9,986 research outputs found
Line shifts in the first overtone of DF broadened by HF
Line spectra shifts in HF and in first overtone band of DF induced by HF pressure
Evolution of the Phoenix EDL System Architecture
This viewgraph presentation gives a general overview of the Phoenix spacecraft evolution, entry, descent, landing and system architecture
Crystal Structures of Influenza A Virus Matrix Protein M1: Variations on a Theme
Matrix protein 1 (M1) of the influenza A virus plays multiple roles in virion assembly and infection. Interest in the pH dependence of M1\u27s multiple functions led us to study the effect of subtle pH changes on M1 structure, resulting in the elucidation of a unique low-pH crystal structure of the N1-165-domain of A/WSN/33 (H1N1) M1 that has never been reported. Although the 2.2 Å crystal structure of M1 N-terminus shows a dimer with the two monomers interacting in a face-to-face fashion at low pH as observed earlier, a 44° rotation of the second monomer has led to a significantly different dimer interface that possibly affects dimer stability. More importantly, while one of the monomers is fully defined, the N-terminal half of the second monomer shows considerable disorder that appears inherent in the protein and is potentially physiologically relevant. Such disorder has not been observed in any other previously reported structure at either low or high pH conditions, despite similar crystallization pH conditions. By comparing our novel N1-165-domain structure with other low-pH or neutral-pH M1 structures, it appears that M1 can energetically access different monomer and dimer conformations, as well as oligomeric states, with varying degree of similarities. The study reported here provides further insights into M1 oligomerization that may be essential for viral propagation and infectivity
Genetic risk for Huntington Disease and reproductive decision-making: A systematic review
Huntington Disease (HD) is an incurable autosomal dominant single gene neurodegenerative disorder. Typical onset is between 30 and 40 years and characterised by motor difficulties, cognitive impairment, and behavioural and personality changes. The availability of reproductive testing means that affected and at-risk individuals can make reproductive decisions with genetic risk in mind. We aimed to summarise the literature on reproductive decision-making in the context of HD risk in terms of outcomes and the subjective experiences of at-risk individuals. Five databases were searched. Findings were synthesised using Framework analysis to identify common factors across results of quantitative and qualitative studies. Twenty five studies met inclusion criteria. Framework analysis identified the following key areas: ‘The relationship between reproductive intentions and HD genetic risk’, ‘Views on assistive options’, ‘Complexity and challenges in reproductive decision-making’, ‘Actual reproductive outcomes’, and ‘Other factors influencing reproductive decision-making’. Quality of included studies was mixed. Reproductive decision making in the context of HD risk was found to be a complex and emotionally challenging process. Further research is required into reproductive decision-making and outcomes among those not utilising assistive options, and in developing a model of reproductive decision-making in HD
Pairwise Balanced Designs From Cyclic PBIB Designs
A pairwise balanced designs was constructed using cyclic partially balanced incomplete block designs with either (λ1 – λ2) = 1 or (λ2 – λ1) = 1. This method of construction of Pairwise balanced designs is further generalized to construct it using cyclic partially balanced incomplete block design when |(λ1 – λ2)| = p. The methods of construction of pairwise balanced designs was supported with examples. A table consisting parameters of Cyclic PBIB designs and its corresponding constructed pairwise balanced design is also included
Recent advances in pre-exposure prophylaxis for HIV
Although pre-exposure prophylaxis (PrEP)-the use of antiretroviral drugs by non-infected people to prevent the acquisition of HIV-is a promising preventive option, important public health questions remain. Daily oral emtricitabine (FTC)-tenofovir disoproxil fumarate (TDF) is highly efficacious in preventing the acquisition of HIV in people at risk as a result of a range of different types of sexual exposure. There is good evidence of efficacy in women and men, and when men who have sex with men use event based dosing. Studies have been conducted in several countries and epidemics. Because adherence to this treatment varies greatly there are questions about its public health benefit. Oral FTC-TDF is extremely safe, with minimal impact on kidney, bone, or pregnancy outcomes, and there is no evidence that its effectiveness has been reduced by risk compensation during open label and programmatic follow-up. It is too early to assess the impact of this treatment on the incidence of sexually transmitted infections (STIs) at a population level. Many challenges remain. Access to pre-exposure prophylaxis is limited and disparities exist, including those governed by race and sex. Different pricing and access models need to be explored to avoid further widening inequalities. The optimal combination prevention program needs to be defined, and this will depend on local epidemiology, service provision, and cost effectiveness. This review updates the evidence base for pre-exposure prophylaxis regarding its effectiveness, safety, and risk compensation
Stellar Mass to Halo Mass Scaling Relation for X-ray Selected Low Mass Galaxy Clusters and Groups out to Redshift
We present the stellar mass-halo mass scaling relation for 46 X-ray selected
low-mass clusters or groups detected in the XMM-BCS survey with masses
at
redshift . The cluster binding masses are inferred
from the measured X-ray luminosities \Lx, while the stellar masses
of the galaxy populations are estimated using near-infrared imaging from the
SSDF survey and optical imaging from the BCS survey. With the measured \Lx\ and
stellar mass , we determine the best fit stellar mass-halo mass
relation, accounting for selection effects, measurement uncertainties and the
intrinsic scatter in the scaling relation. The resulting mass trend is
, the intrinsic (log-normal) scatter is
, and there is no
significant redshift trend , although
the uncertainties are still large. We also examine within a fixed
projected radius of ~Mpc, showing that it provides a cluster binding mass
proxy with intrinsic scatter of (1 in ). We
compare our scaling relation from the XMM-BCS
clusters with samples of massive, SZE-selected clusters
() and low mass NIR-selected clusters
() at redshift .
After correcting for the known mass measurement systematics in the compared
samples, we find that the scaling relation is in good agreement with the high
redshift samples, suggesting that for both groups and clusters the stellar
content of the galaxy populations within depends strongly on mass but
only weakly on redshift out to .Comment: 15 pages, 10 figures. Accepted for publication in MNRA
Can We Do Away With PTBD?
Percutaneous Transhepatic Biliary Drainage (PTBD) is performed in surgical jaundice to
decompress the biliary tree and improve hepatic functions. However, the risk of sepsis is high
in these patients due to immunosuppression and surgical outcome remains poor. This raises a
question—can we do away with PTBD? To answer this query a study was carried out in 4
groups of patients bearing in mind the high incidence of sepsis and our earlier studies, which
have demonstrated immunotherapeutic potential of Tinospora cordifolia (TC): (A) those
undergoing surgery without PTBD (n = 14), (B) those undergoing surgery after PTBD
(n = 13). The mortality was 57.14% in Group A as compared to 61.54% in Group B. Serial
estimations of bilirubin levels carried out during the course of drainage (3 Wks) revealed a
gradual and significant decrease from 12.52 ± 8.3 mg% to 5.85 ± 3.0 mg%. Antipyrine half-life
did not change significantly (18.35 ± 4.2 hrs compared to basal values 21.96 ± 3.78 hrs). The
phagocytic and intracellular killing (ICK) capacities of PMN remained suppressed (Basal:
22.13 ± 3.68% phago, and 19.1 ± 4.49% ICK; Post drainage: 20 ± 8.48% Phago and 11.15 ± 3.05% ICK). Thus PTBD did not improve the metabolic capacity ofthe liver and mortality was
higher due to sepsis. Group (C) patientg received TC during PTBD (n = 16) and Group (D)
patients received TC without PTBD (n = 14). A significant improvement in PMN functions
occurred by 3 weeks in both groups (30.29 ± 4.68% phago, 30 ± 4.84% ICK in Group C and
30.4 ± 2.99% phago, 27.15 ± 6.19% ICK in Group D). The mortality in Groups C and D was
25% and 14.2% respectively during the preoperative period. There was no mortality after
surgery. It appears from this study that host defenses as reflected by PMN functions play an
important role in influencing prognosis. Further decompression of the biliary tree by PTBD
seems unwarranted
Plasma induced nano-finish for multifunctional properties on cotton fabric
Atmospheric pressure dielectric barrier discharge plasma treatment for fabric surface activation to facilitate deposition of nano silicon oxide, and nano-titanium dioxide onto cotton fabric has been studied. It is aimed to study the possibility of engineering a multifunctional cotton fabric. The treated fabric is evaluated for ultraviolet protection factor (UPF), antimicrobial activity, and flame retardancy as a functional finish. Surface morphology (SEM), thermo-gravimetric analysis (TGA), and mechanical properties are also studied. Scanning electron microscopy shows deposition of nano particles onto the fabric. He-O2 plasma pre-treatment improves the flame retardancy, UPF, antibacterial activity and thermal stability of the samples as compared to untreated samples. In order to improve the wash fastness of the finish, HMDSO plasma polymer is deposited on the surface of the finished fabric which acts as a barrier layer and imparts durable finish on cotton textiles.
Immunohistochemical evidence of tissue hypoxia and astrogliosis in the rostral ventrolateral medulla of spontaneously hypertensive rats
Increased activity of the sympathetic nervous system has been highlighted as a key factor that contributes to the development and maintenance of arterial hypertension. However, the factors that precipitate sustained increases in sympathetic activity remain poorly understood. Resting tissue oxygen partial pressure (PtO2) in the brainstem of anesthetized spontaneously hypertensive rats (SHRs) has been shown to be lower than in normotensive rats despite normal levels of arterial PO2. A hypoxic environment in the brainstem has been postulated to activate astroglial signalling mechanisms in the rostral ventrolateral medulla (RVLM) which in turn increase the excitability of presympathetic neuronal networks. In this study, we assessed the expression of indirect markers of tissue hypoxia and astroglial cell activation in the RVLM of SHRs and age-matched normotensive Wistar rats. Immunohistochemical labelling for hypoxia-induced factor-1α (HIF-1α) and bound pimonidazole adducts revealed the presence of tissue hypoxia in the RVLM of SHRs. Double immunostaining showed co-localization of bound pimonidazole labelling in putative presympathetic C1 neurons and in astroglial cells. Quantification of glial fibrillary acidic protein (GFAP) immunofluorescence showed relatively higher number of astrocytes and increased GFAP mean grey value density, whilst semi-quantitative analysis of skeletonized GFAP-immunoreactive processes revealed greater % area covered by astrocytic processes in the RVLM of adult SHRs. In conclusion, the morphological findings of tissue hypoxia and astrogliosis within brainstem presympathetic neuronal networks in the SHR support previous observations, showing that low brainstem PtO2 and increased astroglial signalling in the RVLM play an important role in pathological sympathoexcitation associated with the development of arterial hypertension
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