105 research outputs found
Connectivity effects in the segmental self- and cross-reorientation of unentangled polymer melts
The segmental (bond) rotational dynamics in a polymer melt of unentangled, linear bead-spring chains is studied by molecular dynamics simulations. To single out the connectivity effects, states with limited deviations from the Gaussian behavior of the linear displacement are considered. Both the self and the cross bond-bond correlations with rank ℓ=1,2 are studied in detail. For ℓ=1 the correlation functions are precisely described by expressions involving the correlation functions of the chain modes. Several approximations concerning both the self- and the cross-correlations with ℓ=1,2 are developed and assessed. It is found that the simplified description of the excluded volume static effects derived elsewhere [D. Molin et al., J. Phys.: Condens. Matter 18, 7543 (2006)] well accounts for the short time cross-correlations. It also allows a proper modification of the Rouse theory which provides quantitative account of the intermediate and the long time decay of the rotational correlations with ℓ=1
Perceptions about data-informed decisions: an assessment of information-use in high HIV-prevalence settings in South Africa
BACKGROUND: Information-use is an integral component of a routine health information system and essential to
influence policy-making, program actions and research. Despite an increased amount of routine data collected,
planning and resource-allocation decisions made by health managers for managing HIV programs are often not
based on data. This study investigated the use of information, and barriers to using routine data for monitoring the
prevention of mother-to-child transmission of HIV (PMTCT) programs in two high HIV-prevalence districts in South
Africa.
METHODS: We undertook an observational study using a multi-method approach, including an inventory of facility
records and reports. The performance of routine information systems management (PRISM) diagnostic ‘Use of
Information’ tool was used to assess the PMTCT information system for evidence of data use in 57 health facilities
in two districts. Twenty-two in-depth interviews were conducted with key informants to investigate barriers to
information use in decision-making. Participants were purposively selected based on their positions and experience
with either producing PMTCT data and/or using data for management purposes. We computed descriptive statistics
and used a general inductive approach to analyze the qualitative data.
RESULTS: Despite the availability of mechanisms and processes to facilitate information-use in about two-thirds of the
facilities, evidence of information-use (i.e., indication of some form of information-use in available RHIS reports) was
demonstrated in 53% of the facilities. Information was inadequately used at district and facility levels to inform
decisions and planning, but was selectively used for reporting and monitoring program outputs at the provincial
level. The inadequate use of information stemmed from organizational issues such as the lack of a culture of
information-use, lack of trust in the data, and the inability of program and facility managers to analyze, interpret
and use information.
CONCLCUSIONS: Managers’ inability to use information implied that decisions for program implementation and improving
service delivery were not always based on data. This lack of data use could influence the delivery of health care services
negatively. Facility and program managers should be provided with opportunities for capacity development as well as
practice-based, in-service training, and be supported to use information for planning, management and decision-making
Kaemika app, Integrating protocols and chemical simulation
Kaemika is an app available on the four major app stores. It provides
deterministic and stochastic simulation, supporting natural chemical notation
enhanced with recursive and conditional generation of chemical reaction
networks. It has a liquid-handling protocol sublanguage compiled to a virtual
digital microfluidic device. Chemical and microfluidic simulations can be
interleaved for full experimental-cycle modeling. A novel and unambiguous
representation of directed multigraphs is used to lay out chemical reaction
networks in graphical form
A Scoping Review of Home Produced Heroin and Amphetamine Type Stimulant Substitutes: Implications for Prevention, Treatment and Policy
Several home-produced substances such as krokodil and boltushka are prevalent in many Eastern European countries. Anecdotal reports of its use have been circulating in Germany and Norway; however, this has not been confirmed. Its use has also been reported by the media in the USA, although only one confirmed report of its use exists. Home-produced drugs are associated with high levels of morbidity and a number of complex health issues such as the spread of blood borne viruses, gangrene, and internal organ damage. The high incidence of HIV rates amongst people who inject home-produced substances is a public health concern. The resulting physical health consequences of injecting these crude substances are very severe in comparison to heroin or amphetamine acquired in black markets. Due to this fact and the increased mortality associated with these substances, professionals in the area of prevention, treatment, and policy development need to be cognisant of the presentation, harms, and the dangers associated with home-produced substances globally. This scoping review aimed to examine existing literature on the subject of home-produced heroin and amphetamine-type stimulant substitutes. The review discussed the many implications such research may have in the areas of policy and practice. Data were gathered through the use of qualitative secondary resources such as journal articles, reports, reviews, case studies, and media reports. The home production of these substances relies on the utilisation of precursor drugs such as less potent stimulants, tranquillizers, analgesics, and sedatives or natural plant ingredients. The Internet underpins the facilitation of this practice as recipes, and diverted pharmaceutical sales are available widely online, and currently, ease of access to the Internet is evident worldwide. This review highlights the necessity of prevention, education, and also harm reduction related to home-produced drugs and also recommends consistent monitoring of online drug fora, online drug marketplaces, and unregulated pharmacies
Circulating mutational portrait of cancer: manifestation of aggressive clonal events in both early and late stages
Relevance of tumor-infiltrating lymphocytes in breast cancer
While breast cancer has not been considered a cancer amenable to immunotherapeutic approaches, recent studies have demonstrated evidence of significant immune cell infiltration via tumor-infiltrating lymphocytes in a subset of patient tumors. In this review we present the current evidence highlighting the clinical relevance and utility of tumor-infiltrating lymphocytes in breast cancer. Retrospective and prospective studies have shown that the presence of tumor-infiltrating lymphocytes is a prognostic marker for higher responses to neoadjuvant chemotherapy and better survival, particularly in triple negative and HER2-positive early breast cancer. Further work is required to determine the immune subsets important in this response and to discover ways of encouraging immune infiltrate in tumor-infiltrating lymphocytes-negative patients
Comparative effectiveness and cost-effectiveness of antiretroviral therapy and pre-exposure prophylaxis for HIV prevention in South Africa
Decomposition and the annual flux of detritus from fallen timber in tropical mangrove forests
Insightful analysis of carrier PWM algorithms for direct AC-AC matrix converter based on voltage-source converter modules
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