3,252 research outputs found
Icosahedral packing of polymer-tethered nanospheres and stabilization of the gyroid phase
We present results of molecular simulations that predict the phases formed by
the self-assembly of model nanospheres functionalized with a single polymer
"tether", including double gyroid, perforated lamella and crystalline bilayer
phases. We show that microphase separation of the immiscible tethers and
nanospheres causes confinement of the nanoparticles, which promotes local
icosahedral packing that stabilizes the gyroid and perforated lamella phases.
We present a new metric for determining the local arrangement of particles
based on spherical harmonic "fingerprints", which we use to quantify the extent
of icosahedral ordering.Comment: 8 pages, 4 figure
Development and validation of a risk score for hospitalization for heart failure in patients with Type 2 Diabetes Mellitus
<p>Abstract</p> <p>Background</p> <p>There are no risk scores available for predicting heart failure in Type 2 diabetes mellitus (T2DM). Based on the Hong Kong Diabetes Registry, this study aimed to develop and validate a risk score for predicting heart failure that needs hospitalisation in T2DM.</p> <p>Methods</p> <p>7067 Hong Kong Chinese diabetes patients without history of heart failure, and without history and clinical evidence of coronary heart disease at baseline were analyzed. The subjects have been followed up for a median period of 5.5 years. Data were randomly and evenly assigned to a training dataset and a test dataset. Sex-stratified Cox proportional hazard regression was used to obtain predictors of HF-related hospitalization in the training dataset. Calibration was assessed using Hosmer-Lemeshow test and discrimination was examined using the area under receiver's operating characteristic curve (aROC) in the test dataset.</p> <p>Results</p> <p>During the follow-up, 274 patients developed heart failure event/s that needed hospitalisation. Age, body mass index (BMI), spot urinary albumin to creatinine ratio (ACR), HbA<sub>1c</sub>, blood haemoglobin (Hb) at baseline and coronary heart disease during follow-up were predictors of HF-related hospitalization in the training dataset. HF-related hospitalization risk score = 0.0709 × age (year) + 0.0627 × BMI (kg/m<sup>2</sup>) + 0.1363 × HbA<sub>1c</sub>(%) + 0.9915 × Log<sub>10</sub>(1+ACR) (mg/mmol) - 0.3606 × Blood Hb(g/dL) + 0.8161 × CHD during follow-up (1 if yes). The 5-year probability of heart failure = 1-S<sub>0</sub>(5)<sup>EXP{0.9744 × (Risk Score - 2.3961)}</sup>. Where S<sub>0</sub>(5) = 0.9888 if male and 0.9809 if female. The predicted and observed 5-year probabilities of HF-related hospitalization were similar (p > 0.20) and the adjusted aROC was 0.920 for 5 years of follow-up.</p> <p>Conclusion</p> <p>The risk score had adequate performance. Further validations in other cohorts of patients with T2DM are needed before clinical use.</p
A Pilot Study Comparing HPV-Positive and HPV-Negative Head and Neck Squamous Cell Carcinomas by Whole Exome Sequencing.
Background. Next-generation sequencing of cancers has identified important therapeutic targets and biomarkers. The goal of this pilot study was to compare the genetic changes in a human papillomavirus- (HPV-)positive and an HPV-negative head and neck tumor. Methods. DNA was extracted from the blood and primary tumor of a patient with an HPV-positive tonsillar cancer and those of a patient with an HPV-negative oral tongue tumor. Exome enrichment was performed using the Agilent SureSelect All Exon Kit, followed by sequencing on the ABI SOLiD platform. Results. Exome sequencing revealed slightly more mutations in the HPV-negative tumor (73) in contrast to the HPV-positive tumor (58). Multiple mutations were noted in zinc finger genes (ZNF3, 10, 229, 470, 543, 616, 664, 638, 716, and 799) and mucin genes (MUC4, 6, 12, and 16). Mutations were noted in MUC12 in both tumors. Conclusions. HPV-positive HNSCC is distinct from HPV-negative disease in terms of evidence of viral infection, p16 status, and frequency of mutations. Next-generation sequencing has the potential to identify novel therapeutic targets and biomarkers in HNSCC
Impacts of chronic kidney disease and albuminuria on associations between coronary heart disease and its traditional risk factors in type 2 diabetic patients – the Hong Kong diabetes registry
<p>Abstract</p> <p>Background</p> <p>Glycated haemoglobin (HbA<sub>1c</sub>), blood pressure and body mass index (BMI) are risk factors for albuminuria, the latter in turn can lead to hyperlipidaemia. We used novel statistical analyses to examine how albuminuria and chronic kidney disease (CKD) may influence the effects of other risk factors on coronary heart disease (CHD).</p> <p>Methods</p> <p>A prospective cohort of 7067 Chinese type 2 diabetic patients without history of CHD enrolled since 1995 were censored on July 30<sup>th</sup>, 2005. Cox proportional hazard regression with restricted cubic spline was used to auto-select predictors. Hazard ratio plots were used to examine the risk of CHD. Based on these plots, non-linear risk factors were categorised and the categorised variables were refitted into various Cox models in a stepwise manner to confirm the findings.</p> <p>Results</p> <p>Age, male gender, duration of diabetes, spot urinary albumin: creatinine ratio, estimated glomerular filtration rate, total cholesterol (TC), high density lipoprotein cholesterol (HDL-C) and current smoking status were risk factors of CHD. Linear association between TC and CHD was observed only in patients with albuminuria. Although in general, increased HDL-C was associated with decreased risk of CHD, full-range HDL-C was associated with CHD in an A-shaped manner with a zenith at 1.1 mmol/L. Albuminuria and CKD were the main contributors for the paradoxically positive association between HDL-C and CHD for HDL-C values less than 1.1 mmol/L.</p> <p>Conclusion</p> <p>In type 2 diabetes, albuminuria plays a linking role between conventional risk factors and CHD. The onset of CKD changes risk associations between lipids and CHD.</p
Ad hoc influenza vaccination during years of significant antigenic drift in a tropical city with 2 seasonal peaks
We evaluated the acceptability of an additional ad hoc influenza vaccination among the health care professionals following seasons with significant antigenic drift. Self-administered, anonymous surveys were performed by hard copy questionnaires in public hospitals, and by an on-line platform available to all healthcare professionals, from April 1st to May 31st, 2015. A total of 1290 healthcare professionals completed the questionnaires, including doctors, nurses, and allied health professionals working in both the public and private systems. Only 31.8% of participating respondents expressed an intention to receive the additional vaccine, despite that the majority of them agreed or strongly agreed that it would bring benefit to the community (88.9%), save lives (86.7%), reduce medical expenses (76.3%), satisfy public expectation (82.8%), and increase awareness of vaccination (86.1%). However, a significant proportion expressed concern that the vaccine could disturb the normal immunization schedule (45.5%); felt uncertain what to do in the next vaccination round (66.0%); perceived that the summer peak might not occur (48.2%); and believed that the summer peak might not be of the same virus (83.5%). Furthermore, 27.8% of all respondents expected that the additional vaccination could weaken the efficacy of previous vaccinations; 51.3% was concerned about side effects; and 61.3% estimated that there would be a low uptake rate. If the supply of vaccine was limited, higher priority groups were considered to include the elderly aged ≥65 years with chronic medical conditions (89.2%), the elderly living in residential care homes (87.4%), and long-stay residents of institutions for the disabled (80.7%). The strongest factors associated with accepting the additional vaccine included immunization with influenza vaccines in the past 3 years, higher perceived risk of contracting influenza, and higher perceived severity of the disease impact. The acceptability to an additional ad hoc influenza vaccination was low among healthcare professionals. This could have a negative impact on such additional vaccination campaigns since healthcare professionals are a key driver for vaccine acceptance. The discordance in perceived risk and acceptance of vaccination regarding self versus public deserves further evaluation
Recommended from our members
kb_DRAM: annotation and metabolic profiling of genomes with DRAM in KBase
Microbial genome annotation is the process of identifying structural and functional elements in DNA sequences and subsequently attaching biological information to those elements. DRAM is a tool developed to annotate bacterial, archaeal, and viral genomes derived from pure cultures or metagenomes. DRAM goes beyond traditional annotation tools by distilling multiple gene annotations to genome level summaries of functional potential. Despite these benefits, a downside of DRAM is the requirement of large computational resources, which limits its accessibility. Further, it did not integrate with downstream metabolic modeling tools that require genome annotation. To alleviate these constraints, DRAM and the viral counterpart, DRAM-v, are now available and integrated with the freely accessible KBase cyberinfrastructure. With kb_DRAM users can generate DRAM annotations and functional summaries from microbial or viral genomes in a point-and-click interface, as well as generate genome-scale metabolic models from DRAM annotations.Availability and implementationFor kb_DRAM users, the kb_DRAM apps on KBase can be found in the catalog at https://narrative.kbase.us/#catalog/modules/kb_DRAM. For kb_DRAM users, a tutorial workflow with all documentation is available at https://narrative.kbase.us/narrative/129480. For kb_DRAM developers, software is available at https://github.com/shafferm/kb_DRAM
Association of Body Mass Index and Extreme Obesity With Long-Term Outcomes Following Percutaneous Coronary Intervention
Background:
Previous studies have reported a protective effect of obesity compared with normal body mass index (BMI) in patients undergoing percutaneous coronary intervention (PCI). However, it is unclear whether this effect extends to the extremely obese. In this large multicenter registry‐based study, we sought to examine the relationship between BMI and long‐term clinical outcomes following PCI, and in particular to evaluate the association between extreme obesity and long‐term survival after PCI.
Methods and Results:
This cohort study included 25 413 patients who underwent PCI between January 1, 2005 and June 30, 2017, who were prospectively enrolled in the Melbourne Interventional Group registry. Patients were stratified by World Health Organization–defined BMI categories. The primary end point was National Death Index–linked mortality. The median length of follow‐up was 4.4 years (interquartile range 2.0‐7.6 years). Of the study cohort, 24.8% had normal BMI (18.5‐24.9 kg/m2), and 3.3% were extremely obese (BMI ≥40 kg/m2). Patients with greater degrees of obesity were younger and included a higher proportion of diabetics (P<0.001). After adjustment for age and comorbidities, a J‐shaped association was observed between different BMI categories and adjusted hazard ratio (HR) for long‐term mortality (normal BMI, HR 1.00 [ref]; overweight, HR 0.85, 95% CI 0.78‐0.93, P<0.001; mild obesity, HR 0.85, 95% CI 0.76‐0.94, P=0.002; moderate obesity, HR 0.95, 95% CI 0.80‐1.12, P=0.54; extreme obesity HR 1.33, 95% CI 1.07‐1.65, P=0.01).
Conclusions:
An obesity paradox is still apparent in contemporary practice, with elevated BMI up to 35 kg/m2 associated with reduced long‐term mortality after PCI. However, this protective effect appears not to extend to patients with extreme obesity
Intermolecular CT excitons enable nanosecond excited-state lifetimes in NIR-absorbing non-fullerene acceptors for efficient organic solar cells
State-of-the-art Y6-type molecular acceptors exhibit nanosecond excited-state
lifetimes despite their low optical gaps (~1.4 eV), thus allowing organic solar
cells (OSCs) to achieve highly efficient charge generation with extended
near-infrared (NIR) absorption range (up to ~1000 nm). However, the precise
molecular-level mechanism that enables low-energy excited states in Y6-type
acceptors to achieve nanosecond lifetimes has remained elusive. Here, we
demonstrate that the distinct packing of Y6 molecules in film leads to a strong
intermolecular charge-transfer (iCT) character of the lowest excited state in
Y6 aggregates, which is absent in other low-gap acceptors such as ITIC. Due to
strong electronic couplings between the adjacent Y6 molecules, the iCT-exciton
energies are greatly reduced by up to ~0.25 eV with respect to excitons formed
in separated molecules. Importantly, despite their low energies, the iCT
excitons have reduced non-adiabatic electron-vibration couplings with the
electronic ground state, thus suppressing non-radiative recombination and
allowing Y6 to overcome the well-known energy gap law. Our results reveal the
fundamental relationship between molecular packing and nanosecond excited-state
lifetimes in NIR-absorbing Y6-type acceptors underlying the outstanding
performance of Y6-based OSCs
Room-temperature InP/InGaAs nano-ridge lasers grown on Si and emitting at telecom bands
Semiconductor nano-lasers grown on silicon and emitting at the telecom bands are advantageous ultra-compact coherent light sources for potential Si-based photonic integrated circuit applications. However, realizing room-temperature lasing inside nano-cavities at telecom bands is challenging and has only been demonstrated up to the E band. Here, we report on InP/InGaAs nano-ridge lasers with emission wavelengths ranging from the O, E, and S bands to the C band operating at room temperature with ultra-low lasing thresholds. Using a cycled growth procedure, ridge InGaAs quantum wells inside InP nano-ridges grown on patterned (001) Si substrates are designed as active gain materials. Room-temperature lasing at the telecom bands is achieved by transferring the InP/InGaAs nano-ridges onto a SiO2∕Si substrate for optical excitation. We also show that the operation wavelength of InP/InGaAs nano-lasers can be adjusted by altering the excitation power density and the length of the nano-ridges formed in a single growth run. These results indicate the excellent optical properties of the InP/InGaAs nano-ridges grown on (001) Si substrates and pave the way towards telecom InP/InGaAs nano-laser arrays on CMOS standard Si or silicon-on-insulator substrates
- …