positions. After washing streptavidin is deposited a second time with the same AFM tip and then a second biotinylated molecule species is coupled by incubation. This procedure can be repeated several times. Here we show how to immobilize different types of biomolecules in an arbitrary arrangement whereas most common methods can deposit only one type of molecules. The presented method works on transparent as well as on opaque substrates. The spatial resolution is better than 400 nm and is limited only by the AFM's positional accuracy after repeated z-cycles since all steps are performed in situ without moving the supporting surface. The principle is demonstrated by hybridization to different immobilized DNA oligomers and was validated by fluorescence microscopy. Conclusions The immobilization of different types of biomolecules in high-density microarrays is a challenging task for biotechnology. The method presented here not only allows for the deposition of DNA at submicrometer resolution but also for proteins and other molecules of biological relevance that

  12. Spatially Controlled Covalent Immobilization of Biomolecules on Silicon Surfaces

    OpenAIRE

    Pavlovic, Elisabeth

    2003-01-01

    The work described in this thesis aims to achieving surface patterning through chemical activation of thiolated silicon oxide surfaces, resulting in a spatially controlled covalent immobilization of biomolecules with high resolution. Existing chemical methods to immobilize molecules on surfaces do not reach below the micrometer scale while the ones allowing for spatial control mostly lead to non-covalent adsorption of molecules on surfaces, or require several successive chemical reactions to ...

  13. GroPBS: Fast Solver for Implicit Electrostatics of Biomolecules

    OpenAIRE

    Bertelshofer, Franziska; Sun, Liping; Greiner, Günther; Böckmann, Rainer A.

    2015-01-01

    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 also guide the design of molecules with specified properties. However, explicit water models come at a high computational cost, rendering them unsuitable...

  14. Capillary Electrophoresis-based Methodology Development for Biomolecule Analysis

    OpenAIRE

    Li, Ni

    2011-01-01

    Capillary electrophoresis (CE) is a separation tool with wide applications in biomolecule analysis. Fast and high-resolution separation requiring minute sample volumes is advantageous to study multiple components in biological samples. Flexible modes and methods can be developed. In this thesis, I focus on developing and applying novel CE methods to study multi-target nucleic acid sensing with high sensitivity (Part I) and interactions between multiple components, i.e. proteins, nanoparticles...

  15. Mapping the Chemical Universe of Biomolecules for Astrobiology

    OpenAIRE

    Meringer, Markus

    2015-01-01

    Understanding the origins of life is a central question of Astrobiology. Computer methods offer unique means to approach this challenge. In order to obtain a better understanding of the selection rules which guided chemical and early biochemical evolution, our approach is to computationally generate exhaustive sets of biomolecule analogues, to calculate their physico-chemical properties, and to simulate adaptive processes that might have led to the biochemical foundations of life as we know i...

  16. The first search for glycine and other biomolecules

    OpenAIRE

    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 astrobio...

  17. 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

  18. Models for Energy and Charge Transport and Storage in Biomolecules

    OpenAIRE

    Mingaleev, S. F.; Christiansen, P. L.; Gaididei, Yu. B.; M. Johansson; Rasmussen, K.Ø.

    1999-01-01

    Two models for energy and charge transport and storage in biomolecules are considered. A model based on the discrete nonlinear Schrodinger equation with long-range dispersive interactions (LRI's) between base pairs of DNA is offered for the description of nonlinear dynamics of the DNA molecule. We show that LRI's are responsible for the existence of an interval of bistability where two stable stationary states, a narrow, pinned state and a broad, mobile state, coexist at each value of the tot...

  19. Applications of polymers for biomolecule immobilization in electrochemical biosensors

    International Nuclear Information System (INIS)

    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

  20. Biomolecule-assisted route to prepare titania mesoporous hollow structures.

    Science.gov (United States)

    Ding, Shangjun; Wang, Yaoming; Hong, Zhanglian; Lü, Xujie; Wan, Dongyun; Huang, Fuqiang

    2011-10-01

    Amino acids, as a particularly important type of biomolecules, have been used as multifunctional templates to intelligently construct mesoporous TiO(2) hollow structures through a simple solvothermal reaction. The structure-directing behaviors of various amino acids were systematically investigated, and it was found that these biomolecules possess the general capability to assist mesoporous TiO(2) hollow-sphere formation. At the same time, the nanostructures of the obtained TiO(2) are highly dependent on the isoelectric points (pI) of amino acids. Their molecular-structure variations can lead to pI differences and significantly influence the final TiO(2) morphologies. Higher-pI amino acids (e.g., L-lysine and L-arginine) have better structure-directing abilities to generate nanosheet-assembled hollow spheres and yolk/shell structures. The specific morphologies and mesopore size of these novel hollow structures can also be tuned by adjusting the titanium precursor concentration. Heat treatment in air and vacuum was further conducted to transform the as-prepared structures to porous nanoparticle-assembled hollow TiO(2) and TiO(2)/carbon nanocomposites, which may be potentially applied in the fields of photocatalysts, dye-sensitized solar cells, and Li batteries. This study provides some enlightenment on the design of novel templates by taking advantage of biomolecules. PMID:21882272

  1. 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.

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

    International Nuclear Information System (INIS)

    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

  3. Breakdowns in collaborative information seeking

    DEFF Research Database (Denmark)

    Hertzum, Morten

    2010-01-01

    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...... 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...

  4. Variety Seeking Through Brand Switching

    OpenAIRE

    Moshe Givon

    1984-01-01

    A concept of variety seeking behavior is modeled as a stochastic brand choice model. The model yields a measure of variety seeking for each individual consumer. Panel data for 28 products are analyzed for each household and the possibility of market segmentation by variety seeking behavior is explored.

  5. Rent Seeking: A Textbook Example

    Science.gov (United States)

    Pecorino, Paul

    2007-01-01

    The author argues that the college textbook market provides a clear example of monopoly seeking as described by Tullock (1967, 1980). This behavior is also known as rent seeking. Because this market is important to students, this example of rent seeking will be of particular interest to them. (Contains 24 notes.)

  6. 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....... 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...... 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...

  7. 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. PMID:24815719

  8. 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.

  9. 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

  10. 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

  11. Chemical tags for site-specific fluorescent labeling of biomolecules.

    Science.gov (United States)

    Freidel, Christoph; Kaloyanova, Stefka; Peneva, Kalina

    2016-06-01

    This review focuses on the various approaches to covalently attach a chromophore to a biomolecule of interest in site-specific manner. Novel methods like inverse electron-demand Diels-Alder reaction, Pictet-Spengler ligation and enzyme tags like SNAP and Halo-tags are critically discussed and compared to established techniques like copper-free click reaction and native chemical ligation. Selected examples in which the tags have been exploited for in vitro or in vivo imaging are reviewed and evaluated. PMID:26969255

  12. SENSATION SEEKING SCALE: INDIAN ADAPTATION

    OpenAIRE

    Basu, Debasish; Verma, Vijoy K.; Malhotra, Savita; Malhotra, Anil

    1993-01-01

    SUMMARY Sensation seeking refers to a biologically based personality dimension defined as the need for varied, novel and complex sensations and experiences, and the willingness to take physical and social risks for the sake of such experiences. Although researched worldwide for nearly three decades now, there is to date no published Indian study utilizing the concept of sensation seeking. This paper describes adaptation of the Sensation Seeking Scale for the Indian population. After due modif...

  13. 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.

  14. Immobilization of Biomolecules on Poly(vinyldimethylazlactone)-containing Surface Scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Barrninger, Joshua [Clemson University; Messman, Jamie M [ORNL; Banaszak, Abigail [Clemson University; Meyer III, Harry M [ORNL; Kilbey, II, S Michael [ORNL

    2009-01-01

    We describe the successful development of a procedure for the step-by-step formation of a reactive, multi-layer polymer scaffold incorporating polymers based on 2-vinyl-4,4-dimethylazlactone (VDMA) on a silicon wafer and the characterization of these materials. Also discussed is the development of a procedure for the non-site specific attachment of a biomolecule to the modified silicon wafer, including scaffolds modified via drop-on-demand (DOD) inkjet printing. VDMA-based polymers were used because of their hydrolytic stability and ability of the pendant azlactone rings to form stable covalent bonds with primary amines without byproducts via nucleophilic addition. This reaction proceeds without a catalyst and at room temperature, yielding a stable amide linkage, which adds to the ease of construction expected when using VDMA-based polymers. DOD inkjet printing was explored as an interesting method for creating surfaces with one or more patterns of biomolecules, because of the flexibility and ease in pattern design.

  15. 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.

  16. 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

    2016-01-01

    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. PMID:26999123

  17. On biomolecules and semiconductors: Analytical studies of interface dynamics

    Science.gov (United States)

    Slavin, John William Joseph

    The studies discussed here were undertaken to examine the use of III-V semiconducting materials as templates for biomolecules, to be applied in such technologies as Field-Effect Transistor (FET) and Light-emitting Diode (LED) biosensors. Materials application requires an informed analysis of interactions between chemical environments. Specific to surfaces, this means investigating the molecular interactions between the substrate and the bonding moieties. The analytical tools used to probe these interactions, and the changes that such communication causes on specific substrates are specifically discussed. Surface analysis tools included in this review are Atomic Force Microscopy (AFM), Nanoindentation, X-ray Photoelectron Spectroscopy (XPS), and Raman Microscopy. The interaction of biomolecules - deoxyribonucleic acid (DNA), proteins adhered to nanoparticles, and amino acids - on semiconductor surfaces is also examined. Proper investigation follows, as well, the methods of applying these biomolecular structures to the specified surfaces, through procedures such as solution phase transfer, as well as Dip-pen Nanolithography (DPN). The stretching and enzymatic cleavage of DNA, on silicon oxide surfaces, was studied to determine the recognition properties of dual-enzymatic systems on surfaces. Fundamental questions such as the interaction of functional groups with InAs(100) surfaces, the mechanical properties of protein modified systems, and the DPN application of biologically relevant linker molecules to InAs(100) surfaces were explored. These studies provide information applicable to the development of novel sensing platforms in the future.

  18. Physical Mechanisms of Crystal Growth Modification by Biomolecules

    Science.gov (United States)

    De Yoreo, James J.

    2010-07-01

    During the process of biomineralization, living organisms use macromolecules to direct the nucleation and growth of a variety of inorganic materials. Because biomineral structures exhibit complex topologies, hierarchical design, and unique materials properties, an understanding of the underlying mechanisms of biomolecular controls over mineral growth presents an opportunity to develop new strategies towards synthesis of novel materials for applications across a wide range of technologies. Herein the results from a combination of in situ atomic force microscopy (AFM) and molecular modeling (MM) studies to investigate the effect of specific interactions between carboxylate-rich biomolecules and atomic steps on calcium carbonate and calcium oxalate crystal surfaces during the growth are reviewed. The results show how the stereochemical relationships between additive and atomic step leads to modifications of crystal shape. In some cases, the inhibitory effects of strong binders are well-explained by a model of growth inhibition based on the classic Cabrera-Vermilyea theory, but updated to take into account the particular nature of biomolecular adsorption dynamics. The consequences include a positive feedback between peptide adsorption and step inhibition that results in bistable growth with rapid switching from fast to near-zero growth rates for very small changes in supersaturation. The phenomenon of biomolecule-induced growth acceleration is also reviewed and shown to be common to both the oxalate and carbonate systems. The source of acceleration is related to the activation barrier for solute attachment to steps. Finally, experimental and theoretical results are presented that suggest most biomineral phases can not be described by conventional models in which kink formation due to thermal fluctuations at step edges is rapid enough to ensure the availability of kinks. Instead, growth is kink-limited. As a consequence, biomolecule-step interactions cannot be

  19. 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

  20. 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

  1. 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

  2. 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.

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

    Science.gov (United States)

    Cardellini, Annalisa; Fasano, Matteo; Chiavazzo, Eliodoro; Asinari, Pietro

    2016-04-01

    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.

  4. Interactions of model biomolecules. Benchmark CC calculations within MOLCAS

    Energy Technology Data Exchange (ETDEWEB)

    Urban, Miroslav [Slovak University of Technology in Bratislava, Faculty of Materials Science and Technology in Trnava, Institute of Materials Science, Bottova 25, SK-917 24 Trnava, Slovakia and Department of Physical and Theoretical Chemistry, Faculty of Natural Scie (Slovakia); Pitoňák, Michal; Neogrády, Pavel; Dedíková, Pavlína [Department of Physical and Theoretical Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina, SK-842 15 Bratislava (Slovakia); Hobza, Pavel [Institute of Organic Chemistry and Biochemistry and Center for Complex Molecular Systems and biomolecules, Academy of Sciences of the Czech Republic, Prague (Czech Republic)

    2015-01-22

    We present results using the OVOS approach (Optimized Virtual Orbitals Space) aimed at enhancing the effectiveness of the Coupled Cluster calculations. This approach allows to reduce the total computer time required for large-scale CCSD(T) calculations about ten times when the original full virtual space is reduced to about 50% of its original size without affecting the accuracy. The method is implemented in the MOLCAS computer program. When combined with the Cholesky decomposition of the two-electron integrals and suitable parallelization it allows calculations which were formerly prohibitively too demanding. We focused ourselves to accurate calculations of the hydrogen bonded and the stacking interactions of the model biomolecules. Interaction energies of the formaldehyde, formamide, benzene, and uracil dimers and the three-body contributions in the cytosine – guanine tetramer are presented. Other applications, as the electron affinity of the uracil affected by solvation are also shortly mentioned.

  5. Vacuum foam drying: An alternative to lyophilization for biomolecule preservation

    Directory of Open Access Journals (Sweden)

    R D Jangle

    2012-01-01

    Full Text Available Vacuum foam drying is evaluated as an alternative for lyophilization for enhanced process and storage stability of bovine serum albumin. The protein protective efficiency of different stabilizers was compared in vacuum foam drying and lyophilization. Sucrose mixtures produced better foam characters than mannitol. Unlike calcium lactate, incorporation of polyvinyl pyrrolidone to sucrose synergistically enhanced the recovery of bovine serum albumin. The conformational stability and bovine serum albumin content further increased with sodium phosphate as compared to potassium phosphate. All sucrose mixtures, except calcium lactate showed large α-helix amide-I band at approximately 1656 cm -1 . The amorphous powder diffraction in case of sodium phosphate monobasic mixture retained maximum bovine serum albumin content. The crystallization of similar mixtures in lyophilization reduced its bovine serum albumin content. Vacuum foam drying showed better processing and storage stability of bovine serum albumin than lyophilization process. Hence vacuum foam drying is short, simple and industrially economical process for biomolecules preservation.

  6. 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.

  7. 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

  8. 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.

  9. Platinum(II) complexes as spectroscopic probes for biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Ratilla, E.

    1990-09-21

    The use of platinum(II) complexes as tags and probes for biomolecules is indeed advantageous for their reactivities can be selective for certain purposes through an interplay of mild reaction conditions and of the ligands bound to the platinum. The use of {sup 195}Pt NMR as a method of detecting platinum and its interactions with biomolecules was carried out with the simplest model of platinum(II) tagging to proteins. Variable-temperature {sup 195}Pt NMR spectroscopy proved useful in studying the stereodynamics of complex thioethers like methionine. The complex, Pt(trpy)Cl{sup +}, with its chromophore has a greater potential for probing proteins. It is a noninvasive and selective tag for histidine and cysteine residues on the surface of cytochrome c at pH 5. The protein derivatives obtained are separable, and the tags are easily quantitated and differentiated through the metal-to-ligand charge transfer bands which are sensitive to the environment of the tag. Increasing the pH to 7.0 led to the modification by Pt(trpy)Cl{sup +}of Arg 91 in cytochrome c. Further studies with guanidine-containing ligands as models for arginine modification by Pt(trpy)Cl{sup +} showed that guanidine can act as a terminal ligand and as a bridging ligand. Owing to the potential utility of Pt(trpy)L{sup n+} as electron dense probes of nucleic acid structure, interactions of this bis-Pt(trpy){sup 2+} complex with nucleic acids was evaluated. Indeed, the complex interacts non-covalently with nucleic acids. Its interactions with DNA are not exactly the same as those of its precedents. Most striking is its ability to form highly immobile bands of DNA upon gel electrophoresis. 232 refs.

  10. Today's Physicians Seek Career Direction.

    Science.gov (United States)

    Morgan-Haker, Veronica R.

    1998-01-01

    Changes in the role of the physician in today's society have made their career choices risky. Career specialists have an opportunity to assist those who do not normally seek career advice outside their own profession. (JOW)

  11. Wavelength Selection For Laser Raman Spectroscopy of Putative Martian Habitats and Biomolecules

    Science.gov (United States)

    Wynn-Williams, D. D.; Newton, E. M. G.; Edwards, H. G. M.

    Pigments are key potential biomarkers for any former life on Mars because of the selective pressure of solar radiation on any biological system that could have evolved at its surface. We have found that the near -Infrared laser Raman spectrometer available to use was eminently suitable for diagnostic analysis of pigments because of their minimal autofluorescence at its 1064 nm excitation wav elength. However, we have now evaluated a diverse range of excitation wavelengths to confirm this choice, to ensure that we have the best technique to seek for pigments and their derivatives from any former surface life on Mars. The Raman is weak relative to fluorescence, which results in elevated baseline and concurrent swamping of Raman bands. We confirm the molecular information available from near-IR FT Raman spectra for two highly pigmented UV-tolerant epilithic Antarctic lichens (Acarospora chlorop hana and Caloplaca saxicola) from Victoria Land, a whole endolithic microbial community and endolithic cyanobacterium Chroococcidiopsis from within translucent sandstone of the Trans -Antarctic Mountains, and the free- living cyanobacterium Nostoc commune from Alexander Island, Antarctic Peninsula region. We also show that much of the information we require on biomolecules is not evident from lasers of shorter wavelengths. A miniature 1064 nm Raman spectrometer with an In-Ga-As detector sensitive to IR is being developed by Montana State University (now existing as a prototype) as the prime instrument for a proposed UK-led Mars rover mission (Vanguard). Preliminary spectra from this system confirm the suitability of the near-IR laser.

  12. 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).

  13. 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

  14. 123I and 13I purification for biomolecules labelling

    International Nuclear Information System (INIS)

    The 123I and 131I are iodine radioisotopes widely used in Nuclear Medicine. The radioisotope 123I is used in diagnosis through the SPECT technique and is routinely produced at IPEN in cyclotron through the reaction: '124Xe (p, 2n) '123Cs -> 123Xe -> 123I. The radioisotope 131I is used both in diagnosis and therapy due to its physical characteristics of decay by β- and its γ-ray emissions that are softened with the use of specific collimators for diagnosis. It is routinely produced at IPEN using the nuclear reactor through the indirect reaction: 130Te (n, γ) ->131Te -> 131I, irradiating compounds containing Te. The radiopharmaceuticals prepared with these radioisotopes go through rigorous quality control tests and the chemical purity of the primary radioisotopes 123I and 131I are within the permissible limits currently defined. However, the presence of some chemical contaminants can prejudice the biomolecules labeling (monoclonal antibodies and peptides), that will produce radiopharmaceuticals of first generation to the oncology area. The aim of this work was to obtain a new purification method of these radioisotopes, allowing the labeling of biomolecules and also to established a process control on those radioisotopes. The methodology was separated on 3 steps: Evaluation of '123I e 131I radionuclidic purity using a hyper pure germanium detector, chemical purity using ICP-OES and the retention and elution study of 131I in several absorbers to choose the most appropriate for the purification tests analyzing the behavior of the possible contaminants. The radionuclidic analyses showed the presence of Te and Co on 131I samples and Te, Tc e Co on 123I samples. The chemical purity analyses showed the presence of Al and Mo in 123I, coming from the window material of the target holder and the presence of Al and Te in 131I samples, coming from the target holder and the target, respectively. The retention and elution study selected the most promising adsorber to the

  15. 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

  16. 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.

  17. 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

  18. 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 s......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...... 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...

  19. 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.

  20. Diagnostic and therapeutic perspectives in nuclear medicine: radiolabelled biomolecules

    International Nuclear Information System (INIS)

    From their beginning, the radiopharmaceuticals chemistry has gone to the study of the molecular chemistry. The radiopharmaceuticals are only in their capacity to detect such specific biochemical places as the receivers and the enzymes. With the recent obtaining of the complete structural sequence of the genome, it doesn't fit doubt of the importance that they have acquired the molecular images for the study from the genetic information to the alterations phenotypic in the chemistry of the human body. So, the future of the diagnostic and therapeutic nuclear medicine, practically is based in the study of protein fragments, peptide structures and chains of DNA radiolabelled for the study of the metabolism In vivo. These investigations represent a substantial change in those paradigms of the pharmaceutical development, when using the own organic capacities as source of medications, instead of considering to the organism like a simple assay tube where molecules act, like they are most of the traditional medications. The investigation of new techniques to design complex stable of Tc-99m, Re-188, Lu-177, Y-90 and Dy-166/Ho-l66 with biomolecules that don't alter the specificity and in general the molecular properties of the same ones. it is a topic of world interest in the environment of the radiopharmaceutical chemistry. In this work some achievements and perspectives are presented on those main diagnostic and therapeutic radiopharmaceuticals of third generation. (Author)

  1. 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.

  2. 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.

  3. 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.

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

    International Nuclear Information System (INIS)

    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.

  5. 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. PMID:26579616

  6. 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.

  7. Synthesis of vaterite and aragonite crystals using biomolecules of tomato and capsicum

    Science.gov (United States)

    Chen, Long; Xu, Wang-Hua; Zhao, Ying-Guo; Kang, Yan; Liu, Shao-Hua; Zhang, Zai-Yong

    2012-12-01

    In this paper, biomimetic synthesis of calcium carbonate (CaCO3) in the presence of biomolecules of two vegetables-tomato and capsicum is investigated. Scanning electron microscopy and X-ray powder diffractometry were used to characterize the CaCO3 obtained. The biomolecules in the extracts of two vegetables are determined by UV-vis or FTIR. The results indicate that a mixture of calcite and vaterite spheres constructed from small particles is produced with the extract of tomato, while aragonite rods or ellipsoids are formed in the presence of extract of capsicum. The possible formation mechanism of the CaCO3 crystals with tomato biomolecules can be interpreted by particle-aggregation based non-classical crystallization laws. The proteins and/or other biomolecules in tomato and capsicum may control the formation of vaterite and aragonite crystals by adsorbing onto facets of them.

  8. 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.

  9. 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. PMID:27312484

  10. 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.

  11. Stage 2--Information Seeking Strategies

    Science.gov (United States)

    Elsenberg, Michael B.

    2005-01-01

    A brief overview of one Big6 stage by Mike Eisenberg, followed by articles by two exemplary Big6 teachers, Barbara Jansen and Rob Darrow, offering practical uses of the Big6 in elementary and secondary situations is presented. The two-part nature of information seeking strategies that includes brainstorming and choosing is emphasized.

  12. Teachers Seek Specialized Peer Networks

    Science.gov (United States)

    Tomassini, Jason

    2013-01-01

    Within the wide expanse of social networking, educators appear to be gravitating to more protected and exclusive spaces. While teachers often use such popular mainstream social networks as Facebook, they are more likely to seek out and return to less-established networks that offer the privacy, peer-to-peer connections, and resource sharing that…

  13. Strategic Asset Seeking by EMNEs

    DEFF Research Database (Denmark)

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

    2014-01-01

    Purpose: The chapter provides an economic explanation and perspectivation of strategic asset seeking of multinational enterprises from emerging economies (EMNEs) as a prominent feature of today’s global economy. Approach: The authors apply and extend the “springboard perspective.” This perspectiv...

  14. 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.

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

    International Nuclear Information System (INIS)

    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

  16. 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.

  17. Information Seeking From Media and Family/Friends Increases the Likelihood of Engaging in Healthy Lifestyle Behaviors

    OpenAIRE

    RAMÍREZ, A. SUSANA; Freres, Derek; MARTINEZ, LOURDES S.; LEWIS, NEHAMA; BOURGOIN, ANGEL; Kelly, Bridget J.; Lee, Chul-joo

    2013-01-01

    The amount of cancer-related information available to the general population continues to grow, yet its effects are unclear. This study extends previous cross-sectional research establishing that cancer information seeking across a variety of sources is extensive and positively associated with engaging in health-related behaviors. We studied how active information seeking about cancer prevention influenced three healthy lifestyle behaviors using a two-round nationally representative sample of...

  18. Effect of membrane hydrophilization on ultrafiltration performance for biomolecules separation

    Energy Technology Data Exchange (ETDEWEB)

    Susanto, H., E-mail: heru.susanto@undip.ac.id [Department of Chemical Engineering, Universitas Diponegoro, Jl. Prof. Sudarto-Tembalang, Semarang (Indonesia); Roihatin, A.; Aryanti, N.; Anggoro, D.D. [Department of Chemical Engineering, Universitas Diponegoro, Jl. Prof. Sudarto-Tembalang, Semarang (Indonesia); Ulbricht, M. [Lehrstuhl fuer Technische Chemie, Universitaet Duisburg-Essen, Germany, Universitaetstr. 5, Essen (Germany)

    2012-10-01

    fouling ultrafiltration (UF) membranes. Black-Right-Pointing-Pointer We characterized the membranes before and after modification. Black-Right-Pointing-Pointer We examined the unmodified and modified membranes for biomolecules filtration. Black-Right-Pointing-Pointer All the modifications changed the membrane characteristics and the membrane performance. Black-Right-Pointing-Pointer All the modifications resulted in UF membranes having higher resistance towards fouling.

  19. Effect of membrane hydrophilization on ultrafiltration performance for biomolecules separation

    International Nuclear Information System (INIS)

    characterized the membranes before and after modification. ► We examined the unmodified and modified membranes for biomolecules filtration. ► All the modifications changed the membrane characteristics and the membrane performance. ► All the modifications resulted in UF membranes having higher resistance towards fouling.

  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. Cancer

    Science.gov (United States)

    ... Blood tests (which look for chemicals such as tumor markers) Bone marrow biopsy (for lymphoma or leukemia) Chest ... the case with skin cancers , as well as cancers of the lung, breast, and colon. If the tumor has spread ...

  2. 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 ...

  3. Celebrity disclosures and information seeking: The case of Angelina Jolie

    OpenAIRE

    Juthe, Robin H.; Zaharchuk, Amber; Wang, Catharine

    2014-01-01

    Purpose On May 14, 2013, actress Angelina Jolie disclosed that she had a BRCA1 mutation and underwent a prophylactic bilateral mastectomy. This study documents the impact of her disclosure on information-seeking behavior, specifically regarding online genetics and risk reduction resources available from the National Cancer Institute (NCI). Methods Using Adobe Analytics, daily page views for 11 resources were tracked from April 23, 2013 through June 25, 2013. Usage data were also obtained for ...

  4. Predicting job-seeking intensity and job-seeking intention in the sample of unemployed

    Directory of Open Access Journals (Sweden)

    Marić Zorica

    2005-01-01

    Full Text Available In this study Ajzen' theory (1991 of planned behavior was used to predict job - seek intention and behavior among unemployed people (N = 650. In addition to theory of planned behavior variables (job - seek attitude, subjective norm, self - efficacy and controllability of job seek process we used several other psychological (financial pressure, self - mastery, self - esteem and depression and demographic (gender, age, education, marriage and lent of unemployment variables to build a model of predictors for both criterion variables. Financial pressure, intention to seek employment, job seek - self - efficacy, job - seek controllability, marriage and job - seek attitude predicted job - seeking behavior, while attitude toward job - seeking, subjective norm, job - seek self - efficacy and financial pressure predicted job seek - intention. Results are discussed in light of theory of planned behavior, current research of job - seeking behavior and recommendations are made for practice.

  5. Cancer Therapy Evaluation Program | Office of Cancer Genomics

    Science.gov (United States)

    The Cancer Therapy Evaluation Program (CTEP) seeks to improve the lives of cancer patients by finding better treatments, control mechanisms, and cures for cancer. CTEP funds a national program of cancer research, sponsoring clinical trials to evaluate new anti-cancer agents.

  6. 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. PMID:26930392

  7. 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.)

  8. From biominerals to biomaterials: the role of biomolecule-mineral interactions.

    Science.gov (United States)

    Perry, Carole C; Patwardhan, Siddharth V; Deschaume, Olivier

    2009-08-01

    Interactions between inorganic materials and biomolecules at the molecular level, although complex, are commonplace. Examples include biominerals, which are, in most cases, facilitated by and in contact with biomolecules; implantable biomaterials; and food and drug handling. The effectiveness of these functional materials is dependent on the interfacial properties, i.e. the extent of molecular level 'association' with biomolecules. The present article gives information on biomolecule-inorganic material interactions and illustrates our current understanding using selected examples. The examples include (i) mechanism of biointegration: the role of surface chemistry and protein adsorption, (ii) towards improved aluminium-containing materials, and (iii) understanding the bioinorganic interface: experiment and modelling. A wide range of experimental techniques (microscopic, spectroscopic, particle sizing, thermal methods and solution methods) are used by the research group to study interactions between (bio)molecules and molecular and colloidal species that are coupled with computational simulation studies to gain as much information as possible on the molecular-scale interactions. Our goal is to uncover the mechanisms underpinning any interactions and to identify 'rules' or 'guiding principles' that could be used to explain and hence predict behaviour for a wide range of (bio)molecule-mineral systems. PMID:19614576

  9. Room temperature ionic liquids interacting with bio-molecules: an overview of experimental and computational studies

    Science.gov (United States)

    Benedetto, Antonio; Ballone, Pietro

    2016-03-01

    We briefly review experimental and computational studies of room temperature ionic liquids (RTILs) interacting with important classes of biomolecules, including phospholipids, peptides and proteins, nucleic acids and carbohydrates. Most of these studies have been driven by the interest for RTILs applications as solvents. Thus, available experimental data cover primarily thermodynamic properties such as the reciprocal solubility of RTILs and bio-molecules, as well as phase boundaries. Less extensive data are also available on transport properties such as diffusion and viscosity of homogeneous binary (RTILs/biomolecules) and ternary (RTIL/biomolecules/water) solutions. Most of the structural information at the atomistic level, of interest especially for biochemical, pharmaceutical and nanotechnology applications, has been made available by molecular dynamics simulations. Major exceptions to this statement are represented by the results from NMR and circular dichroism spectroscopy, by selected neutron and X-ray scattering data, and by recent neutron reflectometry measurements on lipid bilayers on surfaces, hydrated by water-RTIL solutions. A final section of our paper summarizes new developments in the field of RTILs based on amino acids, that combine in themselves the two main aspects of our discussion, i.e. ionic liquids and bio-molecules.

  10. An aptamer-functionalized chemomechanically modulated biomolecule catch-and-release system

    Science.gov (United States)

    Shastri, Ankita; McGregor, Lynn M.; Liu, Ya; Harris, Valerie; Nan, Hanqing; Mujica, Maritza; Vasquez, Yolanda; Bhattacharya, Amitabh; Ma, Yongting; Aizenberg, Michael; Kuksenok, Olga; Balazs, Anna C.; Aizenberg, Joanna; He, Ximin

    2015-05-01

    The efficient extraction of (bio)molecules from fluid mixtures is vital for applications ranging from target characterization in (bio)chemistry to environmental analysis and biomedical diagnostics. Inspired by biological processes that seamlessly synchronize the capture, transport and release of biomolecules, we designed a robust chemomechanical sorting system capable of the concerted catch and release of target biomolecules from a solution mixture. The hybrid system is composed of target-specific, reversible binding sites attached to microscopic fins embedded in a responsive hydrogel that moves the cargo between two chemically distinct environments. To demonstrate the utility of the system, we focus on the effective separation of thrombin by synchronizing the pH-dependent binding strength of a thrombin-specific aptamer with volume changes of the pH-responsive hydrogel in a biphasic microfluidic regime, and show a non-destructive separation that has a quantitative sorting efficiency, as well as the system's stability and amenability to multiple solution recycling.

  11. 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.

  12. 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 ...

  13. Help-Seeking Attitudes among Israeli Adolescents.

    Science.gov (United States)

    Tishby, Orya; Turel, Miriam; Gumpel, Omer; Pinus, Uri; Lavy, Shlomit Ben; Winokour, Miriam; Sznajderman, Semi

    2001-01-01

    Study investigated the willingness of Israeli adolescents to seek help for emotional and health problems, and their preference for various helping agents. Gender and age were identified as factors associated with help seeking attitudes. In general, adolescents preferred seeking help from family and peers, rather than professionals, for emotional…

  14. [Cancer].

    Science.gov (United States)

    de la Peña-López, Roberto; Remolina-Bonilla, Yuly Andrea

    2016-09-01

    Cancer is a group of diseases which represents a significant public health problem in Mexico and worldwide. In Mexico neoplasms are the second leading cause of death. An increased morbidity and mortality are expected in the next decades. Several preventable risk factors for cancer development have been identified, the most relevant including tobacco use, which accounts for 30% of the cancer cases; and obesity, associated to another 30%. These factors, in turn, are related to sedentarism, alcohol abuse and imbalanced diets. Some agents are well knokn to cause cancer such as ionizing radiation, viruses such as the papilloma virus (HPV) and hepatitis virus (B and C), and more recently environmental pollution exposure and red meat consumption have been pointed out as carcinogens by the International Agency for Research in Cancer (IARC). The scientific evidence currently available is insufficient to consider milk either as a risk factor or protective factor against different types of cancer. PMID:27603890

  15. Induction of Biomolecules in Mature Leaves of Terminalia arjuna Due to Feeding of Antheraea mylitta Drury

    Directory of Open Access Journals (Sweden)

    G. Abraham

    2004-01-01

    Full Text Available Terminalia arjuna is an important food plant of the tasar silkworm, Antheraea mylitta Drury. In this study, we investigated the induction of biomolecules in mature leaves of these plants subjected to insect feeding. Increase in total tannin content, lipid peroxidation, and trypsin inhibitor activity have been observed in mature leaves damaged by the insects. The growth rate of Vth instar larvae of A. mylitta fed on previously damaged foliage reduced by 87.1%. Induction of biomolecules for defense mechanisms in relation to herbivore damage has been discussed.

  16. A Model of Stochastic Variety-Seeking

    OpenAIRE

    Minakshi Trivedi; Frank M. Bass; Ram C. Rao

    1994-01-01

    In this paper, we propose and test a stochastic model of consumer choice that incorporates attribute-based variety seeking. Our stochastic variety-seeking model (SVS) has nested within it a fixed variety-seeking model, a zero-order model of choice, and a first-order (“pure variety”) model. We compare the SVS model to alternative models. Under stochastic variety seeking, we examine the nature of the variety sought and provide a test of the “satiation” hypothesis. Unlike fixed variety-seeking m...

  17. Bone-seeking radiopharmaceuticals in skeletal malignancy: evolution, not revolution

    International Nuclear Information System (INIS)

    Many advanced malignancies are complicated by skeletal metastases, with attendant pain and disability. External beam radiotherapy is still the most effective treatment for isolated lesions. Bone-seeking radiopharmaceuticals were perceived as a means of delivering radiation to multiple lesions simultaneously. A wide variety of radioisotopes have been used in this endeavor, with myelosuppression being the most significant potential adverse effect. Benefits of treatment are modest, including a transient improvement in pain control and perhaps prolongation of the treatment-free period. This is best demonstrated in prostate cancer with lower responses by skeletal metastases from breast and lung cancers. However, the treatment is yet to produce any improvement in patient survival. Experimental approaches to improve treatment efficacy include combination with cytotoxic therapy, and administration earlier in the course of the disease. Bone seeking radiopharmaceuticals have been used in treatment of advanced osteosarcoma in humans and canines and achieved effective palliation. The myelosuppressive effects of these agents have been exploited in patients with multiple myeloma to assist in attaining myeloablation prior to stem cell transplantation. Development of more potent non-radiolabelled bisphosphonates and recognition of their antitumour effect against several tumours has sparked a recrudescence of interest in their use for bone metastases. Set against these developments, the role of bone-seeking radiopharmaceuticals in skeletal metastases may need to be redefined

  18. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yan

    2011-05-15

    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

  20. 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. PMID:27558730

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

    Science.gov (United States)

    Tian, Ye; Wang, Wenhui; Wu, Nan; Zou, Xiaotian; Wang, Xingwei

    2011-01-01

    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. PMID:22163821

  2. Extraction of Biomolecules Using Phosphonium-Based Ionic Liquids + K3PO4 Aqueous Biphasic Systems

    Directory of Open Access Journals (Sweden)

    Cláudia L. S. Louros

    2010-04-01

    Full Text Available Aqueous biphasic systems (ABS provide an alternative and efficient approach for the extraction, recovery and purification of biomolecules through their partitioning between two liquid aqueous phases. In this work, the ability of hydrophilic phosphonium-based ionic liquids (ILs to form ABS with aqueous K3PO4 solutions was evaluated for the first time. Ternary phase diagrams, and respective tie-lines and tie-lines length, formed by distinct phosphonium-based ILs, water, and K3PO4 at 298 K, were measured and are reported. The studied phosphonium-based ILs have shown to be more effective in promoting ABS compared to the imidazolium-based counterparts with similar anions. Moreover, the extractive capability of such systems was assessed for distinct biomolecules (including amino acids, food colourants and alkaloids. Densities and viscosities of both aqueous phases, at the mass fraction compositions used for the biomolecules extraction, were also determined. The evaluated IL-based ABS have been shown to be prospective extraction media, particularly for hydrophobic biomolecules, with several advantages over conventional polymer-inorganic salt ABS.

  3. 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.

  4. 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.

  5. 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...

  6. 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...

  7. 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...

  8. 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. PMID:27560177

  9. Pdvsa, seeks foreign investment hike

    International Nuclear Information System (INIS)

    Looking at a protracted cash crunch, state oil company Petroleos de Venezuela SA plans to encourage accelerated investment by foreign companies in Venezuela's oil sector. Pdvsa late last month sliced about $1 billion from its capital and operating budget for 1992. This paper reports that in the medium term, Pdvsa plans to focus on investment in quicker payout projects in oil production and refining while seeking foreign capital for as many projects as possible in oil and gas exploration and development, petrochemicals, and coal. And it will continue to expand its presence in other countries, especially the US, to maintain market shares of crude and refined products exports. Those are among the business strategies outlined by new Pdvsa Pres. Gustavo Roosen after his first 100 days on the job. Pdvsa sees a key window of opportunity in gaining part of the market share lost by US crude producers as their production continues to decline. Pdvsa production outlays this decade are estimated at $4.4 billion. Pdvsa continues to hold to its target of crude productive capacity at 3.3 million b/d by 1996. The company wants to jump capacity as quickly as prudently possible from the yearend 1991 level of 2.83 million b/d. Currently, Pdvsa must buy 6000,000 b/d of oil on the US market to meet all of its commitments

  10. 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. ...

  11. 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 ...

  12. Effect of biomolecules adsorption on oxide layers developed on metallic materials used in cooling water systems

    International Nuclear Information System (INIS)

    This thesis was carried out in the frame of the BIOCOR ITN European project, in collaboration with the industrial partner RSE S.p.A. (Italy). Metallic materials commonly used in cooling systems of power plants may be affected by bio-corrosion induced by biofilm formation. The objective of this work was to study the influence of biomolecules adsorption, which is the initial stage of biofilm formation, on the electrochemical behaviour and the surface chemical composition of three metallic materials (70Cu-30Ni alloy, 304L stainless steel and titanium) in seawater environments. In a first step, the interactions between a model protein, the bovine serum albumin (BSA), and the surface of these materials were investigated. Secondly, tightly bound (TB) and loosely bound (LB) extracellular polymeric substances (EPS), that play a fundamental role in the different stages of biofilm formation, maturation and maintenance, were extracted from Pseudomonas NCIMB 2021 marine strain, and their effects on oxide layers were also evaluated. For that purpose, electrochemical measurements (corrosion potential E(corr) vs time, polarization curves and electrochemical impedance spectroscopy (EIS)) performed during the very first steps of oxide layers formation (1 h immersion time) were combined to surface analysis by X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ions mass spectrometry (ToF-SIMS). Compared to 70Cu-30Ni alloy in static artificial seawater (ASW) without biomolecules, for which a thick duplex oxide layer (outer redeposited Cu2O layer and inner oxidized nickel layer) is shown, the presence of BSA, TB EPS and LB EPS leads to a mixed oxide layer (oxidized copper and nickel) with a lower thickness. In the biomolecules-containing solutions, this oxide layer is covered by an adsorbed organic layer, mainly composed of proteins. A model is proposed to analyse impedance data obtained at E(corr). The results show a slow-down of the anodic reaction in the presence of

  13. Rent Seeking and Corruption in Financial Markets

    OpenAIRE

    Asim Ijaz Khwaja; Atif Mian

    2011-01-01

    We describe recent advances in the study of rent seeking and corruption in financial markets. We outline three areas of inquiry: (a) conceptualizing rent seeking, (b) identifying rent-provision channels and their general equilibrium impact, and (c) designing feasible remedial mechanisms. We provide suggestions for making further progress in these areas and review a variety of approaches taken in the recent literature.

  14. PRISM: a planned risk information seeking model.

    Science.gov (United States)

    Kahlor, LeeAnn

    2010-06-01

    Recent attention on health-related information seeking has focused primarily on information seeking within specific health and health risk contexts. This study attempts to shift some of that focus to individual-level variables that may impact health risk information seeking across contexts. To locate these variables, the researcher posits an integrated model, the Planned Risk Information Seeking Model (PRISM). The model, which treats risk information seeking as a deliberate (planned) behavior, maps variables found in the Theory of Planned Behavior (TPB; Ajzen, 1991) and the Risk Information Seeking and Processing Model (RISP; Griffin, Dunwoody, & Neuwirth, 1999), and posits linkages among those variables. This effort is further informed by Kahlor's (2007) Augmented RISP, the Theory of Motivated Information Management (Afifi & Weiner, 2004), the Comprehensive Model of Information Seeking (Johnson & Meischke, 1993), the Health Information Acquisition Model (Freimuth, Stein, & Kean, 1989), and the Extended Parallel Processing Model (Witte, 1998). The resulting integrated model accounted for 59% of the variance in health risk information-seeking intent and performed better than the TPB or the RISP alone. PMID:20512716

  15. 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…

  16. Students' Help Seeking during Physical Education

    Science.gov (United States)

    Nye, Susan B.

    2008-01-01

    Seeking help with academic tasks has been regarded as an important strategy to enhance student learning (Newman, 1994; Ryan, Gheen, & Midgley, 1998; Zimmerman & Martinez-Pons, 1986). Seeking help is conceptualized as student-initiated efforts to secure task information or solicit advice when a deficiency in their understanding of the content…

  17. 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…

  18. Analysis on Influencing Factors and Mental State in Health Seeking Behavior of Cancer Patients in a Hospital of Guangzhou%广州市某医院肿瘤患者的就医选择影响因素与心理分析

    Institute of Scientific and Technical Information of China (English)

    邱胜; 刘俊荣

    2016-01-01

    Objective: To compare difference of influencing factors and mental state in health seeking behaviors of cancer patients in a hospi-tal in Guangzhou grouped by different economic and sociologist characters.Methods:Questionnaire survey was conducted in a hospital in Guang-zhou and 325 cancer patients was investigated in terms of economic and sociologist characters, factors considered and mental state when going to a hospital.T-test was applied to compare their considered factors and mental state in health seeking behaviors and the respondents were grouped by different health seeking experience, registered permanent residence and income level.Results: Emphasis degrees on medical technical level and services attitude of medical staffs between cancer patients who had or not the experience of hospitalize out-of-line were significantly differ-ent (P<0.05), while anxiety and fear in metal state difference are significant (P<0.05).Emphasis degrees on medical technical level and in-dividual paying ability and visit accessibility between respondents who had different income level (P<0.05), while only fear degree was signifi-cantly different in term mental state (P<0.05).For people who had different registered permanent residence and income level, severity of illness was differently emphasized by them (P<0.05) and they have different dysphonia and fear level, which are statistically significant.Conclusion:People who have higher income and the local registered permanent residence and who have no were experience of hospitalize out-of-line give more emphasis on medical technical level and less emphasis on expenses.While cancer patients who have lower economic and sociologist status are more feared and whiny in the process of seeking health service.Vulnerable groups of cancer patients should be supported by social forces.%目的:探讨广州市某医院不同经济社会学特征的肿瘤患者选择医疗机构时关注的因素及其就医过程中

  19. 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.

  20. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Bjoern Petersen, Steffen; Kold di Gennaro, Ane; Neves-Petersen, Maria Teresa; Skovsen, Esben; Parracino, Antonietta

    2010-10-01

    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, with a fine structured interference pattern superimposed.

  2. Calculation and visualization of atomistic mechanical stresses in nanomaterials and biomolecules.

    Directory of Open Access Journals (Sweden)

    Andrew T Fenley

    Full Text Available Many biomolecules have machine-like functions, and accordingly are discussed in terms of mechanical properties like force and motion. However, the concept of stress, a mechanical property that is of fundamental importance in the study of macroscopic mechanics, is not commonly applied in the biomolecular context. We anticipate that microscopical stress analyses of biomolecules and nanomaterials will provide useful mechanistic insights and help guide molecular design. To enable such applications, we have developed Calculator of Atomistic Mechanical Stress (CAMS, an open-source software package for computing atomic resolution stresses from molecular dynamics (MD simulations. The software also enables decomposition of stress into contributions from bonded, nonbonded and Generalized Born potential terms. CAMS reads GROMACS topology and trajectory files, which are easily generated from AMBER files as well; and time-varying stresses may be animated and visualized in the VMD viewer. Here, we review relevant theory and present illustrative applications.

  3. 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.

  4. 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.

  5. Imparting biomolecules to a metal-organic framework material by controlled DNA tetrahedron encapsulation

    OpenAIRE

    Yongmei Jia; Benmei Wei; Ruixue Duan; Ying Zhang; Boya Wang; Abdul Hakeem; Nannan Liu; Xiaowen Ou; Shaofang Xu; Zhifei Chen; Xiaoding Lou; Fan Xia

    2014-01-01

    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 inte...

  6. 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. PMID:27046460

  7. 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.

  8. Help-seeking atititudes among Israeli adolescents.

    Science.gov (United States)

    Tishby, O; Turel, M; Gumpel, O; Pinus, U; Lavy, S B; Winokour, M; Sznajderman, S

    2001-01-01

    This study investigated the willingness of Israeli adolescents to seek help for emotional and health problems, and their preference for various helping agents. Nearly fifteen hundred students in grades 7-12 participated in a comprehensive survey of attitudes, health status, and concerns, and the data were analyzed. Gender and age were identified as factors associated with help-seeking attitudes. Females reported a higher level of distress and greater willingness to seek help than did males. Younger adolescents tended to state that they would turn to parents for help, whereas older adolescents increasingly preferred peers. In general, the adolescents preferred to seek help from family and peers for emotional and social problems, rather than turning to professionals. Adolescents in grades 9-10 reported the highest level of distress and were least willing to seek help for interpersonal problems and depressed mood. Overall, level of distress was not directly related to willingness to seek help. In subgroups of depressed and suicidal adolescents, an inverse relationship was found between willingness to seek help and levels of depression and suicidal ideation. Recommendations for health care services and counseling programs are discussed. PMID:11572304

  9. Elemental labelling combined with liquid chromatography inductively coupled plasma mass spectrometry for quantification of biomolecules: A review

    OpenAIRE

    Kretschy, Daniela; Koellensperger, Gunda; Hann, Stephan

    2012-01-01

    This article reviews novel quantification concepts where elemental labelling is combined with flow injection inductively coupled plasma mass spectrometry (FI-ICP-MS) or liquid chromatography inductively coupled plasma mass spectrometry (LC–ICP-MS), and employed for quantification of biomolecules such as proteins, peptides and related molecules in challenging sample matrices. In the first sections an overview on general aspects of biomolecule quantification, as well as of labelling will be pre...

  10. 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.

  11. 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.

  12. Targeting cancer with peptide aptamers

    OpenAIRE

    Seigneuric, Renaud; Gobbo, Jessica; Colas, Pierre; Garrido, Carmen

    2011-01-01

    A major endeavour in cancer chemotherapy is to develop agents that specifically target a biomolecule of interest. There are two main classes of targeting agents: small molecules and biologics. Among biologics (e.g.: antibodies), DNA, RNA but also peptide aptamers are relatively recent agents. Peptide aptamers are seldom described but represent attractive agents that can inhibit a growing panel of oncotargets including Heat Shock Proteins. Potential pitfalls and coming challenges towards succe...

  13. 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.

  14. Who's Most Likely to Seek Infertility Help

    Science.gov (United States)

    ... said study leader Jessica Datta. She is a lecturer at the London School of Hygiene & Tropical Medicine ... Those with infertility who did seek help were more likely to be better educated, have higher incomes ...

  15. Particle Swarm Optimization Based Source Seeking

    OpenAIRE

    Zou, Rui; Kalivarapu, Vijay; Winer, Eliot; Oliver, James; Bhattacharya, Sourabh

    2015-01-01

    Signal source seeking using autonomous vehicles is a complex problem. The complexity increases manifold when signal intensities captured by physical sensors onboard are noisy and unreliable. Added to the fact that signal strength decays with distance, noisy environments make it extremely difficult to describe and model a decay function. This paper addresses our work with seeking maximum signal strength in a continuous electromagnetic signal source with mobile robots, using Particle Swarm Opti...

  16. Sensation Seeking, Overconfidence, and Trading Activity

    OpenAIRE

    Mark Grinblatt; Matti Keloharju

    2006-01-01

    This study analyzes the role that two psychological attributes%u2014sensation seeking and overconfidence%u2014play in the tendency of investors to trade stocks. Equity trading data are combined with data from an investor%u2019s tax filings, driving record, and psychological profile. We use the data to construct measures of overconfidence and sensation seeking tendencies. Controlling for a host of variables, including wealth, income, age, number of stocks owned, marital status, and occupation,...

  17. Corporate manslaughter, regulation and 'seeking to profit'

    OpenAIRE

    Kelsey, J.

    2006-01-01

    One of the concepts included in current draft legislation on Corporate Manslaughteris that of seeking to profit. The paper seeks to examine this concept and whether theassumptions underlying it are valid. Firstly the concept is examined in terms ofmanagerial economics where it is argued that there is no necessarily direct trade-offbetween profit and safety expenditure. It is also difficult to disentangle expectation ofprofit and actual profit realisation in relation to a single cost factor. R...

  18. 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...

  19. Predicting job-seeking intensity and job-seeking intention in the sample of unemployed

    OpenAIRE

    Marić Zorica

    2005-01-01

    In this study Ajzen' theory (1991) of planned behavior was used to predict job - seek intention and behavior among unemployed people (N = 650). In addition to theory of planned behavior variables (job - seek attitude, subjective norm, self - efficacy and controllability of job seek process) we used several other psychological (financial pressure, self - mastery, self - esteem and depression) and demographic (gender, age, education, marriage and lent of unemployment) variables to build a model...

  20. 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.

  1. 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.

  2. Study on the preparation and stability of 188Re biomolecules via EHDP

    International Nuclear Information System (INIS)

    A direct labelling technique via ethane-1-hydroxy-1,1-diphosphonic acid (EHDP) as a weak competing ligand was developed for the preparation of several biomolecules: 188 Re-monoclonal antibody ior cea1 against carcinoembryonic antigen (188 Re-MoAb), biotinylated 188Re-MoAb (188 Re-MoAb-biotin), 188 Re-polyclonal IgG (188 Re-IgG), 188 Re-peptide (somatostatine analogue peptide b-(2-naphtyl)-D-Ala-Cys-Tyr-D-Trp-Lys-Val-Cys-Thr-amide), 188 Re-MoAb fragments (188 Re-F(ab')2) and biotinylated 188 Re-F(ab')2 (188 Re-F(ab')2-biotin). The reaction conditions such as pH, temperature, weak ligand concentration and stannous chloride concentration were optimized during the radiolabelling of each biomolecule. Before the labelling procedure, disulphide bridge groups of the biomolecules were reduced with 2-mercaptoethanol (2-ME). To obtain 188 Re labelled antibodies and peptides in high radiochemical yields (>90%) via EHDP, it was necessary to use acidic conditions and a high concentration of stannous chloride to allow the redox reaction Re+7→Re+5:Re+4. The labelling of MoAb and F(ab')2 with 188Re via EHDP was also evaluated employing a pretargeted technique by avidin-biotin strategy in normal mice, demonstrating that the 188Re-labelled biotinylated antibodies are stable complexes in vivo. The 188Re-peptide complex prepared by this method, was stable for 24 h and no radiolytic degradation was observed. (author)

  3. 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.

  4. Brines in seepage channels as eluants for subsurface relict biomolecules on Mars?

    Science.gov (United States)

    Wynn-Williams, D D; Cabrol, N A; Grin, E A; Haberle, R M; Stoker, C R

    2001-01-01

    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 results 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 (approximately 3.5 Ga ago), they would have eluted and concentrated relict biomolecules and delivered 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 degrees C in the interstices of shallow hypersaline soils and at -50 degrees C in salt-saturated ponds. Similarly, hypersaline brines on Mars could have freezing points depressed below -50 degrees 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. PMID:12467120

  5. 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.

  6. Electrokinetic separation of biomolecules through multiple nano-pores on membrane

    Science.gov (United States)

    Kim, Yunho; Cha, Misun; Choi, Yosep; Joo, Hyunsang; Lee, Junghoon

    2013-03-01

    We demonstrate a nanoporous membrane device integrated with an on-chip microfluidic platform for the electrokinetic separation of biomolecules. This platform offers a thin (500 nm) film of anodized aluminum oxide directly fabricated and suspended onto a silicon substrate, assembled into a compact microfluidic device. We successfully showed the electrokinetic transport of ssDNA through the nano-porous membrane under various conditions. Size exclusive biomolecular separation driven by electric field was verified with the complex of thrombin and thrombin aptamer. This architecture enables an on-chip device for binary separation and size exclusive filtration targeted to various applications such as molecular detection and purification.

  7. EPR-based approach for the localization of paramagnetic metal ions in biomolecules.

    Science.gov (United States)

    Abdullin, Dinar; Florin, Nicole; Hagelueken, Gregor; Schiemann, Olav

    2015-02-01

    Metal ions play an important role in the catalysis and folding of proteins and oligonucleotides. Their localization within the three-dimensional fold of such biomolecules is therefore an important goal in understanding structure-function relationships. A trilateration approach for the localization of metal ions by means of long-range distance measurements based on electron paramagnetic resonance (EPR) is introduced. The approach is tested on the Cu(2+) center of azurin, and factors affecting the precision of the method are discussed. PMID:25522037

  8. Extraction of Biomolecules Using Phosphonium-Based Ionic Liquids + K3PO4 Aqueous Biphasic Systems

    OpenAIRE

    Louros, Cláudia L. S.; Cláudio, Ana Filipa M.; Neves, Catarina M. S. S.; Freire, Mara G.; Marrucho, Isabel M.; Jérôme Pauly; Coutinho, João A. P.

    2010-01-01

    Aqueous biphasic systems (ABS) provide an alternative and efficient approach for the extraction, recovery and purification of biomolecules through their partitioning between two liquid aqueous phases. In this work, the ability of hydrophilic phosphonium-based ionic liquids (ILs) to form ABS with aqueous K3PO4 solutions was evaluated for the first time. Ternary phase diagrams, and respective tie-lines and tie-lines length, formed by distinct phosphonium-based ILs, water, and K3PO4 at 298 K, we...

  9. 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

  10. 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

  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. 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.

  13. 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. PMID:27211240

  14. 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...

  15. Does Context Matter? Examining PRISM as a Guiding Framework for Context-Specific Health Risk Information Seeking Among Young Adults.

    Science.gov (United States)

    Willoughby, Jessica Fitts; Myrick, Jessica Gall

    2016-06-01

    Research indicates that when people seek health information, they typically look for information about a specific symptom, preventive measure, disease, or treatment. It is unclear, however, whether general or disease-specific theoretical models best predict how people search for health information. We surveyed undergraduates (N = 963) at a large public southeastern university to examine health information seeking in two incongruent health contexts (sexual health and cancer) to test whether a general model would hold for specific topics that differed in their immediate personal relevance for the target population. We found that the planned risk information seeking model was statistically a good fit for the data. Yet multiple predicted paths were not supported in either data set. Certain variables, such as attitudes, norms, and affect, appear to be strong predictors of intentions to seek information across health contexts. Implications for theory building, research methodology, and applied work in health-related risk information seeking are discussed. PMID:27187057

  16. Dealing with drug-seeking behaviour.

    Science.gov (United States)

    James, Jenny

    2016-06-01

    People who misuse prescription drugs most commonly seek prescriptions for opioids and benzodiazepines. Other prescription drugs that are misused include the newer antipsychotics such as quetiapine and olanzapine, and stimulants such as dexamphetamine and methylphenidate. Health professionals should be aware of behaviours that may indicate drug seeking, but dependency on prescription drugs can occur at any age, within any cultural group and across any educational class. Patients with dependencies may not necessarily display obvious drug-seeking behaviours. All general practices should have a practice policy on prescribing drugs of dependence. GPs should register with the Prescription Shopping Information Service. There is strong evidence in Australia of increasing harms from prescription drugs of dependence, including deaths from overdose. Before prescribing any drug of dependence, health professionals require an understanding of the patient's biopsychosocial status, and the evidence-based indications and potential significant harms of these drugs. PMID:27346918

  17. Labelling techniques of biomolecules for targeted radiotherapy. Final report of a co-ordinated research project 1998-2002

    International Nuclear Information System (INIS)

    Malignant tumour disease accounts for approximately one third of deaths worldwide. Gastrointestinal adenocarcinomas, prostate and breast cancers are among the most frequently appearing tumours. Radiotherapy is an essential mode of treatment of all cancer patients either alone or in conjunction with other modalities like surgery and chemotherapy. In most cases radiotherapy is given using external radiation sources. It is also possible to administer radiotherapy by specifically localizing radioisotopes emitting particulate radiation in the tumour tissue. This targeted therapy has proved to have several advantages over external beam therapy, notably the possibility of selectively delivering higher radiation doses to the targeted tumour cells and treating multiple metastases. Procedures for therapy of thyroid carcinoma and hyper-thyroidism using radioiodine (131I) introduced about five decades ago, have stood the test of time and are still widely used the world over. In addition to the therapeutic nuclides of the first generation 131I, 89Sr, 32P, 90Y, etc., which are still widely utilized and accepted by the medical community, many other beta emitting radionuclides with relatively short half-lives such as 153Sm, 186Re, 188Re, 166Ho, 165Dy, etc. have also been recently made available for therapy and used with promising good results. In spite of the potential of targeted radiotherapy to treat a wide range of malignant conditions, routine clinical use is mostly confined to therapy of thyroid carcinoma, hyperthyroidism, metastatic bone pain and synovectomy. In most of the cases, the limitation is obviously not the availability of suitable radionuclides but rather the lack of suitable carrier molecules that would adequately concentrate these radionuclides in target tissues of interest. Based on the above considerations, the scope of the Co-ordinated Research Project (CRP) has focused on the synthesis of the required BFCAs for MoAbs and peptide labelling, development and

  18. Measuring Help-Seeking Intentions: Properties of the General Help Seeking Questionnaire

    Science.gov (United States)

    Wilson, Coralie J.; Deane, Frank P.; Ciarrochi, Joseph; Rickwood, Debra

    2005-01-01

    Understanding help seeking intentions and behaviour is fundamental to the identification of factors that can be modified to increase engagement in counselling. Despite considerable research on these variables, integrating prior research has been impeded by a lack of consistent and psychometrically sound help-seeking measures. The General…

  19. 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...... experience many search problems, such as the lack of specificity, differences in the interpretation of the topics of documents, and unwieldy and irrelevant search results. These problems can be solved by a combination of improved indexing practices and search features....

  20. 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.

  1. 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.

  2. 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

    2015-08-01

    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.

  3. Highly Sensitive Detection of Target Biomolecules on Cell Surface Using Gold Nanoparticle Conjugated with Aptamer Probe

    Science.gov (United States)

    Kim, Hyonchol; Terazono, Hideyuki; Hayashi, Masahito; Takei, Hiroyuki; Yasuda, Kenji

    2012-06-01

    A method of gold nanoparticle (Au NP) labeling with backscattered electron (BE) imaging of field emission scanning electron microscopy (FE-SEM) was applied for specific detection of target biomolecules on a cell surface. A single-stranded DNA aptamer, which specifically binds to the target molecule on a human acute lymphoblastic leukemia cell, was conjugated with a 20 nm Au NP and used as a probe to label its target molecule on the cell. The Au NP probe was incubated with the cell, and the interaction was confirmed using BE imaging of FE-SEM through direct counting of the number of Au NPs attached on the target cell surface. Specific Au NP-aptamer probes were observed on a single cell surface and their spatial distributions including submicron-order localizations were also clearly visualized, whereas the nonspecific aptamer probes were not observed on it. The aptamer probe can be potentially dislodged from the cell surface with treatment of nucleases, indicating that Au NP-conjugated aptamer probes can be used as sensitive and reversible probes to label target biomolecules on cells.

  4. 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.

  5. 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.

  6. Liquid-liquid extraction of biomolecules in downstream processing - A review paper

    Directory of Open Access Journals (Sweden)

    Silva M. E.

    2000-01-01

    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.

  7. Photoelectrochemical studies of DNA-tagged biomolecules on Au and Au/Ni/Au multilayer nanowires

    Directory of Open Access Journals (Sweden)

    Swaminathan Viswanathan

    2011-01-01

    Full Text Available Abstract The use of nanowires (NWs for labeling, sensing, and sorting is the basis of detecting biomolecules attached on NWs by optical and magnetic properties. In spite of many advantages, the use of biomolecules-attached NWs sensing by photoelectrochemical (PEC study is almost non-existent. In this article, the PEC study of dye-attached single-stranded DNA on Au NWs and Au-Ni-Au multilayer NWs prepared by pulse electrodeposition are investigated. Owing to quantum-quenching effect, the multilayer Au NWs exhibit low optical absorbance when compared with Au NWs. The tagged Au NWs show good fluorescence (emission at 570 nm, indicating significant improvement in the reflectivity. Optimum results obtained for tagged Au NWs attached on functionalized carbon electrodes and its PEC behavior is also presented. A twofold enhancement in photocurrent is observed with an average dark current of 10 μA for Au NWs coated on functionalized sensing electrode. The importance of these PEC and optical studies provides an inexpensive and facile processing platform for Au NWs that may be suitable for biolabeling applications.

  8. 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.

  9. Simplified TiO2 force fields for studies of its interaction with biomolecules

    Science.gov (United States)

    Luan, Binquan; Huynh, Tien; Zhou, Ruhong

    2015-06-01

    Engineered TiO2 nanoparticles have been routinely applied in nanotechnology, as well as in cosmetics and food industries. Despite active experimental studies intended to clarify TiO2's biological effects, including potential toxicity, the relation between experimentally inferred nanotoxicity and industry standards for safely applying nanoparticles remains somewhat ambiguous with justified concerns. Supplemental to experiments, molecular dynamics simulations have proven to be efficacious in investigating the molecular mechanism of a biological process occurring at nanoscale. In this article, to facilitate the nanotoxicity and nanomedicine research related to this important metal oxide, we provide a simplified force field, based on the original Matsui-Akaogi force field but compatible to the Lennard-Jones potentials normally used in modeling biomolecules, for simulating TiO2 nanoparticles interacting with biomolecules. The force field parameters were tested in simulating the bulk structure of TiO2, TiO2 nanoparticle-water interaction, as well as the adsorption of proteins on the TiO2 nanoparticle. We demonstrate that these simulation results are consistent with experimental data/observations. We expect that simulations will help to better understand the interaction between TiO2 and molecules.

  10. Biomolecules preserved in ca. 168 million year old fossil conifer wood

    Science.gov (United States)

    Marynowski, Leszek; Otto, Angelika; Zatoń, Michał; Philippe, Marc; Simoneit, Bernd R. T.

    2007-03-01

    Biomarkers are widely known to occur in the fossil record, but the unaltered biomolecules are rarely reported from sediments older than Paleogene. Polar terpenoids, the natural products most resistant to degradation processes, were reported mainly from the Tertiary conifers, and the oldest known are Cretaceous in age. In this paper, we report the occurrence of relatively high concentrations of ferruginol derivatives and other polar diterpenoids, as well as their diagenetic products, in a conifer wood Protopodocarpoxylon from the Middle Jurassic of Poland. Thus, the natural product terpenoids reported in this paper are definitely the oldest polar biomolecules detected in geological samples. The extracted phenolic abietanes like ferruginol and its derivatives (6,7-dehydroferruginol, sugiol, 11,14-dioxopisiferic acid) are produced only by distinct conifer families (Cupressaceae s. l., Podocarpaceae and Araucariaceae), to which Protopodocarpoxylon could belong based on anatomical characteristics. Therefore, the natural product terpenoids are of great advantage in systematics of fossil plant remains older than Paleogene and lacking suitable anatomical preservation.

  11. 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.

  12. Synchrotron and small bio-molecules in gas phase and liquid environment: new opportunities in Brazil

    International Nuclear Information System (INIS)

    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)

  13. Biospecimen Solicitation - Office of Cancer Clinical Proteomics Research

    Science.gov (United States)

    A funding opportunity in support of the National Cancer Institute’s Clinical Proteomic Tumor Analysis Consortium (CPTAC) seeks to prospectively procure tumor samples, collected for proteomics investigation.

  14. Computer Conferencing: Its Impact on Academic Help-Seeking.

    Science.gov (United States)

    Karabenick, Stuart A.

    Arguing that seeking help when needed is an integral part of the learning process, this paper describes a three-stage help-seeking process; examines computer conferencing in academic contexts; and describes several characteristics that promote help-seeking, including the admission of inadequacy, the decision to seek help, and the ultimate…

  15. 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…

  16. 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.…

  17. 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.)…

  18. 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.

  19. 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

  20. Seeking Understanding by Which to Educate

    Science.gov (United States)

    Hill, Brian V.

    2009-01-01

    In retrospect, Anselm's motto "fides quaerens intellectum" (faith seeking understanding) could fairly be taken to reflect the author's life's journey, beginning with a period of intellectual rebellion against the faith of his Methodist parents as he was entering adolescence. At the age of 14, however, in a revelatory moment, and unbeknown to…

  1. Does Risk Seeking drive Asset Prices?

    NARCIS (Netherlands)

    G.T. Post (Thierry); H. Levy (Haim)

    2002-01-01

    textabstractWe investigate whether risk seeking or non-concave utility functions can help to explain the cross-sectional pattern0 of stock returns. For this purpose, we analyze the stochastic dominance efficiency classification of the value-weighted market portfolio relative to benchmark portfolios

  2. Help Seeking in English Language Learning

    Science.gov (United States)

    Skinner, Barbara; Madden, Mary Catherine

    2010-01-01

    An examination of literature on the issue of help seeking (HS) has revealed a common theme: students will not always ask for help, even when they are aware that help is needed. The purpose of this action research study was to examine HS and help avoidance in the context of setting tasks in two types of English language-learning environment: a…

  3. Memory complaints associated with seeking clinical care

    NARCIS (Netherlands)

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

    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

  4. 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;…

  5. Micropatterning of biomolecules on a glass substrate in fused silica microchannels by using photolabile linker-based surface activation

    International Nuclear Information System (INIS)

    We report on a straightforward method for creating micropatterns of multiple biomolecules. The anti-fouling agent 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer and a photolabile linker (PL) were covalently linked to an amino-terminated silane surface. Patterns were generated by selective removal of the MPC polymer via UV irradiation. Multiple micropatterns of fluorescein isothiocyanate (FITC)-labeled bovine serum albumin (BSA) and rhodamine-labeled goat fragment antigen-binding fragments (FAB) were deposited on a same glass substrate. We also employed micropatterning of multiple biomolecules in that Texas red-labeled BSA and FITC-labeled rabbit anti-mouse IgG were placed inside a microchannel. (author)

  6. Cancer Basics

    Science.gov (United States)

    ... Cancer? Breast Cancer Colon/Rectum Cancer Lung Cancer Prostate Cancer Skin Cancer Show All Cancer Types News and Features Cancer Glossary ACS Bookstore Cancer Information Cancer Basics Cancer Prevention & Detection Signs & Symptoms of Cancer Treatments & Side Effects ...

  7. 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

  8. 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

  9. 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

  10. 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. PMID:26168991

  11. 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.

  12. Latent analysis of unmodified biomolecules and their complexes in solution with attomole detection sensitivity

    Science.gov (United States)

    Yates, Emma V.; Müller, Thomas; Rajah, Luke; de Genst, Erwin J.; Arosio, Paolo; Linse, Sara; Vendruscolo, Michele; Dobson, Christopher M.; Knowles, Tuomas P. J.

    2015-10-01

    The study of biomolecular interactions is central to an understanding of function, malfunction and therapeutic modulation of biological systems, yet often involves a compromise between sensitivity and accuracy. Many conventional analytical steps and the procedures required to facilitate sensitive detection, such as the incorporation of chemical labels, are prone to perturb the complexes under observation. Here we present a ‘latent’ analysis approach that uses chemical and microfluidic tools to reveal, through highly sensitive detection of a labelled system, the behaviour of the physiologically relevant unlabelled system. We implement this strategy in a native microfluidic diffusional sizing platform, allowing us to achieve detection sensitivity at the attomole level, determine the hydrodynamic radii of biomolecules that vary by over three orders of magnitude in molecular weight, and study heterogeneous mixtures. We illustrate these key advantages by characterizing a complex of an antibody domain in the solution phase and under physiologically relevant conditions.

  13. 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.

  14. 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

    The ability of matrix-assisted pulsed laser evaporation (MAPLE) technique to transfer and deposit high-quality thin organic, bioorganic, and composite films with minimum chemical modification of the target material has been utilized in numerous applications. One of the outstanding problems in MAPLE...... film deposition, however, is the presence of residual solvent (matrix) codeposited with the polymer material and adversely affecting the quality of the deposited films. In this work, we investigate the possibility of alleviating this problem by reducing the amount of matrix in the target. A series...... 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...

  15. The interplay of biomolecules and water at the origin of the active behavior of living organisms

    International Nuclear Information System (INIS)

    It is shown that the main component of living matter, namely liquid water, is not an ensemble of independent molecules but an ensemble of phase correlated molecules kept in tune by an electromagnetic (e.m) field trapped in the ensemble. This field and the correlated potential govern the interaction among biomolecules suspended in water and are in turn affected by the chemical interactions of molecules. In particular, the phase of the coherent fields appears to play an important role in this dynamics. Recent experiments reported by the Montagnier group seem to corroborate this theory. Some features of the dynamics of human organisms, as reported by psychotherapy, holistic medicine and Eastern traditions, are analyzed in this frame and could find a rationale in this context.

  16. Measurement of small photodestruction rates of cold, charged biomolecules in an ion trap

    CERN Document Server

    Offenberg, D; Zhang, C B; Roth, B; Schiller, S

    2008-01-01

    In this work, we demonstrate measurements of photodestruction rates of translationally cold, charged biomolecules. The long-term stable storage of the molecular ions in an ion trap at ultra-high vacuum conditions allows measurement of small rates and verification that rates are linear in photodestruction laser intensity. Measurements were performed on singly protonated molecules of the organic compound glycyrrhetinic acid (C30H46O4), dissociated by a continuous-wave UV laser (266 nm) using different intensities. The molecules were sympathetically cooled by simultaneously trapped laser-cooled barium ions to translational temperatures of below 150 mK. Destruction rates of less than 0.05 s^-1 and a cross section of (1.1 +/- 0.1) * 10^-17 cm^2 have been determined. An extension to tunable UV laser sources would permit high-resolution dissociation spectroscopic studies on a wide variety of cold complex molecules.

  17. 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.

  18. Elemental speciation in biomolecules by LC-ICP-MS with magnetic sector and collision cell instruments

    International Nuclear Information System (INIS)

    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. Elemental speciation in biomolecules by LC-ICP-MS with magnetic sector and collision cell instruments

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jin

    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.

  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. Structural Change of Biomolecules and Application of Synergistic Interaction by Radiation

    International Nuclear Information System (INIS)

    It is expected that motivation and basic technologies for the future R and D plans can be provided from the results of this study. This study has been done to develop fundamentals for radiation applications based on the existing radiation technology, and to establish technical basis for enhancing efficacy of radiation utilization by studying the simultaneous application of ionizing radiation with another factor. Application of radiation technology together with the existing technologies to enhance the physical, chemical, biological characteristics through structural changes of biomolecules will exert a favorable influence on the creation of de novo scientific and industrial values. A theoretical model for the combined action of ionizing radiation with another factor can make it possible to predict a prior the maximum value of synergistic interaction and the conditions for it. Furthermore, the results of this study give a clues for establishment of fundamental theories associated with positive efficacy of radiation applications

  2. 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.

  3. 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.

  4. A comparison of risk factors for women seeking labiaplasty compared to those not seeking labiaplasty

    OpenAIRE

    Veale, David; Eshkevari, Ertimiss; Ellison, Nell; Costa, Ana; Robinson, Dudley; KAVOUNI, ANGELICA; Cardozo, Linda

    2014-01-01

    Little is known about the factors associated with the desire for labiaplasty. We compared 55 women seeking labiaplasty with 70 women in a comparison group who were not seeking labiaplasty. Measures administered included the Perception of Appearance and Competency Related Teasing Scale, Childhood Trauma Questionnaire, Disgust Scale Revised, and the Genital Appearance Satisfaction scale with open-ended questions about their genitalia. Approximately a third of the labiaplasty group recalled spec...

  5. 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.

  6. 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...

  7. Vertical Differentiation with Variety-Seeking Consumers

    OpenAIRE

    Robert Zeithammer; Raphael Thomadsen

    2013-01-01

    We analyze price and quality competition in a vertically differentiated duopoly in which consumers have a preference for variety. The preference for variety is a consequence of diminishing marginal utility for repeated experiences with the same product. We find consumer variety seeking can either soften or intensify price competition, depending on the difference in firm qualities and the strength of consumer preference for variety. When the qualities are similar (or the consumer preference fo...

  8. Attitudes Toward Seeking Financial Counseling: Instrument Development

    OpenAIRE

    Cook, Janeen

    1987-01-01

    The purpose of this research was to establish the validity and reliability of the scores on an instrument which assesses attitudes toward seeking help for financial problems . Content, criterion-related, and construct validit y and internal consistency reliability of the scores on the instrument were examined. The Hughes' conceptual model of the Family in Financial Crisis provided the theoretical basis for this study . The sample size of this study was 510. The instrument evaluated was based ...

  9. 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.

  10. 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.

  11. 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.

  12. Elemental labelling combined with liquid chromatography inductively coupled plasma mass spectrometry for quantification of biomolecules: A review

    International Nuclear Information System (INIS)

    Highlights: ► Survey of bio-analytical approaches utilizing biomolecule labelling. ► Detailed discussion of methodology and chemistry of elemental labelling. ► Biomedical and bio-analytical applications of elemental labelling. ► FI-ICP-MS and LC–ICP-MS for quantification of elemental labelled biomolecules. ► Review of selected applications. - Abstract: This article reviews novel quantification concepts where elemental labelling is combined with flow injection inductively coupled plasma mass spectrometry (FI-ICP-MS) or liquid chromatography inductively coupled plasma mass spectrometry (LC–ICP-MS), and employed for quantification of biomolecules such as proteins, peptides and related molecules in challenging sample matrices. In the first sections an overview on general aspects of biomolecule quantification, as well as of labelling will be presented emphasizing the potential, which lies in such methodological approaches. In this context, ICP-MS as detector provides high sensitivity, selectivity and robustness in biological samples and offers the capability for multiplexing and isotope dilution mass spectrometry (IDMS). Fundamental methodology of elemental labelling will be highlighted and analytical, as well as biomedical applications will be presented. A special focus will lie on established applications underlining benefits and bottlenecks of such approaches for the implementation in real life analysis. Key research made in this field will be summarized and a perspective for future developments including sophisticated and innovative applications will given.

  13. 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.

  14. Distribution of Biomolecules in Porous Nitrocellulose Membrane Pads Using Confocal Laser Scanning Microscopy and High-Speed Cameras

    NARCIS (Netherlands)

    Mujawar, Liyakat Hamid; Maan, Abid Aslam; Khan, Muhammad Kashif Iqbal; Norde, Willem; van Amerongen, Aart

    2013-01-01

    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 mor

  15. 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...

  16. Fragmentation study of isolated and nano-solvated biomolecules induced by collision with multiply charged ions and neutral particles

    International Nuclear Information System (INIS)

    This thesis concerns a gas phase study of the fragmentation of bio-molecular systems induced by slow collisions with multiply charged ions (in the keV-region), alkali atoms and rare gases. The main objective was to study the physical processes involved in the dissociation of highly electronically excited systems. In order to elucidate the intrinsic properties of certain biomolecules (porphyrins and amino acids) we have performed experiments in the gas phase with isolated systems. The obtained results demonstrate the high stability of porphyrins after electron removal and attachment. Furthermore, a dependence of the fragmentation pattern produced by multiply charged ions on the isomeric structure of the alanine molecule has been shown. In a second part of the thesis, a strong influence of the environment of the biomolecule on the fragmentation channels, their modification and their new opening, has been clearly proven. This phenomenon occurs in the presence of other surrounding biomolecules (clusters of nucleobases) as well as for molecules of a solvent (molecules of water, methanol and acetonitrile) in which the biomolecule is embedded. In order to extend these studies to larger systems, a new experimental set-up, based on an electro-spray ion source combined with a quadrupole mass filter has been developed. Due to the successful tests and proposed improvements of the device future experiments will become available concerning the fragmentation of large charged and solvated bio-molecular systems induced by collision processes. (author)

  17. Insomnia patients' help-seeking experiences.

    Science.gov (United States)

    Cheung, Janet M Y; Bartlett, Delwyn J; Armour, Carol L; Glozier, Nicholas; Saini, Bandana

    2014-03-01

    Timely access to appropriate treatment is important for optimizing insomnia management. To date, little is known about insomnia patients' treatment experiences or how they access and engage with the available health care resources. This study sought to capture the help-seeking experiences and behavioral patterns of patients with insomnia who are seeking or receiving specialist care. A purposive sample of 26 insomnia patients from specialist sleep and mental health clinics located in metropolitan New South Wales, Australia was recruited. Participants completed a brief questionnaire, followed by an in-depth, semi-structured interview. Interviews were digitally recorded, transcribed verbatim, and analyzed using framework analysis. Three key themes emerged from the data: patients' sleep beliefs, treatment beliefs, and accessing specialized care. The findings show that daytime symptoms arising from insomnia serve as important illness cues for patients to seek medical help. In addition, participants' treatment pathways highlight factors that prevent the widespread use of cognitive behavioral therapy for insomnia (CBT-I), including limited awareness about CBT-I, tentative referral mechanisms, limited service providers, and the high cost of CBT-I. PMID:23514322

  18. Surprising decline in consumers seeking health information.

    Science.gov (United States)

    Tu, Ha T

    2011-11-01

    In 2010, 50 percent of American adults sought information about a personal health concern, down from 56 percent in 2007, according to a new national study from the Center for Studying Health System Change (HSC). The likelihood of people seeking information from the Internet and from friends and relatives changed little between 2007 and 2010, but their use of hardcopy books, magazines and newspapers dropped by nearly half to 18 percent. While the reduced tendency to seek health information applied to consumers across nearly all demographic categories, it was most pronounced for older Americans, people with chronic conditions and people with lower-education levels. Across all individual characteristics, education level remained the factor most strongly associated with con­sumers' inclination to seek health information. Consumers who actively researched health concerns widely reported positive impacts: About three in five said the information affected their overall approach to maintaining their health, and a similar proportion said the information helped them to better understand how to treat an illness or condition. PMID:22121566

  19. 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.

  20. Clinical Assay Development Support - Office of Cancer Clinical Proteomics Research

    Science.gov (United States)

    The NCI’s Division of Cancer Treatment and Diagnosis and the Cancer Diagnosis Program announce a request for applications for the Clinical Assay Development Program (CADP) for investigators seeking clinical assay development and validation resources.

  1. 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. PMID:27093497

  2. 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.

  3. From Resistance to Opportunity-Seeking

    DEFF Research Database (Denmark)

    Gjerdrum Pedersen, Esben Rahbek; Gwozdz, Wencke

    2014-01-01

    Using survey responses from 400 fashion companies in Denmark, Norway, Sweden, Finland, and Iceland, we examine the diversity of strategic responses to institutional pressures for corporate social responsibility (CSR) within the Nordic fashion industry. We also develop and test a new model...... of strategic responses to institutional pressures that encompasses both resistance and opportunity-seeking behaviour. Our results suggest that it is inconsistent pressures within, rather than between, stake-holder groups that shape strategic responses to CSR pressures and that increasing pressures stimulates...

  4. Seeking Lorentz Violation from the Higgs

    CERN Document Server

    Cohen, Andrew; Xu, Yiming

    2014-01-01

    The recently discovered Higgs particle with a mass near $126$ GeV presents new opportunities to explore Lorentz violation. Ultra-high-energy cosmic rays are one of the most sensitive testing grounds for Lorentz symmetry, and can be used to seek for and limit departures from Lorentz invariance in the Higgs sector. If the Higgs were to have a super- or sub-luminal maximal speed both Higgs and weak interaction physics would be modified. Consideration of such modifications allow us to constrain the Higgs maximal velocity to agree with that of other Standard Model particles to parts in $10^{14}$.

  5. The information-seeking practices of engineers

    DEFF Research Database (Denmark)

    Hertzum, M.; Pejtersen, A. M.

    2000-01-01

    Engineers get most of their information from colleagues and internal reports. This study investigates how engineers' information-seeking practices intertwine looking for informing documents with looking for informed people. Based on case studies in two product-development organisations we find...... that engineers search for documents to find people, search for people to get documents, and interact socially to get information without engaging in explicit searches, This intricate interplay between document and people sources can be explained by the nature of the design task, Many possible solutions...... Elsevier Science Ltd. All rights reserved....

  6. Information seeking behaviour of online museum visitors

    DEFF Research Database (Denmark)

    Skov, Mette

    There is a current trend to make museum collections widely accessible by digitising cultural heritage collections for the Internet. At the same time we know very little of how remote access users interact with the collections and their motivations for visiting. This talk will present results from...... 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...

  7. A comparison of risk factors for women seeking labiaplasty compared to those not seeking labiaplasty.

    Science.gov (United States)

    Veale, David; Eshkevari, Ertimiss; Ellison, Nell; Costa, Ana; Robinson, Dudley; Kavouni, Angelica; Cardozo, Linda

    2014-01-01

    Little is known about the factors associated with the desire for labiaplasty. We compared 55 women seeking labiaplasty with 70 women in a comparison group who were not seeking labiaplasty. Measures administered included the Perception of Appearance and Competency Related Teasing Scale, Childhood Trauma Questionnaire, Disgust Scale Revised, and the Genital Appearance Satisfaction scale with open-ended questions about their genitalia. Approximately a third of the labiaplasty group recalled specific negative comments in the past towards their labia, a proportion significantly greater than the three per cent in the comparison group. Participants reporting genital teasing also showed higher Genital Appearance Satisfaction scores than those who were not teased. However, women seeking labiaplasty were, compared to the comparison group, no more likely to have a history of neglect or abuse during childhood. There was no difference between the groups on disgust sensitivity or the perception of being teased in the past about their competence or appearance in general. PMID:24239491

  8. On-chip micro-electromagnets for magnetic-based bio-molecules separation

    Energy Technology Data Exchange (ETDEWEB)

    Ramadan, Qasem E-mail: qasem@pmail.ntu.edu.sg; Samper, Victor; Poenar, Daniel; Yu Chen

    2004-10-01

    This paper reports a comprehensive theoretical, finite element and measurement analysis of different designs of planar micro-electromagnets for bio-molecular manipulation. The magnetic field due to current flowing in complex shapes of current-carrying conductors have been calculated analytically, simulated using finite-element analysis (FEA), and measured using the superconducting quantum interference device technique (SQUID). A comparison of the theoretical and measured magnetic field strength and patterns is presented. The planar electromagnets have been fabricated using patterned Al 2 {mu}m thick. The aim of the study is to explore and optimize the geometrical and structural parameters of planar electromagnets that give rise to the highest magnetic fields and forces for magnetic micro-beads manipulation. Magnetic beads are often used in biochemical assays for separation of bio-molecules. Typical beads are 0.2-10 {mu}m in diameter and have superparamagnetic properties. Increasing the intensity of the magnetic field generated by a coil by injection a larger current is not the most suitable solution as the maximum current is limited by Joule heating. Consequently, in order to maximize the field for a given current, one should optimize the geometry of the coil, as this is an extremely significant factor in determining the magnetic field intensity in 2D planar designs. The theoretical and measured results of this work show that the meander micro-electromagnet with mesh-shaped winding profile produces the strongest magnetic field (about 2.7 {mu}T for a current intensity of 6 mA) compared with other meander designs, such as the serpentine and rosette-shaped ones. The magnetic fields of these three types of meander-shaped micro-electromagnets were compared theoretically with that produced by a spiral micro-electromagnet whose technological realization is more complicated and costly due to the fact that it requires an additional insulation layer with a contact window and

  9. 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

  10. Bacterial toxicity of oxide nanoparticles and their effects on bacterial surface biomolecules

    Science.gov (United States)

    Jiang, Wei

    Toxicity of nano-scaled Al2O3, SiO2, TiO2 and ZnO to bacteria (Bacillus subtilis, Escherichia coli and Pseudomonas fluorescens) was examined and compared to that of their respective bulk (micro-scaled) counterparts. All nanoparticles (NPs) but TiO2 showed higher toxicity than their bulk counterparts. Toxicity of released metal ions was differentiated from that of the oxide particles. ZnO was the most toxic among the three NPs, causing 100% mortality to the three tested bacteria. TEM images showed attachment of NPs to the bacteria, suggesting that the toxicity was affected by bacterial attachment. The effects of oxide NPs on bacteria cells and bacterial surface biomolecules were studied by FTIR spectroscopy to provide a better understanding of their cytotoxicity. Lipopolysaccharide (LPS) and lipoteichoic acid could bind to oxide NPs through hydrogen bonding and ligand exchange, but the cytotoxicity of NPs seemed largely related to the function-involved or structural changes to proteins and phospholipids. The three NPs decreased the intensity ratio of beta-sheets/alpha-helices, indicating protein structure change, which may affect cell physiological activities. The phosphodiester bond of L-alpha-Phosphatidyl-ethanolamine (PE) was broken by ZnO NPs, forming phosphate monoesters and resulting in the highly disordered alkyl chain. Such damage to phospholipid molecular structure may lead to membrane rupture and cell leaking, which is consistent with the fact that ZnO is the most toxic of the three NPs. LPS and PE are amphiphilic biomolecules that are major constituents of the outer membrane of Gram-negative bacteria. Their micelles and vesicles were studied as model cell membranes to evaluate NP effects on membrane construction. The adsorption of polysaccharides on Al2O3 and TiO 2 NPs dispersed LPS vesicles and micelles. LPS coated Al2O 3 NPs, while it caused the aggregation of TiO2 NPs according to atom force microscopy images. Desorption from the two NPs was slow due

  11. Patterns between Interactive Intentions and Information-Seeking Strategies.

    Science.gov (United States)

    Xie, Hong (Iris)

    2002-01-01

    Discusses information retrieval system design that supports various information-seeking strategies. Describes a study that investigated the relationship between users' information-seeking goals and their information-seeking behavior to specify hierarchical levels of user goals, and discusses results that focus on patterns of interactive intentions…

  12. Motivational Dynamics of Children's Academic Help-Seeking and Concealment

    Science.gov (United States)

    Marchand, Gwen; Skinner, Ellen A.

    2007-01-01

    Models of self-regulated learning and of children's coping both consider help-seeking an adaptive response to academic problems, yet students do not always seek help when it is needed, and help-seeking generally declines across early adolescence. A study of 765 children in elementary and middle school (Grades 3-6) during fall and spring of the…

  13. Academic Help-Seeking and Peer Relations in School.

    Science.gov (United States)

    Nelson-LeGall, Sharon; Glor-Scheib, Susan

    1986-01-01

    This study investigated the relationship between peer relations and help-seeking behaviors in third- and fifth-grade boys and girls. The relationship between peer status and academic help-seeking was found to vary with the target of the help-seeking overture and the type of help requested. (Author/LMO)

  14. Attitudes of Male Prisoners toward Seeking Professional Psychological Help.

    Science.gov (United States)

    Williams, Mei Wah; Skogstad, Philip; Deane, Frank P.

    2001-01-01

    Examines whether prisoners seek help from mental health professionals, and assesses the validity and utility of a short form of the Attitudes Toward Seeking Professional Psychological Help Scale (ATSPPHS) for assessing prison inmates' help-seeking attitudes. Results were consistent with previous research, and indicated that male inmates (N = 173)…

  15. 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.

  16. 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.

  17. Physician information seeking: improving relevance through research.

    Science.gov (United States)

    Gruppen, L D

    1990-04-01

    Health sciences libraries have considerable potential as resources for both formal continuing professional education, as well as the informal continuing education that results from the professional's efforts to solve problems in daily practice. While there is a growing interest in making the resources of health sciences libraries more accessible to practitioners on a routine, day-to-day basis, there also needs to be more awareness of how, when, where, and why professionals look for information in the context of practical problems. This paper reviews recent research that identifies the context in which physicians seek information and advice from external sources, the information sources that physicians access, and the factors that influence which particular sources are sought. The results indicate that physicians vary in their information needs, preferences, motivations, and strategies for seeking information. This diversity suggests that health sciences libraries, in their efforts to be more accessible, should consider "market research" to determine the needs, preferences, and use patterns of the library's targeted users. Libraries may also benefit from exploring alternative methods of improving access to their resources. PMID:2183904

  18. Theoretical and experimental proof of the accumulating transfer of tritium from water into DNA and other biomolecules in vitro and in vivo

    International Nuclear Information System (INIS)

    Heisenberg's Uncertainity Relation leads to the conclusion, tritium accumulates in the exchangeable hydrogen positions of biomolecules if it is administered in the state of water. Appropriate tests of fishsperm DNA and the biomolecules of piglet's liver resulted in a fractionation factor of about 2 favouring such organically bound tritium. Furthermore, a fractionation factor of 1.4 is found in the hydration sheet of the biomolecules. The logistic growth analysis of maize and barley confirms the accumulation of tritium from water in the tissue solids of the plants. (orig.)

  19. Intention to seek professional psychological help among college students in Turkey: influence of help-seeking attitudes

    OpenAIRE

    Seyfi, Feyza; Poudel, Krishna C.; Yasuoka, Junko; Otsuka, Keiko; Jimba, Masamine

    2013-01-01

    Background Depression rates are high among college students in Turkey, but often students do not seek mental health care. This study aimed to examine the association between attitudes toward seeking professional psychological help and intention to seek professional psychological help among such college students. We also examined the factors associated with students’ professional psychological help-seeking attitudes. We conducted this cross-sectional study among 456 conveniently sampled gradua...

  20. Information Seeking Anxiety: Concept, Measurement and Preliminary Research

    Directory of Open Access Journals (Sweden)

    Mohammadamin Erfanmanesh

    2013-12-01

    Full Text Available This study aims to introduce the information seeking anxiety construct as a phenomenon among postgraduate students. It also presents the Information Seeking Anxiety Scale (ISAS as a valid and reliable instrument. Further, the current study investigates the prevalence of information seeking anxiety among postgraduate students at a research-intensive university in Kuala Lumpur, Malaysia. Results of the study revealed that while information seeking anxiety is present among the studied students, the overall level is not high. Additionally, Different levels (low, mild, moderate and severe levels of the information seeking anxiety construct were reported to have experienced by 96.5% of the postgraduate students at the sampled university.

  1. Extracting biomolecule collision cross sections from the high-resolution FT-ICR mass spectral linewidths.

    Science.gov (United States)

    Jiang, Ting; Chen, Yu; Mao, Lu; Marshall, Alan G; Xu, Wei

    2016-01-14

    It is known that the ion collision cross section (CCS) may be calculated from the linewidth of a Fourier transform ion cyclotron resonance (FT-ICR) mass spectral peak at elevated pressure (e.g., ∼10(-6) Torr). However, the high mass resolution of FT-ICR is sacrificed in those experiments due to high buffer gas pressure. In this study, we describe a linewidth correction method to eliminate the windowing-induced peak broadening effect. Together with the energetic ion-neutral collision model previously developed by our group, this method enables the extraction of CCSs of biomolecules from high-resolution FT-ICR mass spectral linewidths, obtained at a typical operating buffer gas pressure of modern FT-ICR instruments (∼10(-10) Torr). CCS values of peptides including MRFA, angiotensin I, and bradykinin measured by the proposed method agree well with ion mobility measurements, and the unfolding of protein ions (ubiquitin) at higher charge states is also observed. PMID:26314765

  2. Label-free Raman mapping of surface distribution of protein a and IgG biomolecules.

    Science.gov (United States)

    Combs, Zachary A; Chang, Sehoon; Clark, Tolecia; Singamaneni, Srikanth; Anderson, Kyle D; Tsukruk, Vladimir V

    2011-03-15

    We have demonstrated a nanoengineered substrate composed of micropatterned silver nanoparticles to be used for the label-free mapping of adsorbed biomolecules. We utilized surface-enhanced Raman scattering (SERS) phenomenon to monitor the known bioanalytes, protein A and human immunoglobulin G (IgG). The SERS substrate was composed of a poly(alylamine hydrochloride) (PAH)/poly(styrenesulfonate) (PSS) layer-by-layer (LbL) nanocoating micropatterned with silver nanoparticles confined to microscopic stripes. Selective adsorption of biomacromolecules is facilitated by the amine-terminated LbL nanocoating, which prevents the surface adsorption of positively charged protein A across the surface except on the patterned regions containing negatively charged silver nanoparticles. Furthermore, adsorption of IgG on predetermined regions is facilitated by the selective binding of the Fc region of IgG to protein A. This label-free SERS approach provides accurate, selective, and fast detection of protein A and IgG solutions with a nanomolar concentration, down to below 1 nM for IgG in solution. This method could also be utilized for the facile detection of proteins in field conditions as well as in clinical, forensic, industrial, and environmental laboratories. PMID:21294559

  3. 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.

  4. A Universal Method for Fishing Target Proteins from Mixtures of Biomolecules using Isothermal Titration Calorimetry

    International Nuclear Information System (INIS)

    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.

  5. AFNMR: automated fragmentation quantum mechanical calculation of NMR chemical shifts for biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Swails, Jason [Rutgers University, Department of Chemistry and Chemical Biology and BioMaPS Institute (United States); Zhu, Tong; He, Xiao, E-mail: xiaohe@phy.ecnu.edu.cn [East China Normal University, State Key Laboratory of Precision Spectroscopy, Institute of Theoretical and Computational Science (China); Case, David A., E-mail: case@biomaps.rutgers.edu [Rutgers University, Department of Chemistry and Chemical Biology and BioMaPS Institute (United States)

    2015-10-15

    We evaluate the performance of the automated fragmentation quantum mechanics/molecular mechanics approach (AF-QM/MM) on the calculation of protein and nucleic acid NMR chemical shifts. The AF-QM/MM approach models solvent effects implicitly through a set of surface charges computed using the Poisson–Boltzmann equation, and it can also be combined with an explicit solvent model through the placement of water molecules in the first solvation shell around the solute; the latter substantially improves the accuracy of chemical shift prediction of protons involved in hydrogen bonding with solvent. We also compare the performance of AF-QM/MM on proteins and nucleic acids with two leading empirical chemical shift prediction programs SHIFTS and SHIFTX2. Although the empirical programs outperform AF-QM/MM in predicting chemical shifts, the differences are in some cases small, and the latter can be applied to chemical shifts on biomolecules which are outside the training set employed by the empirical programs, such as structures containing ligands, metal centers, and non-standard residues. The AF-QM/MM described here is implemented in version 5 of the SHIFTS software, and is fully automated, so that only a structure in PDB format is required as input.

  6. 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.

  7. EFFECT OF CARBOFURAN ON THE FORMATION OF SOME BIOMOLECULES IN BRINJAL (SOLANUM MELONGENA L. LEAF

    Directory of Open Access Journals (Sweden)

    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.

  8. Thermoresponsive anionic copolymer brushes containing strong acid moieties for effective separation of basic biomolecules and proteins.

    Science.gov (United States)

    Nagase, Kenichi; Kobayashi, Jun; Kikuchi, Akihiko; Akiyama, Yoshikatsu; Kanazawa, Hideko; Okano, Teruo

    2014-10-13

    A thermoresponsive copolymer brush possessing the sulfonic acid group, poly(N-isopropylacrylamide (IPAAm)-co-2-acrylamido-2-methylpropanesulfonic acid (AMPS)-co-tert-butylacrylamide (tBAAm)), was grafted onto the surface of silica beads through surface-initiated atom transfer radical polymerization. Prepared copolymer and copolymer brushes on silica beads were characterized by observing the phase transition profile, CHNS elemental analysis, X-ray photoelectron spectroscopy, and gel permeation chromatography. The phase transition profile indicated that an appropriate AMPS composition for enabling thermally modulated property changes is 5 mol %, while excessive amounts of sulfonic acid groups prevented copolymer phase transition. Chromatographic elutions of catecholamine derivatives and basic proteins were observed, using the prepared copolymer brush-modified beads as chromatographic matrices, and the results suggest that the beads interact with these analytes through relatively strong electrostatic interactions. Thus, poly(IPAAm-co-AMPS-co-tBAAm) brush-modified beads will be useful for effective thermoresponsive chromatography matrices that separate basic biomolecules through strong electrostatic interactions. PMID:25220634

  9. N-acetyl-l-histidine, a Prominent Biomolecule in Brain and Eye of Poikilothermic Vertebrates

    Science.gov (United States)

    Baslow, Morris H.; Guilfoyle, David N.

    2015-01-01

    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. PMID:25919898

  10. 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.

  11. Prototype sphere-on-sphere silica particles for the separation of large biomolecules.

    Science.gov (United States)

    Fekete, Szabolcs; Rodriguez-Aller, Marta; Cusumano, Alessandra; Hayes, Richard; Zhang, Haifei; Edge, Tony; Veuthey, Jean-Luc; Guillarme, Davy

    2016-01-29

    The goal of this study was to evaluate the possibilities offered by a prototype HPLC column packed with ∼2.5μm narrow size distribution sphere-on-sphere (SOS) silica particles bonded with C4 alkyl chains, for the analytical characterization of large biomolecules. The kinetic performance of this material was evaluated in both isocratic and gradient modes using various model analytes. The data were compared to those obtained on other widepore state-of-the-art fully core-shell and fully porous materials commonly employed to separate proteins moreover to a reference 5μm wide pore material that is still often used in QC labs. In isocratic mode, minimum reduced plate height values of hmin=2.6, 3.3 and 3.3 were observed on butylparaben, decapeptide and glucagon, respectively. In gradient elution mode, the SOS column performs very high efficiency when working with fast gradients. This prototype column was also comparable (and sometimes superior) to other widepore stationary phases, whatever the gradient time and flow rate, when analyzing the largest model protein, namely BSA. These benefits may be attributed to the SOS particle morphology, minimizing the intra-particle mass transfer resistance. Finally, the SOS column was also applied for the analytical characterization of commercial monoclonal antibody (mAb) and antibody-drug conjugate (ADC) samples. With these classes of proteins, the performance of SOS column was similar to the best widepore stationary phases available on the market. PMID:26755414

  12. 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. PMID:27563852

  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

    2014-01-01

    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. Excitation and ionic fragmentation of gas-phase biomolecules using electrons and synchrotron radiation

    Science.gov (United States)

    de Souza, G. G. B.; Coutinho, L. H.; Nunez, C.; Bernini, R.; Castilho, R. B.; Lago, A. F.

    2007-11-01

    An experimental study of the electronic excitation and ionic dissociation of two important classes of biomolecules-natural products (biogenic volatile organic compounds, VOCs, and volatile components of essential oils) and DNA and RNA constituents (aminoacids and bases) is here exemplified with recent results on the fragmentation of thymine and isoprene as induced by synchrotron radiation and fast electrons. Fragmentation of the thymine molecule was seen to dramatically increase as the photon energy increased from 21 to 300 eV and 450 eV. At the highest photon energy, simply and doubly charged N and O atoms were observed. The parent ion (m/z = 126) could be observed at all photon energies. The fragmentation pattern observed in the 1.0 keV electron impact mass spectrum of thymine resembled more closely the fragmentation observed with 21 eV photons. In isoprene, the dominant fragments observed at 21 eV and 310 eV photon energy as well as in the 1.0 keV electron impact mass spectrum were C5H7+(m/z = 67), C4H5+(m/z = 53), C3H3+(m/z = 39) and C2H3+(m/z = 27). Previously unreported fragments, namely H+, C+, CH+, CH2+, and CH3+ were observed at the high photon energies and at the electron impact mass spectrum.

  15. 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. PMID:27199301

  16. 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.

  17. Biomolecule-Mineral Interactions in the Geochemical Environment on Early Earth and in the Human Body

    Science.gov (United States)

    Sahai, N.

    2011-12-01

    We worked on four projects consistent with the broad goals of the grant to investigate (i) the potential impacts of mineral surface chemistry and particle size on the stability and viability of cell membranes, bacteria and human cells and (ii) the influence of biomolecules on mineral nucleation and growth. The projects are of relevance to the origin and early evolution of life, biomineralization, medical mineralogy, and environmental biogeochemistry. The freedom enabled by the five-year grant to explore high-risk scientific areas, and the resulting high impact outcomes, cannot be overstated. We developed an almost entirely new field of Medical Mineralogyy and extended our concepts and knowledge-base to the potential roles of mineral surfaces in the evolution of protocells and the earliest cells. These exciting connections to medical mineralogy, and to the origin and evolution of life on early Earth are fascinating topics to the general public and even to other scientists, especially when the links to mineralogy and geochemistry are highlighted. In brief, we examined the stability of lipid bilayers representing model protocell membranes comprised of phospholipid bilayers with mineral surfaces. We found that the stability of lipid bilayers depends on mineral surface charge and increases as silica glass ~ quartz newspapers and television at the International Mineralogical Association's Annual Meeting.

  18. 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.

  19. Experimental detection of long-distance interactions between biomolecules through their diffusion behavior: Numerical study

    Science.gov (United States)

    Nardecchia, Ilaria; Spinelli, Lionel; Preto, Jordane; Gori, Matteo; Floriani, Elena; Jaeger, Sebastien; Ferrier, Pierre; Pettini, Marco

    2014-08-01

    The dynamical properties and diffusive behavior of a collection of mutually interacting particles are numerically investigated for two types of long-range interparticle interactions: Coulomb-electrostatic and dipole-electrodynamic. It is shown that when the particles are uniformly distributed throughout the accessible space, the self-diffusion coefficient is always lowered by the considered interparticle interactions, irrespective of their attractive or repulsive character. This fact is also confirmed by a simple model to compute the correction to the Brownian diffusion coefficient due to the interactions among the particles. These interactions are also responsible for the onset of dynamical chaos and an associated chaotic diffusion which still follows an Einstein-Fick-like law for the mean-square displacement as a function of time. Transitional phenomena are observed for Coulomb-electrostatic (repulsive) and dipole-electrodynamic (attractive) interactions considered both separately and in competition. The outcomes reported in this paper clearly indicate a feasible experimental method to probe the activation of resonant electrodynamic interactions among biomolecules.

  20. 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.

  1. 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

    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......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......). The highest protein and fatty acid content were found in SB's, up to 12.7 ± 0.3 and 2.5 ± 0.1 g L-1, respectively. Long chain n-3 polyunsaturated fatty acids represented up to 44.5% of total fatty acids. In all samples, leucine and glutamic acid/glutamine were the dominating amino acids while calcium...

  2. 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.

  3. Aequorin as a bioluminescent indicator for use in the determination of biomolecules in single cells. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Sylvia Daunert

    2000-02-17

    During this funding period, the laboratories of Drs. Anderson and Daunert have performed a considerable amount of work toward addressing the issues associated with small volume analysis necessary for single cell studies. In that respect, their research has been focused on (1) developing new assays that can be miniaturized and are suitable for small volume and single cell analysis; (2) fabricating pL-vials that simulate the volume of single cells and setting up instrumentation capable of low-volume detection; (3) developing reproducible and reliable microinjection techniques; (4) developing methods of analysis for biomolecules in the pL-vials and employing these assays in the detection of biomolecules in single cells. The accomplishments attained in all these areas are described below. A total of 24 publications and 35 presentations have resulted from this work.

  4. 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,…

  5. DNA-based Nanoconstructs for the Detection of Ions and Biomolecules with Related Raman/SERS Signature Studies

    Science.gov (United States)

    Brenneman, Kimber L.

    The utilization of DNA aptamers and semiconductor quantum dots (QDs) for the detection of ions and biomolecules was investigated. In recent years, there have been many studies based on the use of DNA and RNA aptamers, which are single stranded oligonucleotides capable of binding to biomolecules, other molecules, and ions. In many of these cases, the conformational changes of these DNA and RNA aptamers are suitable to use fluorescence resonant energy transfer (FRET) or nanometal surface energy transfer (NSET) techniques to detect such analytes. Coupled with this growth in such uses of aptamers, there has been an expanded use of semiconductor quantum dots as brighter, longer-lasting alternatives to fluorescent dyes in labeling and detection techniques of interest in biomedicine and environmental monitoring. Thrombin binding aptamer (TBA) and a zinc aptamer were used to detect mercury, lead, zinc, and cadmium. These probes were tested in a liquid assay as well as on a filter paper coupon. Biomolecules were also studied and detected using surface-enhanced Raman spectroscopy (SERS), including DNA aptamers and C-reactive protein (CRP). Raman spectroscopy is a useful tool for sensor development, label-free detection, and has the potential for remote sensing. Raman spectra provide information on the vibrational modes or phonons, between and within molecules. Therefore, unique spectral fingerprints for single molecules can be obtained. SERS is accomplished through the use of substrates with nanometer scale geometries made of metals with many free electrons, such as silver, gold, or copper. In this research silver SERS substrates were used to study the SERS signature of biomolecules that typically produce very weak Raman signals.

  6. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... before cancer How you respond to treatment Seeking Information About Your Prognosis Is a Personal Decision When ... Twitter Instagram YouTube Google+ LinkedIn GovDelivery RSS CONTACT INFORMATION Contact Us LiveHelp Online Chat MORE INFORMATION About ...

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

    OpenAIRE

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

    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 consider...

  8. Redox Reactivity of Cerium Oxide Nanoparticles Induces the Formation of Disulfide Bridges in Thiol-Containing Biomolecules.

    Science.gov (United States)

    Rollin-Genetet, Françoise; Seidel, Caroline; Artells, Ester; Auffan, Mélanie; Thiéry, Alain; Vidaud, Claude

    2015-12-21

    The redox state of disulfide bonds is implicated in many redox control systems, such as the cysteine-cystine couple. Among proteins, ubiquitous cysteine-rich metallothioneins possess thiolate metal binding groups susceptible to metal exchange in detoxification processes. CeO2 NPs are commonly used in various industrial applications due to their redox properties. These redox properties that enable dual oxidation states (Ce(IV)/Ce(III)) to exist at their surface may act as oxidants for biomolecules. The interaction among metallothioneins, cysteine, and CeO2 NPs was investigated through various biophysical approaches to shed light on the potential effects of the Ce(4+)/Ce(3+) redox system on the thiol groups of these biomolecules. The possible reaction mechanisms include the formation of a disulfide bridge/Ce(III) complex resulting from the interaction between Ce(IV) and the thiol groups, leading to metal unloading from the MTs, depending on their metal content and cluster type. The formation of stable Ce(3+) disulfide complexes has been demonstrated via their fluorescence properties. This work provides the first evidence of thiol concentration-dependent catalytic oxidation mechanisms between pristine CeO2 NPs and thiol-containing biomolecules. PMID:26566067

  9. Sensitivity improvement of an electrical sensor achieved by control of biomolecules based on the negative dielectrophoretic force.

    Science.gov (United States)

    Kim, Hye Jin; Kim, Jinsik; Yoo, Yong Kyoung; Lee, Jeong Hoon; Park, Jung Ho; Hwang, Kyo Seon

    2016-11-15

    Effective control of nano-scale biomolecules can enhance the sensitivity and limit of detection of an interdigitated microelectrode (IME) sensor. Manipulation of the biomolecules by dielectrophoresis (DEP), especially the negative DEP (nDEP) force, so that they are trapped between electrodes (sensing regions) was predicted to increase the binding efficiency of the antibody and target molecules, leading to a more effective reaction. To prove this concept, amyloid beta 42 (Aβ42) and prostate specific antigen (PSA) protein were respectively trapped between the sensing region owing to the nDEP force under 5V and 0.05V, which was verified with COMSOL simulation. Using the simulation value, the resistance change (ΔR/Rb) of the IME sensor from the specific antibody-antigen reaction of the two biomolecules and the change in fluorescence intensity were compared in the reference (pDEP) and nDEP conditions. The ΔR/Rb value improved by about 2-fold and 1.66-fold with nDEP compared to the reference condition with various protein concentrations, and these increases were confirmed with fluorescence imaging. Overall, nDEP enhanced the detection sensitivity for Aβ42 and PSA by 128% and 258%, respectively, and the limit of detection improved by up to 2-orders of magnitude. These results prove that DEP can improve the biosensor's performance. PMID:27449966

  10. Russian oil workers seek employment abroad

    International Nuclear Information System (INIS)

    This paper reports that American oil workers discouraged by bleak employment opportunities in the U.S. petroleum industry face increasing competition abroad from Russians seeking a living wage. Moscow's Zagrantrud (Foreign Labor) firm believes millions of Russian skilled and unskilled workers in many occupations will try to find jobs in other countries. The Russian enterprise says it is selecting a group of construction workers to build a refinery in Columbia. Kuwait also wants Russian construction personnel. Russia is especially eager to find overseas work for petroleum industry workers who have lost their jobs in Viet Nam and Cuba. The number of specialists from the former U.S.S.R. in Cuba, many of them engaged in oil exploration and production or pipeline and refinery construction, has fallen from several thousand 2 years ago to 250 at present as Moscow's relations with Havana cooled

  11. 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...

  12. A Ruthenium(II) Complex Supported by Trithiacyclononane and Aromatic Diimine Ligand as Luminescent Switch-On Probe for Biomolecule Detection and Protein Staining

    Science.gov (United States)

    Wong, Chun-Yuen; Chung, Lai-Hon; Lin, Sheng; Chan, Daniel Shiu-Hin; Ma, Dik-Lung

    2014-01-01

    A new ruthenium(II) complex has been developed for detection of biomolecules. This complex is highly selective for histidine over other amino acids and has been applied to protein staining in an SDS-PAGE gel. PMID:25409703

  13. Theoretical foundation and experimental proof of the accumulating transfer of tritium from water into DNA and other biomolecules in vitro and in vivo

    International Nuclear Information System (INIS)

    Theoretical foundation and experimental proof of the accumulating transfer of tritium from water into DNA and other biomolecules were presented using the data of experiments on fish sperm DNA and piglet's liver (in vitro tests) and maize and barley (in vivo tests). Heisenberg's uncertainty principle, which describes a fundamental property of matter, predicts the light hydrogen isotope to prefer strong hydrogen bridge positions (with large local uncertainty). In contrast, the heavy hydrogen isotope tritium originally localized in water, should finally be found in the exchangeable hydrogen bridge positions of proteins, carbohydrates and nucleotides which are definitely less strong than those of water. Fractionation factor of tritium and protonium measured between water and DNA as well as the mixture of biomolecules of liver confirm this conclusion and show tritium accumulation biomolecules. Furthermore, the elevated rate of natural increase in tritium concentration in tissue solids of growing maize and barley confirm the accumulating tritium transfer from water to biomolecules taking place in vivo

  14. Development of methods for the purification of 67Ga and 68Ga for biomolecules labeling

    International Nuclear Information System (INIS)

    For more than fifty years, the long-lived 68Ge/68Ga generators have been in development, obtaining 68Ga without the need of having in house cyclotron, which is a considerable convenience for PET centers that have no nearby cyclotrons. 68Ga decays 89% by positron emission and low photon emission (1077 keV) and the physical half life of 67.7 minutes is compatible with the pharmacokinetics of low biomolecular weight substances like peptides and antibody fragments. Moreover, its established metallic chemistry allows it to be stably bound to the carrier peptide sequence via a suitable bifunctional chelator, such as DOTA. All these reasons together with the technology of PET/CT allowed advances in molecular imaging, in particular in the diagnosis of neuroendocrine diseases. However, the eluate from the commercial 68Ge/68Ga generators still contains high levels of long lived 68Ge, besides other metallic impurities, which competes with 68Ga with a consequent reduction of the labeling yield of biomolecules, such as Fe3+ and Zn2+. Thus, the lower the amount of impurities in the eluate, the competition between the radiolabeled and unlabeled peptide by the receptor will be smaller and the quality of imaging will be better, a subsequent purification step is needed after the generator elution. The aim of this work is to evaluate different purifications methods of 68Ga to label biomolecules, with emphasis on the study of the chemical impurities contained in the eluate and to develop a new purification method. Several purification methods were studied. Many cationic resin were tested simulating the commercial process. 68Ga is adsorbed in cationic resin, which is not commercial available and eluted in acid/acetone solution. The use of minor particles of cationic resin AG50W-X4 (200-400 mesh) showed the best results. An innovate method was the extraction chromatography, which is based on the absorption of diisopropyl ether in XAD 16 and 68Ga recovery in deionized water. Although the

  15. Submicron-resolution photoacoustic microscopy of endogenous light-absorbing biomolecules

    Science.gov (United States)

    Zhang, Chi

    Photoacoustic imaging in biomedicine has the unique advantage of probing endogenous light absorbers at various length scales with a 100% relative sensitivity. Among the several modalities of photoacoustic imaging, optical-resolution photoacoustic microscopy (OR-PAM) can achieve high spatial resolution, on the order of optical wavelength, at detection. We achieved 220 nm lateral resolution in transmission mode, 0.43 microm lateral resolution in reflection mode, 7.6 microm axial resolution in normal tissue, and 5.8 microm axial resolution with silicone oil immersion/injection. The achieved lateral resolution and axial resolution were the finest reported at the time. With high-resolution in 3D, PAM was demonstrated to resolve cellular and subcellular structures in vivo, such as red blood cells and melanosomes in melanoma cells. Compared with previous PAM systems, our high-resolution PAM could resolve capillaries in mouse ears more clearly. As an example application, we demonstrated intracellular temperature imaging, assisted by fluorescence signal detection, with sub-degree temperature resolution and sub-micron lateral resolution. The second part of this dissertation describes the exploration of endogenous light-absorbing biomolecules for PAM. We demonstrated cytochromes and myoglobin as new absorption contrasts for PAM and identified the corresponding optimal wavelengths for imaging. Fixed fibroblasts on slides and mouse ear sections were imaged by PAM at 422 nm and 250 nm wavelengths to reveal cytoplasms and nuclei, respectively, as confirmed by standard hematoxylin and eosin (H&E) histology. By imaging a blood-perfused mouse heart at 532 nm down to 150 microm in depth, we derived the myocardial sheet thickness and the cleavage height from an undehydrated heart for the first time. The findings promote PAM at new wavelengths and open up new possibilities for characterizing biological tissue. Of particular interest, dual-wavelength PAM around 250 nm and 420 nm

  16. Heavy metal induced biomolecule and genotoxic changes in earthworm Eisenia fetida

    Directory of Open Access Journals (Sweden)

    G. Muthukaruppan

    2015-09-01

    Full Text Available A vibrational [Fourier transform infrared (FTIR] spectroscopic method was used for the structural and compositional analysis of earthworm Eisenia fetida by monitoring of metal binding and further transformations in live cells. The FTIR analyses for metals taken up by the E. fetida will be useful for analyzing the impact of the heavy metal stress on the worm metabolism. The epigeic earthworm E. fetida were exposed to 100 %, 75 %, 50 %, 30 %, 25 %, 15 % and 5 % of dried automobile service station waste mud. All the earthworms exposed in the 100 %, 75 % and 50 % concentrations didn’t survived within 10days. Further experiments were conducted with 25 %, 15 % and 5 % concentration of wastes. Each concentration level was tested with three replicates using 10 animals and the metabolic response after exposure to the heavy metal containing service station waste mud was assessed by FTIR. Furthermore we also emphasized that DNA damage was confirmed with the use of other biomarker like comet assay. The peaks at 1045, 1080, 1236 cm−1 and 1650 cm−1 represented the overall susceptibility of nucleotides, phospholipids, DNA and RNA. Nucleic acids and proteins were modified due to heavy metal accumulation. In flow-through, single cell gel electrophoresis revealed the degradation nuclear DNA. Heavy metals accumulation in the worms was measured and it was found that lead, zinc and copper accumulation increased in the treatment group. Without the use of biomarkers for identifying ecological risks of land contamination, traditional assessment would be difficult to interpret. This new FTIR based biomolecules study revealed a clear molecule shift in the exposed worms, due to heavy metal accumulation.

  17. High-Precision Dispensing of Nanoliter Biofluids on Glass Pedestal Arrays for Ultrasensitive Biomolecule Detection.

    Science.gov (United States)

    Chen, Xiaoxiao; Liu, Yang; Xu, QianFeng; Zhu, Jing; Poget, Sébastien F; Lyons, Alan M

    2016-05-01

    Precise dispensing of nanoliter droplets is necessary for the development of sensitive and accurate assays, especially when the availability of the source solution is limited. Conventional approaches are limited by imprecise positioning, large shear forces, surface tension effects, and high costs. To address the need for precise and economical dispensing of nanoliter volumes, we developed a new approach where the dispensed volume is dependent on the size and shape of defined surface features, thus freeing the dispensing process from pumps and fine-gauge needles requiring accurate positioning. The surface we fabricated, called a nanoliter droplet virtual well microplate (nVWP), achieves high-precision dispensing (better than ±0.5 nL or ±1.6% at 32 nL) of 20-40 nL droplets using a small source drop (3-10 μL) on isolated hydrophilic glass pedestals (500 μm on a side) bonded to arrays of polydimethylsiloxane conical posts. The sharp 90° edge of the glass pedestal pins the solid-liquid-vapor triple contact line (TCL), averting the wetting of the glass sidewalls while the fluid is prevented from receding from the edge. This edge creates a sufficiently large energy barrier such that microliter water droplets can be poised on the glass pedestals, exhibiting contact angles greater >150°. This approach relieves the stringent mechanical alignment tolerances required for conventional dispensing techniques, shifting the control of dispensed volume to the area circumscribed by the glass edge. The effects of glass surface chemistry and dispense velocity on droplet volume were studied using optical microscopy and high-speed video. Functionalization of the glass pedestal surface enabled the selective adsorption of specific peptides and proteins from synthetic and natural biomolecule mixtures, such as venom. We further demonstrate how the nVWP dispensing platform can be used for a variety of assays, including sensitive detection of proteins and peptides by fluorescence

  18. Fullerene hollow microspheres prepared by bubble-templates as sensitive and selective electrocatalytic sensor for biomolecules.

    Science.gov (United States)

    Wei, Lang; Lei, Yilong; Fu, Hongbing; Yao, Jiannian

    2012-03-01

    We developed an electrocatalytic sensor based on C(60) hollow microspheres for highly sensitive and selective detection of dopamine (DA) in the presence of ascorbic acid (AA), and uric acid (UA) in the presence of l-cysteine (RSH). The hollow microspheres of C(60) with a diameter controllable in the range of 0.5 to 1.5 μm and a thickness of 200 nm are synthesized by a high-temperature reprecipitation method with the assistance of alcohol bubbles. The superhydrophobicity of C(60) hollow microspheres makes them capable of forming a compact thin film at air/water interface, which can be readily transferred on the surface of gold or glassy carbon electrodes. This porous C(60) film made from C(60) hollow microspheres shows a specific surface area as high as 107 m(2) g(-1). In order to obtain a conducting film, the C(60)-modified electrode is pretreated by scanning the potential range from 0.0 to -1.5 V in 1 M KOH followed by potential cycling between 550 to -50 mV in a pH 7.2 phosphate buffer solution. On the basis of XPS and IR measurements, we found that surface oxides, such as -OH and C═O groups, are introduced on the surfaces of the conducting C(60) film. This, combined with the porosity that enhances the adsorption activity of C(60)-modified electrodes, enable the electrocatalytic analysis of target biomolecules with detection limit as low as 0.1 nM for DA in the presence of AA, and 1 μM for UA in the presence of RSH. PMID:22391457

  19. Cytoplasmic electric fields and electroosmosis: possible solution for the paradoxes of the intracellular transport of biomolecules.

    Directory of Open Access Journals (Sweden)

    Victor P Andreev

    Full Text Available The objective of the paper is to show that electroosmotic flow might play an important role in the intracellular transport of biomolecules. The paper presents two mathematical models describing the role of electroosmosis in the transport of the negatively charged messenger proteins to the negatively charged nucleus and in the recovery of the fluorescence after photobleaching. The parameters of the models were derived from the extensive review of the literature data. Computer simulations were performed within the COMSOL 4.2a software environment. The first model demonstrated that the presence of electroosmosis might intensify the flux of messenger proteins to the nucleus and allow the efficient transport of the negatively charged phosphorylated messenger proteins against the electrostatic repulsion of the negatively charged nucleus. The second model revealed that the presence of the electroosmotic flow made the time of fluorescence recovery dependent on the position of the bleaching spot relative to cellular membrane. The magnitude of the electroosmotic flow effect was shown to be quite substantial, i.e. increasing the flux of the messengers onto the nucleus up to 4-fold relative to pure diffusion and resulting in the up to 3-fold change in the values of fluorescence recovery time, and therefore the apparent diffusion coefficient determined from the fluorescence recovery after photobleaching experiments. Based on the results of the modeling and on the universal nature of the electroosmotic flow, the potential wider implications of electroosmotic flow in the intracellular and extracellular biological processes are discussed. Both models are available for download at ModelDB.

  20. Alternating current electrohydrodynamics in microsystems: Pushing biomolecules and cells around on surfaces.

    Science.gov (United States)

    Vaidyanathan, Ramanathan; Dey, Shuvashis; Carrascosa, Laura G; Shiddiky, Muhammad J A; Trau, Matt

    2015-11-01

    Electrohydrodynamics (EHD) deals with the fluid motion induced by an electric field. This phenomenon originally developed in physical science, and engineering is currently experiencing a renaissance in microfluidics. Investigations by Taylor on Gilbert's theory proposed in 1600 have evolved to include multiple contributions including the promising effects arising from electric field interactions with cells and particles to influence their behaviour on electrode surfaces. Theoretical modelling of electric fields in microsystems and the ability to determine shear forces have certainly reached an advanced state. The ability to deftly manipulate microscopic fluid flow in bulk fluid and at solid/liquid interfaces has enabled the controlled assembly, coagulation, or removal of microstructures, nanostructures, cells, and molecules on surfaces. Furthermore, the ability of electrohydrodynamics to generate fluid flow using surface shear forces generated within nanometers from the surface and their application in bioassays has led to recent advancements in biomolecule, vesicle and cellular detection across different length scales. With the integration of Alternating Current Electrohydrodynamics (AC-EHD) in cellular and molecular assays proving to be highly fruitful, challenges still remain with respect to understanding the discrepancies between each of the associated ac-induced fluid flow phenomena, extending their utility towards clinical diagnostic development, and utilising them in tandem as a standard tool for disease monitoring. In this regard, this article will review the history of electrohydrodynamics, followed by some of the recent developments in the field including a new dimension of electrohydrodynamics that deals with the utilization of surface shear forces for the manipulation of biological cells or molecules on electrode surfaces. Recent advances and challenges in the use of electrohydrodynamic forces such as dielectrophoresis and ac electrosmosis for the

  1. Water soluble polymer films for intravascular drug delivery of antithrombotic biomolecules.

    Science.gov (United States)

    Scott, Rebecca A; Park, Kinam; Panitch, Alyssa

    2013-05-01

    Over the past 10 years, the number of percutaneous coronary intervention (PCI) procedures performed in the United States has increased by 33%; however, restenosis, which inhibits complete functional recovery of the vessel wall, remains a complication of this procedure. To traverse the complications associated with PCI, the investigation of therapeutic delivery has become an integral topic in modern research. One such therapeutic, a mimic of the proteoglycan decorin, termed DS-SILY, can mask exposed collagen and thereby effectively decrease platelet activation, has recently been developed by our lab. Drawing inspiration from coating technologies developed by the pharmaceutical industry, a fast-dissolving polymer film has been developed to deliver active therapeutic agents from a balloon catheter during PCI. This research investigates the release of DS-SILY from fast-dissolving polymer films composed of poly(vinyl alcohol) (PVA) and poly(ethylene glycol) (PEG). Thin, uniform polymer films were produced via spin coating technique. The dissolution speed of the polymer films was found to be dependent on the concentration of polymer solution, where at least 65% of the films were shown to dissolve into nanometer sized polymer fragments within 2 min. DS-SILY, up to 6.26 μg/cm(2), was loaded into the films and functional release of the mimic was demonstrated by its successful binding to collagen upon release. Furthermore, DS-SILY released from films resulted in increased platelet inhibition. These results indicate that use of fast-dissolving polymer films allow for the successful release of biomolecules and further investigation of their use for localized drug delivery during PCI procedures is warranted. PMID:23262161

  2. Similarities between several major extinctions and preservation of life - biomolecules to geomolecules: an interdisciplinary approach

    Science.gov (United States)

    Grice, Kliti; Melendez, Ines; Tulipani, Svenja

    2015-04-01

    coexistence of biomolecules and geomolecules in the same sample, previously assumed unfeasible. The coexistence of steroids in a diagenetic continuum, ranging from stenols to triaromatic steroids, is attributed to microbially mediated eogenetic processes. Under exceptional conditions concretions preserve biomolecules at extraordinary levels, providing a new opportunity to study the distributions of biomolecules in deep time and thereby improving our understanding of the evolution of life where fossils are rarely preserved. References [1] Grice K., Cao C., Love G.D., Bottcher M.E., Twitchett R,, Grosjean E., Summons R.E., Turgeon S., Dunning W.J. & Jin Y., 2005. Photic zone euxinia during the Permian-Triassic superanoxic event. Science. 307, 706-709. [2] Jaraula C.M.B, Grice K., Twitchett R.,J., Böttcher M.E., Le Metayer P., Dastidar A.G. & Opazo L.F., 2013. Elevated pCO2 leading to Late triassic extinction, persistent photic zone euxinia, and rising sea levels. Geology 41, 955-958. [3] Tulipani S., Grice K., Greenwood P.F, Haines P., Sauer P., Schimmelmann A., Summons R.E., Foster C.B., Böttcher M.E., Playton, T. & Schwark L., 2014a. Changes in palaeoenvironmental conditions in Late Devonian Reef systems from the Canning Basin, WA: A biomarker and stable isotope approach. Gondwana Research, in press. [4] Melendez I., Grice K., Trinajstic K., Ladjavardi M., Thompson K. & Greenwood P.F., 2013a. Biomarkers reveal the role of photic zone euxinia in exceptional fossil preservation: An organic geochemical perspective. Geology 41, 123-126. [5] Melendez I., Grice K. & Schwark L., 2013b. Exceptional preservation of palaeozoic steroids in a diagenetic continuum. Nature Scientific Reports. 3. [6] Grice K., Lu H., Atahan P., Hallmann, C., Asif M., Greenwood P.F., Tulipani S., Maslen E., Williford W.H. & Dodson J. 2009. New insights into the origin of perlyene in geological samples Geochimica et Cosmochimica Acta, 73, 6531-6543. [7] Tulipani S., Grice K., Greenwood P.F., Schwark L

  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. 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.

  7. Sensation seeking predicting growth in adolescent problem behaviors.

    Science.gov (United States)

    Byck, Gayle R; Swann, Gregory; Schalet, Benjamin; Bolland, John; Mustanski, Brian

    2015-06-01

    There is limited literature on the relationship between sensation seeking and adolescent risk behaviors, particularly among African Americans. We tested the association between psychometrically-derived subscales of the Zuckerman Sensation Seeking Scale and the intercepts and slopes of individual growth curves of conduct problems, sexual risk taking, and substance use from ages 13 to 18 years by sex. Boys and girls had different associations between sensation seeking and baseline levels and growth of risk behaviors. The Pleasure Seeking scale was associated with baseline levels of conduct problems in boys and girls, baseline substance use in boys, and growth in sexual risk taking and substance use by girls. Girls had the same pattern of associations with the Danger/Novelty scale as the Pleasure Seeking scale. Knowledge about the relationships between adolescent risk taking and sensation seeking can help in the targeted design of prevention and intervention programs for the understudied population of very low-income, African American adolescents. PMID:25112599

  8. 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.

  9. Brain mechanisms underlying sensation-seeking in humans

    OpenAIRE

    Norbury, A. E.

    2015-01-01

    Sensation-seeking is a personality trait concerned with motivation for intense and unusual sensory experiences, that has been identified as risk factor for a variety of psychopathologies with high social cost; in particular gambling and substance addictions. It has previously proved difficult to tease out neural mechanisms underlying sensation-seeking in humans, due to a lack of cognitive-behavioural paradigms probing sensation-seeking-like behaviour in the lab. The first aim of this thesis w...

  10. Price Competition in Markets with Consumer Variety Seeking

    OpenAIRE

    P. B. Seetharaman; Hai Che

    2009-01-01

    We investigate price competition between firms in markets characterized by consumer variety seeking. While previous research has addressed the effect of consumer inertia on prices, there exists no research on the effects of variety seeking on price competition. Our study fills this gap in the literature. Using a two-period duopoly framework as in Klemperer's analysis of inertial markets, we show that the noncooperative pricing equilibrium in a market with consumer variety seeking may be the s...

  11. Novelty seeking as a phenotypic marker of adolescent substance use

    OpenAIRE

    Cinnamon Bidwell, L; Knopik, Valerie S.; Janet Audrain-McGovern; Glynn, Tiffany R; Spillane, Nichea S.; Ray, Lara A.; Riggs, Nathaniel R.; Guillot, Casey R.; Pang, Raina D.; Leventhal, Adam M.

    2015-01-01

    © the authors, publisher and licensee Libertas Academica Limited. Trait novelty seeking has been consistently implicated in substance use, yet the origins and mechanisms of novelty seeking in substance use proneness are unclear. We aimed to characterize novelty seeking as a phenotypic marker of substance use proneness in adolescence, a critical period for drug use experimentation. To this end, we parsed novelty seeking’s two constituent subdimensions – exploratory excitability (drive for nove...

  12. Positioning and Pricing in a Variety Seeking Market

    OpenAIRE

    S. Sajeesh; Jagmohan S. Raju

    2010-01-01

    We study competitive positioning and pricing strategies in markets where consumers seek variety. Variety seeking behavior is modeled as a decrease in the willingness to pay for the product purchased on the previous purchase occasion. Using a three-stage Hotelling-type model, we show that the presence of variety seeking consumers reduces product differentiation offered in equilibrium, thereby explaining some otherwise counterintuitive findings in empirical research. We find that firms charge h...

  13. Using online media to encourage help-seeking for depression

    OpenAIRE

    Hui, Kar-yan, Alison; 許家欣

    2013-01-01

    Clinical depression has been prevalent in international health statistics but people are often found to be reluctant to seek help when they encounter depression. This thesis built and evaluated a mental health promotion campaign to encourage help-seeking through first forming a behavioral model to conceptualize the interplays of various factors in shaping one’s help-seeking intention and behavior for depression in Hong Kong. The thesis began with in-depth illness narrative qualitative in...

  14. Sex differences in sensation-seeking: a meta-analysis

    OpenAIRE

    Cross, Catharine Penelope; Cyrenne, De-Laine McGowan; Brown, Gillian Ruth

    2013-01-01

    Men score higher than women on measures of sensation-seeking, defined as a willingness to engage in novel or intense activities. This sex difference has been explained in terms of evolved psychological mechanisms or culturally transmitted social norms. We investigated whether sex differences in sensation-seeking have changed over recent years by conducting a meta-analysis of studies using Zuckerman's Sensation Seeking Scale, version V (SSS-V). We found that sex differences in total SSS-V scor...

  15. Predicting sensation seeking from dopamine genes: A candidate system approach

    OpenAIRE

    Derringer, Jaime; Robert F Krueger; Dick, Danielle M; Saccone, Scott; Grucza, Richard A.; Agrawal, Arpana; Lin, Peng; Almasy, Laura; Edenberg, Howard J.; Foroud, Tatiana; Nurnberger, John I.; Hesselbrock, Victor M.; Kramer, John R.; Kuperman, Samuel; Porjesz, Bernice

    2010-01-01

    Sensation seeking is a heritable personality trait that has been reliably linked to behavior disorders. The dopamine system has been hypothesized to contribute to individual differences in sensation seeking, and both experimental and observational studies in humans and non-human animals provide evidence for this relationship. We present here a candidate-system approach to genetic association analysis of sensation seeking, in which single nucleotide polymorphisms (SNPs) from a number of dopami...

  16. Sensation seeking, social attitudes and humor appreciation in Italy

    OpenAIRE

    Forabosco, Giovannantonio; Ruch, Willibald

    1994-01-01

    The present study examines the role of sensation seeking, conservatism, toughmindedness, sex, and age in appreciation of humor in Italian adults. A sample of 100 females and 48 males responded to Italian adaptations of the 3 WD humor test, Form V of the sensation seeking scale, and the C-Scale. Funniness of incongruity-resolution humor correlated positively with conservatism, female sex, and age, and negatively with all components of sensation seeking. Funniness of nonsense humor correlated p...

  17. Rent-seeking and quota regulation of a renewable resource

    OpenAIRE

    Bergland, Harald; Clark, Derek J.; Pedersen, Pål Andreas

    2001-01-01

    The paper deals with rent-seeking behaviour among agents competing for future shares of a common renewable natural resource. Rent-seeking might become profitable when the agents expect that the distribution of the natural resource in future periods will be dependent on the agents' extraction of the resource in the past, even though high exploitation might reduce the stock that future individual quotas will be based upon. Whether aggressive rent-seeking behaviour by one agent will encourage ot...

  18. INFORMATION SEEKING BEHAVIOUR OF STUDENTS IN THE INTERNET ERA

    OpenAIRE

    S. R. Girija

    2014-01-01

    Libraries develop their collections, facilities and services to meet the information needs of their patrons. However, in order to accomplish this task effectively, libraries must have a thorough understanding of the information needs and information seeking behavior of their users. This article examines the information - seeking behaviour of scholars in the Internet era. The articles focuses on how electronic information resources influence the information seeking process in s...

  19. Impulsivity and sensation seeking in alcohol abusing patients with schizophrenia

    OpenAIRE

    Alain Dervaux; Xavier Laqueille; Marie-Chantal Bourdel; Jean-Pierre Olié; Marie-Odile Krebs

    2010-01-01

    Objective: Some studies have found that high levels of impulsivity and sensation seeking, particularly disinhibition are associated with substance abuse in patients with schizophrenia, as in the general population. However, no study has assessed impulsivity and sensation seeking specifically in schizophrenia patients with alcohol abuse or dependence. Materials and methods: We compared impulsivity and sensation seeking in a group of schizophrenia patients (DSM-III-R criteria) with lifetime alc...

  20. EPA seeks preproposals for emerging technology program

    International Nuclear Information System (INIS)

    This portion of the Superfund Innovative Technology Evaluation (SITE) Program seeks to foster the further development of technologies that have successfully been tested at bench-scale and are now ready for pilot-scale testing prior to field or full-scale demonstration. The goal of the Emerging Technology Program is to ensure that a steady stream of permanent, cost-effective technologies will be ready for demonstration in the field, thereby increasing the number of viable alternatives available for use in Superfund site removal and remedial actions. The 1989 solicitation will emphasize technologies that can handle complex mixtures of hazardous organic and inorganic contaminants in sludges and soils by either in situ or on surface processes that separate, remove, destroy, detoxify, or stabilize the contaminates or provide for improved solids handling and pretreatment. Preproposals submitted in response to the RFP will be thoroughly reviewed and evaluated, andsuccessful prepropsers will be invited to submit competitive Cooperative Agreement Applications for funding consideration. EPA will cost-share in each of six to ten a maximum amount of $300,000 ($150,000 per year for two years)

  1. 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.

  2. Synthesis of mesoporous SiO{sub 2}-ZnO nanocapsules: encapsulation of small biomolecules for drugs and 'SiOZO-plex' for gene delivery

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Vijay Bhooshan [School of Engineering Sciences and Technology, University of Hyderabad (India); Annamanedi, Madhavi [School of Life Sciences, University of Hyderabad, Department of Animal Sciences (India); Prashad, Muvva Durga [University of Hyderabad, Centre for Nanoscience and Nanotechnology (India); Arunasree, Kalle M. [School of Life Sciences, University of Hyderabad, Department of Animal Sciences (India); Mastai, Yitzhak; Gedanken, Aharon, E-mail: gedanken@mail.biu.ac.il [Bar-Ilan University, Department of Chemistry, Institute for Nanotechnology and Advanced Materials (Israel); Paik, Pradip, E-mail: ppse@uohyd.ernet.in [School of Engineering Sciences and Technology, University of Hyderabad (India)

    2013-09-15

    This work presents a new synthesis of mesoporous SiO{sub 2}-ZnO composite nanocapsules with sizes of 90-150 nm and represents their applications in encapsulation of small biomolecules (fluorescent molecules, drugs, and DNA) for uses in medical biotechnology (e.g., drug and gene delivery) for the first time. The nanocapsule size and morphology have been confirmed through the HRSEM and HRTEM. The mesoporous structure of the novel materials has been confirmed through both BET and HRTEM, and the pore diameter observed to be ca. 2-8 nm with an average diameter of 5.1 nm. The BET surface area of mesoporous SiO{sub 2}-ZnO was found to be {approx}230 m{sup 2} g{sup -1}. Three different types of pores were detected through HRTEM: type-I, normal pores in silica matrix, pore with ZnO nanoparticles at the boundary (type-II) and type-III, the pores with tiny ZnO nanoparticles ({approx}5-7 nm) inside them. To demonstrate the biocompatibility and cell viability of the nanocapsules, normal and cancerous lymphocyte cells have been chosen and investigated in a systematic way. Fluorescent dye (Rhodamine 6G), anticancer drug e.g., Doxorubicin (DOX) were loaded in all types of pores, and EtBr-labeled DNA molecules were loaded efficiently into the mesopores of second and third types of the composite nanocapsules to manifest the characteristic of mesoporous, and to find out its loading efficacy. The release kinetics of Rhodamine 6G and DOX were studied. The results highlight the potential of novel functional mesoporous SiO{sub 2}-ZnO nanoparticles for using as the carrier of drugs and formation of 'SiOZO-plex', a complex of mesoporous SiO{sub 2}-ZnO with DNA for gene delivery applications.Graphical Abstract.

  3. Numerical simulation of mid-latitude ionospheric E-region based on SEEK and SEEK-2 observations

    OpenAIRE

    Takahashi, T.; Fukao, S.; Yamamoto, M.; Yokoyama, T.; Tanaka, M.

    2005-01-01

    Observational campaigns of the mid-latitude ionospheric E-region with sounding rockets and ground-based instruments were conducted in 1996 (SEEK) and 2002 (SEEK-2). Both of them were successfully conducted to bring important findings about the mid-latitude E-region and quasi-periodic (QP) VHF radar echoes. The observational results in the SEEK and the SEEK-2 are compared with numerical simulations and discussed in this paper. While sporadic-E (Es)-layers are actually formed by the ob...

  4. Numerical simulation of mid-latitude ionospheric E-region based on SEEK and SEEK-2 observations

    OpenAIRE

    Yokoyama, T.; Yamamoto, M.; Fukao, S.; Takahashi, T.; Tanaka, M.

    2005-01-01

    Observational campaigns of the mid-latitude ionospheric E-region with sounding rockets and ground-based instruments were conducted in 1996 (SEEK) and 2002 (SEEK-2). Both of them were successfully conducted to bring important findings about the mid-latitude E-region and quasi-periodic (QP) VHF radar echoes. The observational results in the SEEK and the SEEK-2 are compared with numerical simulations and discussed in this paper. While sporadic-E (Es)-layers are actually formed by the observed ne...

  5. Real-time monitoring and manipulation of single bio-molecules in free solution

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hung-Wing [Iowa State Univ., Ames, IA (United States)

    2005-01-01

    The observation and manipulation of single biomolecules allow their dynamic behaviors to be studied to provide insight into molecular genetics, biochip assembly, biosensor design, DNA biophysics. In a PDMS/glass microchannel, a nonuniform electroosmotic flow (EOF) was created. By using a scanning confocal fluorescence microscope and total internal-reflection fluorescence microscope (TIRFM), we demonstrated that negatively charged DNA molecules were focused by the nonuniform EOF into a thin layer at the glass surface. This phenomenon was applied to selectively detect target DNA molecules without requiring the separation of excessive probes and can be applied continuously to achieve high throughput. A variable-angle-TIRFM was constructed for imaging single DNA molecule dynamics at a solid/liquid interface. Implications we have are that the measured intensities cannot be used directly to determine the distances of molecules from the surface and the experimental counting results depict the distance-dependent dynamics of molecules near the surface; Molecules at low ionic strengths experience electrostatic repulsion at distances much further away from the surface than the calculated thickness of the electrical double layer. {delta}-DNA was employed as a nanoprobe for different functionalized surfaces to elucidate adsorption in chromatography. The 12-base unpaired ends of this DNA provide exposed purine and pyrimidine groups for adsorption. Patterns of self-assembled monolayers (SAMs) and patterns of metal oxides are generated. By recording the real-time dynamic motion of DNA molecules at the SAMs/aqueous interface, the various parameters governing the retention of an analyte during chromatographic separation can be studied. Even subtle differences among adsorptive forces can be revealed. Dynamic conformational changes of the prosthetic group, flavin adenine dinucleotide (FAD), in flavoprotein NADH peroxidase, in thioredoxin reductase, and in free solution were monitored

  6. 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.

  7. Mouse Monoclonal Antibodies for Liver Cancer Research | NCI Technology Transfer Center | TTC

    Science.gov (United States)

    The National Cancer Institute Laboratory of Molecular Biology seeks parties for collaborative research to co-develop and commercialize antibody drug/toxin conjugates as liver cancer therapy and diagnostics.

  8. 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

    of reproducibility. This technology can be used to circumvent the need for often expensive nano/microdispensing technologies. The ultimate size of the immobilised spots is defined by the focal area of the UV beam, which for a diffraction-limited beam can be less than 1 mm in diameter. LIMI has the added benefit...... 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...

  9. Fluorinated graphenes as advanced biosensors - effect of fluorine coverage on electron transfer properties and adsorption of biomolecules

    Science.gov (United States)

    Urbanová, Veronika; Karlický, František; Matěj, Adam; Šembera, Filip; Janoušek, Zbyněk; Perman, Jason A.; Ranc, Václav; Čépe, Klára; Michl, Josef; Otyepka, Michal; Zbořil, Radek

    2016-06-01

    Graphene derivatives are promising materials for the electrochemical sensing of diverse biomolecules and development of new biosensors owing to their improved electron transfer kinetics compared to pristine graphene. Here, we report complex electrochemical behavior and electrocatalytic performance of variously fluorinated graphene derivatives prepared by reaction of graphene with a nitrogen-fluorine mixture at 2 bars pressure. The fluorine content was simply controlled by varying the reaction time and temperature. The studies revealed that electron transfer kinetics and electrocatalytic activity of CFx strongly depend on the degree of fluorination. The versatility of fluorinated graphene as a biosensor platform was demonstrated by cyclic voltammetry for different biomolecules essential in physiological processes, i.e. NADH, ascorbic acid and dopamine. Importantly, the highest electrochemical performance, even higher than pristine graphene, was obtained for fluorinated graphene with the lowest fluorine content (CF0.084) due to its high conductivity and enhanced adsorption properties combining π-π stacking interaction with graphene regions with hydrogen-bonding interaction with fluorine atoms.Graphene derivatives are promising materials for the electrochemical sensing of diverse biomolecules and development of new biosensors owing to their improved electron transfer kinetics compared to pristine graphene. Here, we report complex electrochemical behavior and electrocatalytic performance of variously fluorinated graphene derivatives prepared by reaction of graphene with a nitrogen-fluorine mixture at 2 bars pressure. The fluorine content was simply controlled by varying the reaction time and temperature. The studies revealed that electron transfer kinetics and electrocatalytic activity of CFx strongly depend on the degree of fluorination. The versatility of fluorinated graphene as a biosensor platform was demonstrated by cyclic voltammetry for different biomolecules

  10. How nanoparticles encapsulating fluorophores allow a double detection of biomolecules by localized surface plasmon resonance and luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Barbillon, G; Faure, A C; Kork, N El; Moretti, P [Universite de Lyon, Universite Lyon 1, CNRS UMR 5620, Laboratoire de Physico-Chimie des Materiaux Luminescents (LPCML), Domaine Scientifique de La Doua, Bat Kastler, 10 rue Andre Marie Ampere 69622 Villeurbanne Cedex (France); Roux, S; Tillement, O [Universite de Lyon, Universite Lyon 1, CNRS UMR 5620, Laboratoire de Physico-Chimie des Materiaux Luminescents (LPCML), Domaine Scientifique de La Doua, Bat Kastler, 10 rue Andre Marie Ampere 69622 Villeurbanne Cedex (France); Ou, M G; Descamps, A; Perriat, P [Materiaux, Ingenierie et Sciences (MATEIS), CNRS UMR 5510, Universite de Lyon, INSA-Lyon, Domaine Scientifique de La Doua, 7 avenue Jean Capelle 69621 Villeurbanne Cedex (France); Vial, A; Bijeon, J-L [Institut Charles Delaunay, CNRS FRE 2848, Laboratoire de Nanotechnologie et d' Instrumentation Optique (LNIO), Universite de Technologie de Troyes, 12 rue Marie Curie BP 2060 10010 Troyes Cedex (France); Marquette, C A [Laboratoire de Genie Enzymatique et Biomoleculaire, UMR 5246 CNRS-ICBMS, Universite de Lyon, Universite Lyon 1, 69622 Villeurbanne Cedex (France); Jacquier, B [Universite de Lyon, Universite Lyon 1, CNRS UMR 5620, Laboratoire de Physico-Chimie des Materiaux Luminescents (LPCML), Domaine Scientifique de La Doua, Bat Kastler, 10 rue Andre Marie Ampere 69622 Villeurbanne Cedex (France)

    2008-01-23

    The paper shows how polysiloxane particles encapsulating fluorophores can be successfully used to detect biotin-streptavidin binding by two types of technique. After functionalization of the particles by streptavidin, the fixation of the biomolecule can indeed be detected by a shift of the localized surface plasmon resonance of the biotinylated gold dots used as substrate and by the luminescence of the fluorophores evidenced by scanning near-field optical microscopy. The development of particles allowing such a double detection opens a route for increasing the reliability of biological detection and for multi-labelling strategies crossing both detection principles.

  11. Association between 8-oxo-7,8-dihydro-2'-deoxyguanosine excretion and risk of postmenopausal breast cancer

    DEFF Research Database (Denmark)

    Loft, Steffen; Olsen, Anja; Møller, Peter;

    2013-01-01

    Oxidative stress may be important in carcinogenesis and a possible risk factor for breast cancer. The urinary excretion of oxidatively generated biomolecules, such as 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), represents biomarkers of oxidative stress, reflecting the rate of global damage to...

  12. 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

  13. 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.

  14. 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…

  15. 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...

  16. How nurses seek and evaluate clinical guidelines on the Internet

    NARCIS (Netherlands)

    Verhoeven, Fenne; Steehouder, Michael F.; Hendrix, Ron M.G.; Gemert-Pijnen, van Julia E.W.C.

    2010-01-01

    Aim: This paper is a report of a study conducted to assess nurses’ information-seeking strategies and problems encountered when seeking clinical guidelines on the Internet, and to investigate the criteria they apply when evaluating the guidelines and the websites communicating the guidelines. - Back

  17. Exploring Reality-Based User Interfaces for Collaborative Information Seeking

    OpenAIRE

    Heilig, Mathias

    2012-01-01

    Information seeking activities such as searching the web or browsing a media library are often considered to be solitary experiences. However, both theoretical and empirical research has demonstrated the importance of collaborative activities during the information seeking process. Students working together to complete assignments, friends looking for joint entertainment opportunities, family members planning a vacation, or colleaguesconducting research for collaborative projects are only few...

  18. A Rent-Seeking Experiment for the Classroom

    Science.gov (United States)

    Strow, Brian Kent; Strow, Claudia Wood

    2007-01-01

    Recent research has demonstrated that active learning techniques improve student comprehension and retention of abstract economic ideas such as rent seeking. Instructors can reinforce the concept of rent seeking with a classroom game, particularly one involving real money. The authors improve upon a game first introduced by Goeree and Holt (1999)…

  19. Seeking Information for School Purposes on the Internet.

    Science.gov (United States)

    Gunn, Holly; Hepburn, Gary

    2003-01-01

    Reports findings of a study in four Nova Scotia public schools of twelfth grade students' information seeking strategies when using the Internet as an information source. Discusses student's knowledge of World Wide Web search engines; how students acquired Internet information seeking knowledge; and how students perceive their ability to locate…

  20. The Prediction of University Students' Willingness to Seek Counseling

    Science.gov (United States)

    Erkan, Serdar; Ozbay, Yasar; Cihangir-Cankaya, Zeynep; Terzi, Serife

    2012-01-01

    The aim of this research is to determine the variables that qualify the help seeking behavior (willingness to seek counseling) of Turkish university students. A total of 5829 college students (2974 females, 2841 males, 14 unknown) from eleven universities in Turkey have participated in the study. Personal Form, Self Concealment Scale, Willingness…

  1. 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)

  2. 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.…

  3. 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.

  4. Sensation seeking in opium abusers compared to normal people

    Directory of Open Access Journals (Sweden)

    2004-05-01

    Full Text Available Recent research shows that it is possible to identify people at risk of substance abuse using some personality variables. Identification of these people might help social planners to deal with these people specifically in their prevention attempts. The aim of this study was to compare the sensation seeking of opium addicted and non-addicted people using the sensation seeking scale. Such a comparison might help to identify personality variables that are effective in turning toward substance abuse. In order to measure the sensation seeking of subjects “Sensation Seeking Scale” (SSS were used. 31 opium abusers were matched to 31 normal controls according to the following variables: age, education, father and mother education. Results showed that opium abusers obtain higher scores on the total sensation seeking score ,“variety seeking” and “experience seeking” subscales.

  5. 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...... 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...... in a study context? Results. Seven studies were identified and reviewed. According to the reported results, use of social media tends to afford certain types of behavior. Specific strategies, tactics and criteria were used when requesting and evaluating information or formulating information needs...

  6. 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.

  7. 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。

  8. Cancer Statistics: Endometrial Cancer

    Science.gov (United States)

    ... a third party. HPF: Did You Know? Endometrial Cancer Endometrial Cancer - Did you know that endometrial cancer ... mfhs0vbvWi8?rel=0 SEER Stat Fact Sheets: Endometrial Cancer Expand All Collapse All Lifetime risk estimates are ...

  9. Biomolecule-assisted Solvothermal Synthesis and Enhanced Visible Light Photocatalytic Performance of Bi2S3/BiOCl Composites

    Institute of Scientific and Technical Information of China (English)

    JIA Zhimin; CHEN Wei; LIU Tianyu; HUANG Ting; LIU Xiaoheng

    2016-01-01

    Novel Bi2S3/BiOCl photocatalysts were successfully synthesized via a facile biomolecule-assisted solvothermal method and biomolecule L-cysteine was used as the sulfur source. The structures, morphology, and optical properties of the synthesized samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, transmission electron microscopy (TEM), and UV-vis diffuse reflectance spectroscopy (DRS). The presence of Bi2S3 in the Bi2S3/BiOCl composites could not only improve the optical properties but also enhance the photocatalytic activities for the degradation of Rhodamine B (RhB) under visible-light irradiation (λ > 420 nm) as compared with single Bi2S3 and BiOCl. Especially, the sample displayed the best performance of the photodegradation when the feed molar ratio of BiCl3 and L-cysteine was 2.4:1, which was about 10 times greater than that of pure BiOCl. The enhanced photocatalytic activities could be ascribed to the effective separation of photoinduced electrons and holes and the photosensitization of dye. Moreover, the possible photodegradation mechanism was also proposed, and the results revealed that the active holes (h+) and superoxide radicals (•O2−) were the main reactive species during photocatalytic degradation.

  10. The biophysical effects of deuterium oxide on biomolecules and living cells through open notebook science

    Science.gov (United States)

    Salvagno, Anthony L.

    induced protein aggregation was possible in H2O, but prevented in the presence of D2O and analyzed via DLS. Deuterium exchange and replacement was observed and quantified using both FT-IR and CRDS. With FT-IR it was possible to identify differences between solvents, while the time-scale of hydrogen-deuterium exchange was quantified for bulk water with CRDS. Using optical tweezers, DNA was overstretched in both H2O and D2O. The average force for DNA overstretching was found to be ~2.5pN higher in D2O compared to H2O. Deuterium oxide has a stabilizing force on biomolecules, which prevents protein denaturing and can affect the timing for cellular processes. It is because of this molecular property that D2O is observed to affect organisms grown with D2O instead of H2O. Despite this, there seems to be an optimal concentration of deuterium which is above the natural concentration of 155.6ppm. In the presence of deuterium depleted water, cells exhibit signs of stress, further demonstrating that deuterium isn't merely tolerated in solution, but actually required as hypothesized by Gilbert N. Lewis in 1934.

  11. The Study of Biomolecule-Substrate Interactions by Single Molecule Force Spectroscopy and Brownian Dynamics Simulations

    Science.gov (United States)

    Cook, Sara Iliafar

    Hybrids of biomolecules and nanomaterials have been identified as promising candidates in the development of novel therapeutics and electronic devices. Single stranded DNA (ssDNA)-bound Single-walled carbon nanotubes (SWCNTs) are of particular interest as they may be the key to solving the challenges that face the carbon nanotube separation technology and because of their potential application in bio-nanomedicine. The ability of ssDNA to form a stable hybrid with CNTs has been attributed to the structure and amphiphilic nature of this macromolecule, enabling the dispersion, sorting and patterned placement of nanotubes. Considering the significant role of ssDNA-CNTs in future technologies and the potential toxicity of such nanomaterials in biological systems, it is essential to gain a quantitative and fundamental understanding on the interactions that allow, weaken or prevent the formation of these hybrids. In this dissertation, we use both experimental and theoretical methods to systematically investigate the major characteristics of these interactions. The free energy of binding of ssDNA homopolymers to solvated carbon nanotubes is one of the key characteristics that determine the stability of such dispersions. We used single molecule force spectroscopy (SMFS), first on graphite and next on single walled carbon nanotubes, to probe and directly quantify the binding strength of ssDNA homopolymer oligomers to these substrates. The force resisting removal of DNA molecules from these surfaces shows characteristic steady-state force plateaus which were distinguishable for each DNA sequence. The free energy of binding per nucleotide for these oligomers on graphite were ranked as T >= A > G >= C (11.3 +/- 0.8 kT, 9.9 +/- 0.4 kT, 8.3 +/- 0.2 kT, and 7.5 +/- 0.8 kT, respectively). On SWCNTs, these interactions decreased in the following order: A > G > T > C, and their magnitude was much larger than on graphite (38.1 +/- 0.2; 33.9 +/- 0.1; 23.3 +/- 0.1; 17.1 +/- 0.1 k

  12. A Review on Information Seeking Behaviour Literature in Iran

    Directory of Open Access Journals (Sweden)

    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.

  13. Cancer - resources

    Science.gov (United States)

    Resources - cancer ... The following organizations are good resources for information on cancer : American Cancer Society -- www.cancer.org Cancer Care -- www.cancercare.org National Cancer Institute -- www.cancer.gov

  14. Cancer Statistics

    Science.gov (United States)

    ... What Is Cancer? Cancer Statistics Cancer Disparities Cancer Statistics Cancer has a major impact on society in ... success of efforts to control and manage cancer. Statistics at a Glance: The Burden of Cancer in ...

  15. Improving radionuclide therapy in prostate cancer patients with metastatic bone pain

    NARCIS (Netherlands)

    Lam, M.G.E.H.

    2009-01-01

    Bone seeking radiopharmaceuticals are indicated in cancer patients with multiple painful skeletal metastases. The majority of these patients are hormone-refractory prostate cancer patients in an advanced stage of their disease. Bone seeking radiopharmaceuticals relieve pain and improve the patients

  16. Modeling Inertia and Variety Seeking Tendencies in Brand Choice Behavior

    OpenAIRE

    Kapil Bawa

    1990-01-01

    Theories of exploratory behavior suggest that inertia and variety-seeking tendencies may coexist within the individual, implying that the same individual may exhibit inertia and variety-seeking at different times depending on his/her choice history. Past research has not allowed for such -consumer variability in these tendencies. The purpose of this study is to present a choice model that allows us to identify such “hybrid” behavior (i.e., a mixture of inertia and variety-seeking), and to dis...

  17. Bureaucratic Tax-Seeking: The Danish Waste Tax

    DEFF Research Database (Denmark)

    Christoffersen, Henrik; Svendsen, Gert Tinggaard

    2000-01-01

    , the absence of a strong and fully informed troop leader prevents rational coordination of collective action. Second, budget maximization leads to overwhelming fiscal pressure because bureaucracies are competing about resources just like fishermen or hunters (here named 'bureaucratic tax-seeking'). Taxing...... are strongly confirmed by the case of the Danish waste tax. Thus, we recommend that bureaucratic institutions should coordinate their tax-seeking efforts to maximize budgets in the long run and that the ministries that collect green tax revenues should not be allowed to control these revenues. Such a budget...... maximization opportunity would kick off a new self-destructive fiscal race among competing tax-seeking bureaucracies....

  18. 6 Common Cancers - Prostate Cancer

    Science.gov (United States)

    ... PSA tests. Read More "6 Common Cancers" Articles Lung Cancer / Breast Cancer / Prostate Cancer / Colorectal Cancer / Skin Cancer / Gynecologic Cancers Spring 2007 Issue: Volume 2 Number 2 Page 10 MedlinePlus | Subscribe | Magazine Information | Contact Us | Viewers & ...

  19. 6 Common Cancers - Colorectal Cancer

    Science.gov (United States)

    ... certain people. Read More "6 Common Cancers" Articles Lung Cancer / Breast Cancer / Prostate Cancer / Colorectal Cancer / Skin Cancer / Gynecologic Cancers Spring 2007 Issue: Volume 2 Number 2 Page 11 MedlinePlus | Subscribe | Magazine Information | Contact Us | Viewers & ...

  20. Metal-ion Speciation in Blood Plasma as a Tool in Predicting the "in vivo" Behaviour of Potential Bone-Seeking Radiopharmaceuticals

    NARCIS (Netherlands)

    Zeevaart, J.R.

    2001-01-01

    In a quest for more effective radiopharmaceuticals for palliation of pain experienced by metastatic bone cancer patients, results obtained with the therapeutic radionuclides 153 SM, 166 Ho and 117mSn complexed to bone-seeking phopsphate ligands are related. As phosphonates are known to enhance the r

  1. Seeking Drug Abuse Treatment: Know What to Ask

    Science.gov (United States)

    ... Abuse Treatment: Know What To Ask » Introduction Seeking Drug Abuse Treatment: Know What To Ask Email Facebook Twitter Introduction The goal of drug abuse treatment is to stop drug use and allow ...

  2. Where has all the antimatter gone? VELO seeks the answer

    CERN Multimedia

    Ormrod, Gill

    2007-01-01

    "Scientists from the Universities of Liverpool and Glasgow have completed work on the inner heart of an experiment which seeks to find out what has happened to all the antimatter created at the start of the Universe." (2 pages)

  3. Cognitive factors influencing women to seek care during pregnancy.

    Science.gov (United States)

    Fisher, M J; Ewigman, B; Campbell, J; Benfer, R; Furbee, L; Zweig, S

    1991-08-01

    To assess the relationship of cognitive factors to a pregnant woman's decision to seek prenatal care, a semi-structured interview instrument was administered to 30 women soon after they were seen for care. A content analysis of interview transcripts was performed to identify variables affecting the decision to seek care. Variables were coded numerically, and those correlated with number of weeks gestation at first visit for pregnancy care were entered into a stepwise linear multiple regression model. Three variables accounted for 74% of the variance in the week of gestation at which pregnancy care began. Women who desired the pregnancy, wished confirmation of the pregnancy, and experienced pregnancy-related symptoms tended to seek care earlier. Results were discussed in terms of the usefulness of this integration of quantitative and qualitative methods for the study of factors related to seeking pregnancy care and the need to consider cognitive factors when designing programs to improve the delivery of prenatal care. PMID:1936719

  4. Effects of air transient spark discharge and helium plasma jet on water, bacteria, cells, and biomolecules.

    Science.gov (United States)

    Hensel, Karol; Kučerová, Katarína; Tarabová, Barbora; Janda, Mário; Machala, Zdenko; Sano, Kaori; Mihai, Cosmin Teodor; Ciorpac, Mitică; Gorgan, Lucian Dragos; Jijie, Roxana; Pohoata, Valentin; Topala, Ionut

    2015-06-06

    Atmospheric pressure DC-driven self-pulsing transient spark (TS) discharge operated in air and pulse-driven dielectric barrier discharge plasma jet (PJ) operated in helium in contact with water solutions were used for inducing chemical effects in water solutions, and the treatment of bacteria (Escherichia coli), mammalian cells (Vero line normal cells, HeLa line cancerous cells), deoxyribonucleic acid (dsDNA), and protein (bovine serum albumin). Two different methods of water solution supply were used in the TS: water electrode system and water spray system. The effects of both TS systems and the PJ were compared, as well as a direct exposure of the solution to the discharge with an indirect exposure to the discharge activated gas flow. The chemical analysis of water solutions was performed by using colorimetric methods of UV-VIS absorption spectrophotometry. The bactericidal effects of the discharges on bacteria were evaluated by standard microbiological plate count method. Viability, apoptosis and cell cycle were assessed in normal and cancerous cells. Viability of cells was evaluated by trypan blue exclusion test, apoptosis by Annexin V-FITC/propidium iodide assay, and cell cycle progression by propidium iodide/RNase test. The effect of the discharges on deoxyribonucleic acid and protein were evaluated by fluorescence and UV absorption spectroscopy. The results of bacterial and mammalian cell viability, apoptosis, and cell cycle clearly show that cold plasma can inactivate bacteria and selectively target cancerous cells, which is very important for possible future development of new plasma therapeutic strategies in biomedicine. The authors found that all investigated bio-effects were stronger with the air TS discharge than with the He PJ, even in indirect exposure.

  5. The Impact of Context on Variety Seeking in Product Choices.

    OpenAIRE

    Menon, Satya; Kahn, Barbara E

    1995-01-01

    One reason consumers seek variety in product choices is to satisfy a need for stimulation. It is suggested that consumers may try to achieve an optimal level of stimulation by balancing the stimulation sought from product choice with the stimulation available from the choice context. Two laboratory experiments are conducted that show that causing changes in the choice context (thus increasing stimulation) decreases the amount of variety seeking subjects exhibit in product choices. Specificall...

  6. Dopamine Regulates Approach-Avoidance in Human Sensation-Seeking

    OpenAIRE

    Norbury, A.; Kurth-Nelson, Z.; Winston, J. S.; Roiser, J.P.; M. Husain

    2015-01-01

    Background: Sensation-seeking is a trait that constitutes an important vulnerability factor for a variety of psychopathologies with high social cost. However, little is understood either about the mechanisms underlying motivation for intense sensory experiences or their neuropharmacological modulation in humans. Methods: Here, we first evaluate a novel paradigm to investigate sensation-seeking in humans. This test probes the extent to which participants choose either to avoid or self-administ...

  7. Sensation seeking in opium abusers compared to normal people

    OpenAIRE

    2004-01-01

    Recent research shows that it is possible to identify people at risk of substance abuse using some personality variables. Identification of these people might help social planners to deal with these people specifically in their prevention attempts. The aim of this study was to compare the sensation seeking of opium addicted and non-addicted people using the sensation seeking scale. Such a comparison might help to identify personality variables that are effective in turning toward substance ab...

  8. Androgen Exposure and Sensation-Seeking in Young Males

    OpenAIRE

    Ellison, Peter; Little, A.; Apicella, Carmel; Dreber, Anna; Gray, Peter B; Campbell, Bruce C

    2008-01-01

    Testosterone is thought to be associated with short attention spans, increased novelty, and thrill seeking and behavioral disinhibition in men. However, there is little empirical evidence for such associations among normal males. Here we test three separate measures of androgenicity; salivary testosterone (current exposure), facial masculinity (pubertal exposure), and 2D:4D digit ratio (prenatal exposure) as predictors of sensation-seeking in young men. Participants were 98 young men between ...

  9. Evaluating Collaborative Search Interfaces with Information Seeking Theory

    OpenAIRE

    Wilson, Max L.; Schraefel, M. C.

    2008-01-01

    Despite the many implicit references to the social aspects of search within Information Seeking and Retrieval research, there has been relatively little work that has specifically investigated the additional requirements for collaborative search software. In this paper we re-assess a recent evaluation framework, designed for individual information seeking experiences, to see a) how it could still be applied to collaborative search software; b) how it could produce additional requirements for ...

  10. Health information-seeking among Latino newcomers - an exploratory study

    OpenAIRE

    Christina Courtright

    2005-01-01

    ntroduction. This exploratory study examines health information-seeking practices among Latin American newcomers to a small city in the United States. The framework locates these practices within social networks, the local institutional context and the use and non-use of information technologies. Method. Semistructured interviews were conducted in Spanish with seven immigrant workers. Interviews elicited incidents of both purposive seeking and accidental encountering of health information. A...

  11. Health care help seeking behaviour among prisoners in Norway

    OpenAIRE

    Nesset Merete; Rustad Åse-Bente; Kjelsberg Ellen; Almvik Roger; Bjørngaard Johan

    2011-01-01

    Abstract Background Prisoners are associated with high health care needs compared with the general population. This study aims to investigate prisoners' use of health service. Methods A cross-sectional study of 29 prisons in central and southern parts of Norway. A questionnaire was distributed to 1, 454 prisoners (90% response rate). Multilevel analyses were employed to analyse help seeking behaviour among the prisoners. Results Help seeking was substantially associated with sleep problems an...

  12. Information Seeking in Context: Results of Graduate Student Interviews

    OpenAIRE

    Marg Sloan; Kim McPhee

    2013-01-01

    Abstract We conducted a qualitative research study examining the information seeking behaviours of Psychology, Sociology and Women’s Studies graduate students at a large research intensive university to determine how graduate students find information; the roles that faculty members, fellow graduate students and librarians play in the information search; and graduate students’ knowledge of information resources and services. The context of graduate student information seeking was uncovered...

  13. Sensitivity and Resolution Enhanced Solid-State NMR for Paramagnetic Systems and Biomolecules under Very Fast Magic Angle Spinning

    KAUST Repository

    Parthasarathy, Sudhakar

    2013-09-17

    Recent research in fast magic angle spinning (MAS) methods has drastically improved the resolution and sensitivity of NMR spectroscopy of biomolecules and materials in solids. In this Account, we summarize recent and ongoing developments in this area by presenting (13)C and (1)H solid-state NMR (SSNMR) studies on paramagnetic systems and biomolecules under fast MAS from our laboratories. First, we describe how very fast MAS (VFMAS) at the spinning speed of at least 20 kHz allows us to overcome major difficulties in (1)H and (13)C high-resolution SSNMR of paramagnetic systems. As a result, we can enhance both sensitivity and resolution by up to a few orders of magnitude. Using fast recycling (∼ms/scan) with short (1)H T1 values, we can perform (1)H SSNMR microanalysis of paramagnetic systems on the microgram scale with greatly improved sensitivity over that observed for diamagnetic systems. Second, we discuss how VFMAS at a spinning speed greater than ∼40 kHz can enhance the sensitivity and resolution of (13)C biomolecular SSNMR measurements. Low-power (1)H decoupling schemes under VFMAS offer excellent spectral resolution for (13)C SSNMR by nominal (1)H RF irradiation at ∼10 kHz. By combining the VFMAS approach with enhanced (1)H T1 relaxation by paramagnetic doping, we can achieve extremely fast recycling in modern biomolecular SSNMR experiments. Experiments with (13)C-labeled ubiquitin doped with 10 mM Cu-EDTA demonstrate how effectively this new approach, called paramagnetic assisted condensed data collection (PACC), enhances the sensitivity. Lastly, we examine (13)C SSNMR measurements for biomolecules under faster MAS at a higher field. Our preliminary (13)C SSNMR data of Aβ amyloid fibrils and GB1 microcrystals acquired at (1)H NMR frequencies of 750-800 MHz suggest that the combined use of the PACC approach and ultrahigh fields could allow for routine multidimensional SSNMR analyses of proteins at the 50-200 nmol level. Also, we briefly discuss the

  14. Children's Attentional Processing of Mother and Proximity Seeking.

    Directory of Open Access Journals (Sweden)

    Guy Bosmans

    Full Text Available Attachment expectations regarding the availability of mother as a source for support are supposed to influence distressed children's support seeking behavior. Because research is needed to better understand the mechanisms related to support seeking behavior, this study tested the hypothesis that the cognitive processing of mother-related information is linked to proximity and support seeking behavior. Uncertainty in maternal support has been shown to be characterized by a biased attentional encoding of mother, reducing the breadth of children's attentional field around her. We investigated whether this attentional bias is related to how long distressed children wait before seeking their mother's proximity. Thirty-three children (9-11 years participated in this study that consisted of experimental tasks to measure attentional breadth and to observe proximity seeking behavior and of questionnaires to measure confidence in maternal support and experienced distress. Results suggested that distressed children with a more narrow attentional field around their mother wait longer to seek her proximity. Key Message: These findings provide a first support for the hypothesis that the attentional processing of mother is related to children's attachment behavior.

  15. Who Seeks Help Online for Self-Injury?

    Science.gov (United States)

    Frost, Mareka; Casey, Leanne

    2016-01-01

    The objective of this study was to identify differences between young people who seek help online for self-injury and those who self-injure but do not seek help online, in order to improve online services for young people at high risk of suicide. Young people reporting a history of self-injury (N = 679) were identified as part of larger study (N = 1,463) exploring help-seeking. One third of young people with a history of self-injury reported online help-seeking for self-injury. Online help-seekers were significantly more distressed, suicidal, and had a greater degree of self-injury compared to those who did not seek help online. The Internet provides an important form of support to the most at risk young people in this population, and may be a proximal step to face-to-face help-seeking. Further research is required to investigate the forms of support currently accessed by young people online, and their effectiveness. PMID:25706352

  16. Study of sodium arsenite induced biochemical changes on certain biomolecules of the freshwater catfish Clarias batrachus

    Directory of Open Access Journals (Sweden)

    Randhir Kumar

    2012-01-01

    Full Text Available Toxic impact of sublethal concentration (1 mg/L; 5% of 96h LC50 value of sodium arsenite (NaAsO2 on certain biomolecules (proteins, nucleic acids, lipids, and glycogen of five tissue components (muscles, liver, brain, skin, and gills of the freshwater catfish Clarias batrachus was analysed. The important toxic manifestations include marked decrease in the concentration of proteins (21.72-45.42% in muscles; 3.42-53.94% in liver; 15.39-45.42% in brain; 15.40-4.00% in skin and 11.35-64.13% in gills, DNA (0.55-22.95% in muscles; 8.33-14.06% in liver; 5.30-18.40% in brain; 13.57-52.80% in skin; and 12.38-31.01% in gills, RNA (42.68-76.16% in muscles; 10.68-39.75% in liver; 5.66-29.05% in brain; 7.72-27.93% in skin and 21.47-44.38% in gills and glycogen (24.00-51.72% in muscles; 49.11-72.45% in liver; 11.49-26.03% in brain; 26.13-38.05% in skin and 17.80-37.97% in gills. Excepting liver where the lipid content increases (15.82-24.13%, the fat content also showed depletion in their concentration (10.40-29.83% in muscles; 8.30-34.45% in brain; 8.94-31.47% in skin and 12.75-28.86% in gills, in the rest of the organ systems.Foi analisado o impacto tóxico da concentração subletal (1 mg/L; 5% do valor de LC50 de 96h do arsenito de sódio (NaAsO2 sobre certas biomoléculas (proteinas, ácidos nucleicos, lipídios e glicogênio de cinco tecidos (músculos, fígado, cérebro, pele e brânquias do bagre Clarias batrachus. As manifestações tóxicas importantes incluiram o decréscimo acentuado na concentração de proteinas (21,72-45,42% nos músculos; 3,42-53,94% no fígado; 15,39-45,42% no cérebro; 15,40-4,00% na pele e 11,35-64,13% nas brânquias, DNA (0,55-22,95% nos músculos; 8,33-14,06% no fígado; 5,30-18,40% no cérebro; 13,57-52,80% na pele e 12,38-31,01% nas brânquias, RNA (42,68-76,16% nos músculos; 10,68-39,75% no fígado; 5,66-29,05% no cérebro; 7,72-27,93% na pele e 21,47-44,38% nas brânquias e glicogênio (24,00-51,72% nos músculos; 49

  17. Intramammary lymph nodes: a question seeking for an answer or an answer seeking for a question?

    Science.gov (United States)

    Troupis, T; Michalinos, A; Skandalakis, P

    2012-10-01

    Intramammary lymph nodes have not received for a long time enough attention from the medical literature and thus many of their characteristics are not sufficiently explored. Their incidence at various studies ranges between 0, 7 and 48%. They may be found in all breast quadrants but usually at the Upper Outer Quadrant (UOQ). Their radiological image at mammography is that of a well circumscribed density with an area of lower density at centre representing the hilum and at ultrasonography of a hypoechoic, circumscribed mass with an echogenic hilum. Their role in lymphatic drainage of breast regions is important although it is not known if they represent true sentinel nodes or if lymphatic drainage to them comes from ectopic, independently developed pathways. Intramammary Lymph Nodes are involved in a variety of clinical situations including benign situations, tumor metastasis, breast lymphoma and breast cancer. Their importance over breast cancer is not fully defined but there is evidence that they worsen prognosis and they may change therapeutic decisions. Breast cancer and Breast lymphoma can coexist and interfere.

  18. “Smart”nanomaterials for cancer therapy

    Institute of Scientific and Technical Information of China (English)

    LE; GUYADER; Laurent

    2010-01-01

    Recent development in nanotechnology has provided new tools for cancer therapy and diagnostics.Because of their small size,nanoscale devices readily interact with biomolecules both on the cell surface and inside the cell.Nanomaterials,such as fullerenes and their derivatives,are effective in terms of interactions with the immune system and have great potential as anticancer drugs.Comparatively,other nanomaterials are able to load active drugs to cancer cells by selectively using the unique tumor environment,such as their enhanced permeability,retention effect and the specific acidic microenvironment.Multifunctional and multiplexed nanoparticles,as the next generation of nanoparticles,are now being extensively investigated and are promising tools to achieve personalized and tailored cancer treatments.

  19. Energy transfer mechanisms in photobiological reactions. Final report, 1 April 1960--31 March 1979. [Photodynamic processes in selected biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Spikes, J.D.

    1979-03-31

    This project was concerned primarily with studies of the mechanisms of the sensitized photooxidation of selected biomolecules using a variety of phtosensitizers. Such reactions are often termed photodynamic processes. In particular we have carried out steady-state kinetic studies, flash photolysis and spectral studies, and product formation studies of the sensitized photooxidation of the five susceptible amino acids (cycteine, histidine, methonine, tryptophan, and tyrosine) and their derivatives, as well as purines and pyrimidines. A number of studies were also carried out on the mechanisms of the photodynamic inactivation of enzymes (trypsin, ribonuclease, lysozyme). Mechanism of photosensitization were studied using a variety of sensitizers including flavins, porphyrins, and a number of synthetic dyes (substituted fluoresceins, acridines, thyazines).

  20. Oxidative destruction of biomolecules by gasoline engine exhaust products and detoxifying effects of the three-way catalytic converter.

    Science.gov (United States)

    Blaurock, B; Hippeli, S; Metz, N; Elstner, E F

    1992-01-01

    Aqueous solutions of engine exhaust condensation products were derived from cars powered by diesel or four-stroke gasoline engines (with and without three-way catalytic converter). The cars were operated on a static test platform. Samples of the different exhaust solutions accumulated in a Grimmer-type distillation trap (VDI 3872) during standard test programs (Federal Test Procedure) were incubated with important biomolecules. As indicators of reactive oxygen species or oxidative destruction, ascorbic acid, cysteine, glutathione, serum albumin, the enzymes glycerinaldehyde phosphate dehydrogenase and xanthine oxidase, and the oxygen free-radical indicator keto-methylthiobutyrate were used. During and after the incubations, oxygen activation (consumption) and oxidative destruction were determined. Comparison of the oxidative activities of the different types of exhaust condensates clearly showed that the exhaust condensate derived from the four-stroke car equipped with a three-way catalytic converter exhibited by far the lowest oxidative and destructive power. PMID:1283938

  1. Effect of solution concentration on the structured order and optical properties of short-chain polyene biomolecules

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    We have measured the Raman spectra and UV-Vis absorption spectra of linear polyene biomolecules(β-carotene and lycopene) in CS2 at low concentrations(10-6-10-10 mol/L).With decreasing concentration,all the carbon-carbon vibrations form a coherent mode in ordered β-carotene and lycopene due to extended π-conjugation that gives strong electron-phonon coupling,which leads to an anomalous experimental phenomenon.We observed an extremely high Raman scattering cross section(RSCS) and the Raman activities in β-carotene and lycopene are characterized by intensive overtones and combinations.Further,the UV-Vis absorption bands become narrower.

  2. Computational methods to study the structure and dynamics of biomolecules and biomolecular processes from bioinformatics to molecular quantum mechanics

    CERN Document Server

    2014-01-01

    Since the second half of the 20th century machine computations have played a critical role in science and engineering. Computer-based techniques have become especially important in molecular biology, since they often represent the only viable way to gain insights into the behavior of a biological system as a whole. The complexity of biological systems, which usually needs to be analyzed on different time- and size-scales and with different levels of accuracy, requires the application of different approaches, ranging from comparative analysis of sequences and structural databases, to the analysis of networks of interdependence between cell components and processes, through coarse-grained modeling to atomically detailed simulations, and finally to molecular quantum mechanics. This book provides a comprehensive overview of modern computer-based techniques for computing the structure, properties and dynamics of biomolecules and biomolecular processes. The twenty-two chapters, written by scientists from all over t...

  3. Fabrication of non-enzymatic biosensor based on metallic catalyst-TiO2 hollow sphere nanocomposite for determining biomolecules.

    Science.gov (United States)

    Kwen, Hai-Doo; Yang, Hee-Soo; Lee, In-Ho; Choi, Seong-Ho

    2012-07-01

    A PtRu@TiO2-hollow nanocomposite for the detection of biomolecules was synthesized by chemical reduction. First, poly(styrene-co-vinylphenylboronic acid), PSB, was prepared as a template (approximately 250 nm) by surfactant-free emulsion polymerization. Second, PSB/TiO2 core-shell spheres were prepared by sol-gel reaction. Finally, TiO2 hollow spheres (TiO2-H) were then formed after removing the PSB template by calcination at 450 degrees C under air atmosphere. To prepare the electrocatalyst, PtRu nanoparticles (NPs) were deposited onto the TiO2-H surface by chemical reduction. The prepared PtRu@TiO2-H nanocomposite was characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and elemental analysis. A non-enzymatic sensor was fabricated by depositing the as-prepared PtRu@TiO2-H nanocomposite on the surface of a glassy carbon electrode (GCE), which was prepared by a hand casting method with Nafion solution as a binder. The sensor was tested as a biomolecule sensor, especially for the detection of glucose and dopamine. The cyclic voltammograms (CV) obtained during the oxidation studies revealed that the PtRu@TiO2-H nanocomposite showed better catalytic function toward the oxidation of dopamine. The sensing range of the non-enzymatic sensor for glucose was 5.0-100 mM in a phosphate buffer. The results demonstrated the potential usefulness of this bimetallic@TiO2-H bifunctional catalyst for biosensor applications. PMID:22966548

  4. Design of a molecular imprinting biosensor with multi-scale roughness for detection across a broad spectrum of biomolecules.

    Science.gov (United States)

    Yu, Yingjie; Zhang, Qi; Chang, Chung-Chueh; Liu, Ying; Yang, Zhenhua; Guo, Yichen; Wang, Yantian; Galanakis, Dennis K; Levon, Kalle; Rafailovich, Miriam

    2016-10-01

    The molecular imprinting technique has tremendous applications in artificial enzymes, bioseparation, and sensor devices. In this study, a novel molecular imprinting (MI) biosensor platform was developed for the detection of a broad range of biomolecules with different sizes. Previously this method has been applied to 2D molecular imprinting, where the height of the self-assembled monolayer (SAM) of around 2 nm limited the maximum dimensions of the molecule that can be imprinted to create template-shaped cavities. In order to match the size of the imprinted molecules with the height of the SAM, we propose a model for 3D molecular imprinting where the analyte is sequestered within a niche created by the surface roughness. The SAM is assembled on the walls of the niche, forming a 3D pattern of the analyte uniquely molded to its contour. Surfaces with multi-scale roughness were prepared by evaporation of gold onto electropolished (smooth) and unpolished (rough) Si wafers, where the native roughness was found to have a normal distribution centered around 5 and 90 nm respectively. Our studies using molecules with size ranging on a nanometer scale, from proteins of a few nanometers to bacteria of hundreds of nanometers, showed that when the size of the analyte matched the roughness range of the gold surface, the molecular imprinting process was optimized for the best biosensing performance. After optimization, the MI biosensor platform enabled the identification and quantification of a broad range of biomolecules with great discrimination abilities. Hemoglobin under different pH values and several mutated fibrinogen molecules can also be well differentiated through the test.

  5. Very stable 188Re-S4 chelates for labelling biomolecules. Preparation with highly concentrated perrhenate eluates

    International Nuclear Information System (INIS)

    Aim: The preparation and stability of a new 188Re-S4-complex [S4 (1-aza-18-crown-6)(O)C-C(SH)-C(SH)-C(O)NH-(CH2)3-NH-(CH2)3-NHC(O)- = C(SH)- C(SH )-C(O)(1-aza-18-crown-6)] was studied at therapeutic relevant radioactive concentrations. The results were compared with 188Re-MAG3 (MAG3: mercaptoacetyltriglycine) and 188Re-DMSA preparations (DMSA: dimercaptosuccinic acid) performed with the same highly concentrated [188Re]perrhenate solution (12-15 GBq/ml). Methods: The 188Re complexes were prepared by direct reduction of perrhenate (188Re-S4-complex) as well as via the 188Re-EDTA precursor complex (188Re-MAG3, 188Re-DMSA). The preparations were stabilised with 15 mg of ascorbic acid and analysed after 1, 2, and 24 hours by TLC and HPLC. Additionally, in vitro and in vivo stability studies were performed with the purified complexes. Results: After stabilisation with 15 mg of ascorbic acid, all of the complexes were nearly stable under nitrogen for hours, and only 2-8% of perrhenate was observed after 24 h. In contrast, only the 188Re-S4 complex was completely stable in vitro and in all investigated in vivo samples after separation of ligand excess and reducing agent by HPLC. Conclusion: The bridging amine group or free carboxylic groups of the S4-ligand framework make available reactive positions for coupling biomolecules to the chelate. Thus it appears that the new 188Re-S4 complexes offer the possibility of stable and high specific activity labelling of biomolecules for therapeutic application. (orig.)

  6. Nucleus incertus Orexin2 receptors mediate alcohol seeking in rats.

    Science.gov (United States)

    Kastman, Hanna E; Blasiak, Anna; Walker, Leigh; Siwiec, Marcin; Krstew, Elena V; Gundlach, Andrew L; Lawrence, Andrew J

    2016-11-01

    Alcoholism is a chronic relapsing disorder and a major global health problem. Stress is a key precipitant of relapse in human alcoholics and in animal models of alcohol seeking. The brainstem nucleus incertus (NI) contains a population of relaxin-3 neurons that are highly responsive to psychological stressors; and the ascending NI relaxin-3/RXFP3 signalling system is implicated in stress-induced reinstatement of alcohol seeking. The NI receives orexinergic innervation and expresses orexin1 (OX1) and orexin2 (OX2) receptor mRNA. In alcohol-preferring (iP) rats, we examined the impact of yohimbine-induced reinstatement of alcohol seeking on orexin neuronal activation, and the effect of bilateral injections into NI of the OX1 receptor antagonist, SB-334867 (n = 16) or the OX2 receptor antagonist, TCS-OX2-29 (n = 8) on stress-induced reinstatement of alcohol seeking. We also assessed the effects of orexin-A on NI neuronal activity and the involvement of OX1 and OX2 receptors using whole cell patch-clamp recordings in rat brain slices. Yohimbine-induced reinstatement of alcohol seeking activated orexin neurons. Bilateral NI injections of TCS-OX2-29 attenuated yohimbine-induced reinstatement of alcohol seeking. In contrast, intra-NI injection of SB-334867 had no significant effect. In line with these data, orexin-A (600 nM) depolarized a majority of NI neurons recorded in coronal brain slices (18/28 cells), effects prevented by bath application of TCS-OX2-29 (10 μM), but not SB-334867 (10 μM). These data suggest an excitatory orexinergic input to NI contributes to yohimbine-induced reinstatement of alcohol seeking, predominantly via OX2 receptor signalling. PMID:27395787

  7. Vulva cancer

    Science.gov (United States)

    Cancer - vulva; Cancer - perineum; Cancer - vulvar; Genital warts - vulvar cancer; HPV - vulvar cancer ... cells. Other types of cancers found on the vulva are: Adenocarcinoma Basal cell carcinoma Melanoma Sarcoma Vulvar ...

  8. Colon cancer

    Science.gov (United States)

    Colorectal cancer; Cancer - colon; Rectal cancer; Cancer - rectum; Adenocarcinoma - colon; Colon - adenocarcinoma ... In the United States, colorectal cancer is one of the leading causes of deaths due to cancer. Early diagnosis can often lead to a complete cure. Almost ...

  9. Report of the research co-ordination meeting on labelling techniques of biomolecules for targeted radiotherapy

    International Nuclear Information System (INIS)

    The CRP's focus is on the preparation of site-specific radiopharmaceuticals labelled with with β- emitters for the treatment of cancer. The radiopharmaceuticals should be designed in such a way to deliver the therapeutic doses with high specificity to tumour sites and with minimum dose to other organs. The 2nd Research Co-ordination Meeting (RCM) took place in Mumbai, India from 31 January to 4 February 2000. The present report includes the results of all the participants including the report of the participant from Pakistan who could not attend the meeting. During the second RCM, three main aspects were dealt with viz. the different therapeutic isotopes studied, different carrier molecules like peptides and antibody and the biological aspects of these preparations

  10. Report of the research co-ordination meeting on labelling techniques of biomolecules for targeted radiotherapy

    International Nuclear Information System (INIS)

    The CRP's focus is on the preparation of site-specific radiopharmaceuticals labelled with β-emitters for the treatment of cancer. The radiopharmaceuticals should be designed in such a way to deliver the therapeutic doses with high specificity to tumour sites and with minimum dose to other organs. The 2. Research Co-ordination Meeting (RCM) took place in Mumbai, India from 31 January to 4 February 2000. The present report includes the results of all the participants including the report of the participant from Pakistan who could not attend the meeting. During the second RCM, three main aspects were dealt with viz. the different therapeutic isotopes studied, different carrier molecules like peptides and antibody and the biological aspects of these preparations

  11. Facile synthesis of Ag dendrites on Al foil via galvanic replacement reaction with [Ag(NH3)2]Cl for ultrasensitive SERS detecting of biomolecules

    International Nuclear Information System (INIS)

    Symmetric silver dendrites have been synthesized on commercial aluminum foil via galvanic replacement reaction with [Ag(NH3)2]Cl. This process is facile and environmentally friendly, without the use of any templates, surfactants or oxidants, and also avoiding the introduction of fluoride anions as a strong toxicity resulting in hypocalcemia. The products were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM) and X-ray diffraction (XRD). SEM characterizations and electrochemical measurements including an electrochemical direct current polarization method and OCP-t technique demonstrate that chloride has proven to be the key factor to the formation of well-defined dendritic shape. The as-prepared Ag dendrites are developed as a surface-enhanced Raman scattering (SERS)-active platform for detection of folic acid, DNA and RNA with well resolved bands and high Raman intensities. The detection concentration for the three biomolecules reaches the level of 10−12 M, and thus the symmetric silver dendrites can potentially be employed as effective SERS sensors for label-free and ultrasensitive biomolecule detection. - Highlights: • Simple galvanic replacement is used to synthesize Ag dendrites on commercial Al foils. • This method avoids the introduction of fluoride anions. • The as-prepared dendrites exhibit high SERS activities for biomolecules. • The detection concentration for the biomolecules reaches the level of 10−12 M

  12. Facile synthesis of Ag dendrites on Al foil via galvanic replacement reaction with [Ag(NH{sub 3}){sub 2}]Cl for ultrasensitive SERS detecting of biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Jiajia; Ye, Weichun [Department of Chemistry, Lanzhou University, Lanzhou 73000 (China); Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou 73000 (China); Wang, Chunming, E-mail: wangcm@lzu.edu.cn [Department of Chemistry, Lanzhou University, Lanzhou 73000 (China); Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou 73000 (China)

    2013-08-15

    Symmetric silver dendrites have been synthesized on commercial aluminum foil via galvanic replacement reaction with [Ag(NH{sub 3}){sub 2}]Cl. This process is facile and environmentally friendly, without the use of any templates, surfactants or oxidants, and also avoiding the introduction of fluoride anions as a strong toxicity resulting in hypocalcemia. The products were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM) and X-ray diffraction (XRD). SEM characterizations and electrochemical measurements including an electrochemical direct current polarization method and OCP-t technique demonstrate that chloride has proven to be the key factor to the formation of well-defined dendritic shape. The as-prepared Ag dendrites are developed as a surface-enhanced Raman scattering (SERS)-active platform for detection of folic acid, DNA and RNA with well resolved bands and high Raman intensities. The detection concentration for the three biomolecules reaches the level of 10{sup −12} M, and thus the symmetric silver dendrites can potentially be employed as effective SERS sensors for label-free and ultrasensitive biomolecule detection. - Highlights: • Simple galvanic replacement is used to synthesize Ag dendrites on commercial Al foils. • This method avoids the introduction of fluoride anions. • The as-prepared dendrites exhibit high SERS activities for biomolecules. • The detection concentration for the biomolecules reaches the level of 10{sup −12} M.

  13. Unraveling low-resolution structural data of large biomolecules by constructing atomic models with experiment-targeted parallel cascade selection simulations

    Science.gov (United States)

    Peng, Junhui; Zhang, Zhiyong

    2016-07-01

    Various low-resolution experimental techniques have gained more and more popularity in obtaining structural information of large biomolecules. In order to interpret the low-resolution structural data properly, one may need to construct an atomic model of the biomolecule by fitting the data using computer simulations. Here we develop, to our knowledge, a new computational tool for such integrative modeling by taking the advantage of an efficient sampling technique called parallel cascade selection (PaCS) simulation. For given low-resolution structural data, this PaCS-Fit method converts it into a scoring function. After an initial simulation starting from a known structure of the biomolecule, the scoring function is used to pick conformations for next cycle of multiple independent simulations. By this iterative screening-after-sampling strategy, the biomolecule may be driven towards a conformation that fits well with the low-resolution data. Our method has been validated using three proteins with small-angle X-ray scattering data and two proteins with electron microscopy data. In all benchmark tests, high-quality atomic models, with generally 1–3 Å from the target structures, are obtained. Since our tool does not need to add any biasing potential in the simulations to deform the structure, any type of low-resolution data can be implemented conveniently.

  14. Microspheres Assembled from Chitosan-Graft-Poly(lactic acid) Micelle-Like Core-Shell Nanospheres for Distinctly Controlled Release of Hydrophobic and Hydrophilic Biomolecules.

    Science.gov (United States)

    Niu, Xufeng; Liu, Zhongning; Hu, Jiang; Rambhia, Kunal J; Fan, Yubo; Ma, Peter X

    2016-07-01

    To simultaneously control inflammation and facilitate dentin regeneration, a copolymeric micelle-in-microsphere platform is developed in this study, aiming to simultaneously release a hydrophobic drug to suppress inflammation and a hydrophilic biomolecule to enhance odontogenic differentiation of dental pulp stem cells in a distinctly controlled fashion. A series of chitosan-graft-poly(lactic acid) copolymers is synthesized with varying lactic acid and chitosan weight ratios, self-assembled into nanoscale micelle-like core-shell structures in an aqueous system, and subsequently crosslinked into microspheres through electrostatic interaction with sodium tripolyphosphate. A hydrophobic biomolecule either coumarin-6 or fluocinolone acetonide (FA) is encapsulated into the hydrophobic cores of the micelles, while a hydrophilic biomolecule either bovine serum albumin or bone morphogenetic protein 2 (BMP-2) is entrapped in the hydrophilic shells and the interspaces among the micelles. Both hydrophobic and hydrophilic biomolecules are delivered with distinct and tunable release patterns. Delivery of FA and BMP-2 simultaneously suppresses inflammation and enhances odontogenesis, resulting in significantly enhanced mineralized tissue regeneration. This result also demonstrates the potential for this novel delivery system to deliver multiple therapeutics and to achieve synergistic effects. PMID:26987445

  15. Unraveling low-resolution structural data of large biomolecules by constructing atomic models with experiment-targeted parallel cascade selection simulations

    Science.gov (United States)

    Peng, Junhui; Zhang, Zhiyong

    2016-07-01

    Various low-resolution experimental techniques have gained more and more popularity in obtaining structural information of large biomolecules. In order to interpret the low-resolution structural data properly, one may need to construct an atomic model of the biomolecule by fitting the data using computer simulations. Here we develop, to our knowledge, a new computational tool for such integrative modeling by taking the advantage of an efficient sampling technique called parallel cascade selection (PaCS) simulation. For given low-resolution structural data, this PaCS-Fit method converts it into a scoring function. After an initial simulation starting from a known structure of the biomolecule, the scoring function is used to pick conformations for next cycle of multiple independent simulations. By this iterative screening-after-sampling strategy, the biomolecule may be driven towards a conformation that fits well with the low-resolution data. Our method has been validated using three proteins with small-angle X-ray scattering data and two proteins with electron microscopy data. In all benchmark tests, high-quality atomic models, with generally 1-3 Å from the target structures, are obtained. Since our tool does not need to add any biasing potential in the simulations to deform the structure, any type of low-resolution data can be implemented conveniently.

  16. Nicking endonuclease-assisted signal amplification of a split molecular aptamer beacon for biomolecule detection using graphene oxide as a sensing platform.

    Science.gov (United States)

    Li, Xiang; Ding, Xuelian; Fan, Jing

    2015-12-01

    Sensitive and selective detection of ultralow concentrations of specific biomolecules is important in early clinical diagnoses and biomedical applications. Many types of aptasensors have been developed for the detection of various biomolecules, but usually suffer from false positive signals and high background signals. In this work, we have developed an amplified fluorescence aptasensor platform for ultrasensitive biomolecule detection based on enzyme-assisted target-recycling signal amplification and graphene oxide. By using a split molecular aptamer beacon and a nicking enzyme, the typical problem of false positive signals can be effectively resolved. Only in the presence of a target biomolecule, the sensor system is able to generate a positive signal, which significantly improves the selectivity of the aptasensor. Moreover, using graphene oxide as a super-quencher can effectively reduce the high background signal of a sensing platform. We select vascular endothelial growth factor (VEGF) and adenosine triphosphate (ATP) as model analytes in the current proof-of-concept experiments. It is shown that under optimized conditions, our strategy exhibits high sensitivity and selectivity for the quantification of VEGF and ATP with a low detection limit (1 pM and 4 nM, respectively). In addition, this biosensor has been successfully utilized in the analysis of real biological samples.

  17. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... Renal Cell) Cancer Leukemia Lung Cancer Lymphoma Pancreatic Cancer Prostate Cancer Skin Cancer Thyroid Cancer Uterine Cancer All ... Cancer Biology Cancer Genomics Causes of Cancer Diagnosis Prevention Screening & Early Detection Treatment Cancer & Public Health Cancer ...

  18. Tobacco and Cancer

    Science.gov (United States)

    ... Cancer? Breast Cancer Colon/Rectum Cancer Lung Cancer Prostate Cancer Skin Cancer Show All Cancer Types News and Features Cancer Glossary ACS Bookstore Cancer Information Cancer Basics Cancer Prevention & Detection Signs & Symptoms of Cancer Treatments & Side Effects ...

  19. Stages of Prostate Cancer

    Science.gov (United States)

    ... Renal Cell) Cancer Leukemia Lung Cancer Lymphoma Pancreatic Cancer Prostate Cancer Skin Cancer Thyroid Cancer Uterine Cancer All ... Cancer Treatment Prostate Cancer Prevention Genetics of Prostate Cancer Prostate Cancer Screening Research Prostate Cancer Treatment (PDQ®)–Patient ...

  20. Drug Addiction Endophenotypes: Impulsive Versus Sensation-Seeking Personality Traits

    Science.gov (United States)

    Ersche, Karen D.; Turton, Abigail J.; Pradhan, Shachi; Bullmore, Edward T.; Robbins, Trevor W.

    2010-01-01

    Background Genetic factors have been implicated in the development of substance abuse disorders, but the role of pre-existing vulnerability in addiction is still poorly understood. Personality traits of impulsivity and sensation-seeking are highly prevalent in chronic drug users and have been linked with an increased risk for substance abuse. However, it has not been clear whether these personality traits are a cause or an effect of stimulant drug dependence. Method We compared self-reported levels of impulsivity and sensation-seeking between 30 sibling pairs of stimulant-dependent individuals and their biological brothers/sisters who did not have a significant drug-taking history and 30 unrelated, nondrug-taking control volunteers. Results Siblings of chronic stimulant users reported significantly higher levels of trait-impulsivity than control volunteers but did not differ from control volunteers with regard to sensation-seeking traits. Stimulant-dependent individuals reported significantly higher levels of impulsivity and sensation-seeking compared with both their siblings and control volunteers. Conclusions These data indicate that impulsivity is a behavioral endophenotype mediating risk for stimulant dependence that may be exacerbated by chronic drug exposure, whereas abnormal sensation-seeking is more likely to be an effect of stimulant drug abuse. PMID:20678754