To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
The ability to prcbe the structure of a polymer during deformation is of considerable technological interest as it lends an insight into the mechanisms involved in polymer processing. The behaviour of Liquid Crystalline Polymers (LCP's) during shear flow has generated much experimental interest by virtue of their unusual behaviour compared to that of simpler polymeric melts. The theory developed by Doi attempts to explain the observed phenomena in terms of considering interactions of rigid-rods Exact solutions to the Doi theory have been compared to experimental procedures using lyotropic LCP systems. Although much of the available data relates to mechanical measurements, the comparisons with quantitative structural data can provide useful insight.
Keratins are the main structural proteins of wool fibres, and it is thought that variation in the keratins may affect wool fibre characteristics. Polymerase chain reaction-single stranded conformational polymorphism (PCR-SSCP) analyses were used to investigate four regions of the ovine keratin gene KRT31 including a portion of the promoter, the exon 1, exon 3 and exon 7 regions. Initially, in a screening panel of 300 New Zealand Romney, Merino and White Dorper sheep obtained from 26 farms, three, two, two and two PCR-SSCP banding patterns were observed for these four regions, respectively. The promoter region, the exon 1 and exon 3 regions contained two single nucleotide polymorphisms (SNPs) and the exon 7 region contained one SNP. The effect of the variation found in the promoter region on wool traits was subsequently investigated in 485 Southdown × Merino-cross lambs from seven sire-lines. The three variants identified in the original 300 sheep (named A, B and C) were observed with frequencies of 56, 29 and 15%, respectively. The presence of A and B had no significant effect on wool traits, but the presence of C was found to be associated with an increase in greasy fleece weight (GFW), clean fleece weight (CFW) and mean staple length (MSL). There was an effect of genotype on CFW and MSL, with BC sheep producing wool of higher CFW and MSL than AA, AB, AC and BB sheep. These results suggest that ovine KRT31 might be a useful candidate gene for improving wool traits.
Little is known about the combined use of benzodiazepines and antidepressants in older psychiatric patients. This study examined the prescription pattern of concurrent benzodiazepines in older adults treated with antidepressants in Asia, and explored its demographic and clinical correlates.
The data of 955 older adults with any type of psychiatric disorders were extracted from the database of the Research on Asian Psychotropic Prescription Patterns for Antidepressants (REAP-AD) project. Demographic and clinical characteristics were recorded using a standardized protocol and data collection procedure. Both univariate and multiple logistic regression analyses were performed.
The proportion of benzodiazepine and antidepressant combination in this cohort was 44.3%. Multiple logistic regression analysis revealed that higher doses of antidepressants, younger age (<65 years), inpatients, public hospital, major comorbid medical conditions, antidepressant types, and country/territory were significantly associated with more frequent co-prescription of benzodiazepines and antidepressants.
Nearly, half of the older adults treated with antidepressants in Asia are prescribed concurrent benzodiazepines. Given the potentially adverse effects of benzodiazepines, the rationale of benzodiazepines and antidepressants co-prescription needs to be revisited.
Previous findings have been mixed regarding the relationship between maternal depressive symptoms and child cognitive development. The objective of this study was to systematically review relevant literature and to perform a meta-analysis.
Three electronic databases (PubMed, EMBASE, PsycINFO) were searched. Initial screening was conducted independently by two reviewers. Studies selected for detailed review were read in full and included based on a set of criteria. Data from selected studies were abstracted onto a standardized form. Meta-analysis using the inverse variance approach and random-effects models was conducted.
The univariate analysis of 14 studies revealed that maternal depressive symptoms are related to lower cognitive scores among children aged ⩽56 months (Cohen's d = −0.25, 95% CI −0.39 to −0.12). The synthesis of studies controlling for confounding variables showed that the mean cognitive score for children 6–8 weeks post-partum whose mothers had high depressive symptoms during the first few weeks postpartum was approximately 4.2 units lower on the Mental Developmental Index (MDI) of the Bayley Scales of Infant and Toddler Development (BSID) compared with children with non-symptomatic mothers (B̂ = −4.17, 95% CI −8.01 to −0.32).
The results indicated that maternal depressive symptoms are related to lower cognitive scores in early infancy, after adjusting for confounding factors. An integrated approach for supporting child cognitive development may include program efforts that promote maternal mental health in addition to family economic wellbeing, responsive caregiving, and child nutrition.
As poultry consumption continues to increase worldwide, and as the United States accounts for about one-third of all poultry exports globally, understanding factors leading to poultry-associated foodborne outbreaks in the United States has important implications for food safety. We analysed outbreaks reported to the United States’ Foodborne Disease Outbreak Surveillance System from 1998 to 2012 in which the implicated food or ingredient could be assigned to one food category. Of 1114 outbreaks, poultry was associated with 279 (25%), accounting for the highest number of outbreaks, illnesses, and hospitalizations, and the second highest number of deaths. Of the 149 poultry-associated outbreaks caused by a confirmed pathogen, Salmonella enterica (43%) and Clostridium perfringens (26%) were the most common pathogens. Restaurants were the most commonly reported location of food preparation (37% of poultry-associated outbreaks), followed by private homes (25%), and catering facilities (13%). The most commonly reported factors contributing to poultry-associated outbreaks were food-handling errors (64%) and inadequate cooking (53%). Effective measures to reduce poultry contamination, promote safe food-handling practices, and ensure food handlers do not work while ill could reduce poultry-associated outbreaks and illnesses.
Non-alcoholic fatty liver disease (NAFLD) is significantly associated with hyperlipidaemia and oxidative stress. We have previously reported that astaxanthin (ASTX), a xanthophyll carotenoid, lowers plasma total cholesterol and TAG concentrations in apoE knockout mice. To investigate whether ASTX supplementation can prevent the development of NAFLD in obesity, male C57BL/6J mice (n 8 per group) were fed a high-fat diet (35 %, w/w) supplemented with 0, 0·003, 0·01 or 0·03 % of ASTX (w/w) for 12 weeks. The 0·03 % ASTX-supplemented group, but not the other groups, exhibited a significant decrease in plasma TAG concentrations, suggesting that ASTX at a 0·03 % supplementation dosage exerts a hypotriacylglycerolaemic effect. Although there was an increase in the mRNA expression of fatty acid synthase and diglyceride acyltransferase 2, the mRNA levels of acyl-CoA oxidase 1, a critical enzyme in peroxisomal fatty acid β-oxidation, exhibited an increase in the 0·03 % ASTX-supplemented group. There was a decrease in plasma alanine transaminase (ALT) and aspartate transaminase (AST) concentrations in the 0·03 % ASTX-supplemented group. There was a significant increase in the hepatic mRNA expression of nuclear factor erythroid 2-related factor 2 and its downstream genes, which are critical for endogenous antioxidant mechanism, in the 0·03 % ASTX-supplemented group. Furthermore, there was a significant decrease in the mRNA abundance of IL-6 in the primary splenocytes isolated from the 0·03 % ASTX-supplemented group upon lipopolysaccharide (LPS) stimulation when compared with that in the splenocytes isolated from the control group. In conclusion, ASTX supplementation lowered the plasma concentrations of TAG, ALT and AST, increased the hepatic expression of endogenous antioxidant genes, and rendered splenocytes less sensitive to LPS stimulation. Therefore, ASTX may prevent obesity-associated metabolic disturbances and inflammation.
We compared the epidemiological and clinical features of avian influenza A(H7N9) virus infections in the population in Zhejiang province, China, between March and April 2013 (first wave) and October 2013 and February 2014 (second wave). No statistical difference was found for age, sex, occupation, presence of underlying conditions, exposure history, white blood cell count, lymphocyte percentage and illness timeline and duration (all P > 0·05). The virus spread to 30 new counties compared to the first wave. The case-fatality rate was 22% in the first wave and 42% in the second (P = 0·023). Of those infected, 66% in the first wave and 62% in the second wave had underlying conditions. The proportion of those exposed to live poultry markets were 80% and 66%, respectively. We recommend permanent closure of live poultry markets and reformation of poultry supply and sales.
Severe fever with thrombocytopenia syndrome virus (SFTSV) has been prevalent for some time in China and it was first identified in 2010. However, the seroprevalence of SFTSV in the general population in southeastern China and risk factors associated with the infection are currently unclear. Blood samples were collected from seven counties across Zhejiang province and tested for the presence of SFTSV-specific IgG antibodies by ELISA. A total of 1380 blood samples were collected of which 5·51% were seropositive for SFTSV with seroprevalence varying significantly between sites. Seroprevalence of SFTSV in people who were family members of the patient, lived in the same village as the patient, or lived in a different village than the patient varied significantly. There was significant difference in seroprevalence between participants who bred domestic animals and participants who did not. Domestic animals are probably potential reservoir hosts and contact with domestic animals may be a transmission route of SFTSV.
To evaluate the presence of a new type of reovirus (designated R4) in humans, we determined the prevalence of specific antibodies using a neutralization assay and ELISA. The sera from 97 healthy people and 219 patients in our hospital with measles, hand-foot-and-mouth disease, liver diseases, and diarrhoea were investigated. Although the study population was limited, our data suggested that R4 is widespread in the human population. A significantly higher level of R4-specific antibody in patients than in healthy people is worthy of consideration, since it poses a risk for aggravation of the extant illness by the reovirus.
Tetralogy of Fallot is the most common cyanotic heart defect seen in children beyond infancy. There is considerable variation in surgical management today ranging from differences in timing of complete repair versus initial use of a shunt for palliation, and methods for right ventricular outflow tract reconstruction. This article will examine some of the current surgical management techniques for patients with Tetralogy of Fallot.
A large area nanogap electrode fabrication method combinig conventional lithography patterning with the of focused ion beam (FIB) is presented. Lithography and a lift-off process were used to pattern 50 nm thick platinum pads having an area of 300 μm × 300 μm. A range of 30-300 nm wide nanogaps (length from 300 μm to 10 mm ) were then etched using an FIB of Ga+ at an acceleration voltage of 30 kV at various beam currents. An investigation of Ga+ beam current ranging between 1-50 pA was undertaken to optimise the process for the current fabrication method. In this study, we used Monte Carlo simulation to calculate the damage depth in various materials by the Ga+. Calculation of the recoil cascades of the substrate atoms are also presented. The nanogap electrodes fabricated in this study were found to have empty gap resistances exceeding several hundred MΩ. A comparison of the gap length versus electrical resistance on glass substrates is presented. The results thus outline some important issues in low-conductance measurements. The proposed nanogap fabrication method can be extended to various sensor applications, such as chemical sensing, that employ the nanogap platform. This method may be used as a prototype technique for large-scale fabrication due to its simple, fast and reliable features.
Surgery for common arterial trunk has evolved over the past 30 years. Current management involves total repair during the neonatal period with excellent expected results. The presence of truncal valve insufficiency or interrupted aortic arch may increase the surgical risk for morbidity and mortality. Current therapy and management continues to evolve.
Relief of right ventricular outflow tract obstruction in tetralogy of Fallot or similar physiology often results in pulmonary regurgitation. The resultant chronic volume overload can lead to right ventricular dilatation, biventricular dysfunction, heart failure symptoms, arrhythmias, and sudden death. Although pulmonary valve replacement can lead to improvement in functional class and a substantial decrease or normalisation of right ventricular volumes, the optimal timing of pulmonary valve replacement is not well defined. Benefits of pulmonary valve replacement have to be weighed against the risks of this procedure, including subsequent reoperation. This article will review the benefits and risks of pulmonary valve replacement, options for pulmonary valve substitute, and timing of pulmonary valve replacement in patients with chronic pulmonary regurgitation after relief of right ventricular outflow tract obstruction.
Extracorporeal cardiopulmonary resuscitation may be defined as the use of extracorporeal membrane oxygenation for the support of patients who do not respond to conventional cardiopulmonary resuscitation. Data from national and international paediatric databases indicate that the use of extracorporeal cardiopulmonary resuscitation is increasing. Guidelines from the American Heart Association suggest that any patient with refractory cardiopulmonary resuscitation and potentially reversible causes of cardiac arrest is a candidate for extracorporeal cardiopulmonary resuscitation. One possible framework for selection of patients for extracorporeal cardiopulmonary resuscitation includes dividing patients on the basis of favourable or unfavourable characteristics. Favourable characteristics include cardiac disease, witnessed event in the intensive care unit, ability to deliver effective cardiopulmonary resuscitation, active patient monitoring present, favourable arterial blood gases, and early institution of extracorporeal membrane oxygenation. Unfavourable characteristics potentially include non-cardiac disease, an unwitnessed cardiac arrest, ineffective cardiopulmonary resuscitation, and severely acidotic arterial blood gases. Considering the significant resources and cost involved in the use of extracorporeal cardiopulmonary resuscitation, its use needs to be critically examined to improve outcomes, assess neurological recovery and quality of life, and help identify populations and other factors that may help guide in the selection of patients for successful extracorporeal cardiopulmonary resuscitation.
The use of extracorporeal membrane oxygenation in infants and children with cardiac disease who develop refractory cardiogenic shock, cyanosis, or cardiac arrest is increasing. Early mortality in children with cardiac disease who require extracorporeal membrane oxygenation remains an important issue, as only 40% of cannulated patients survive to discharge from the hospital. However, it is encouraging that 90% children who are discharged alive from the hospital after extracorporeal membrane oxygenation are still alive at intermediate-term follow-up. Surviving patients are at risk for long-term dysfunction of multiple organ systems related to their underlying cardiac disease, non-cardiac comorbidities, treatment-related complications, and exposure to extracorporeal membrane oxygenation. Among the most important acute complications related to support with extracorporeal membrane oxygenation is injury to the central nervous system, which may contribute to adverse neurodevelopmental outcomes. All of these factors, in turn, influence quality of life. Many survivors remain medically complex related to their underlying cardiac disease, comorbidities, and sequelae of complications acquired over their lifetime. Neurological morbidity clearly plays an important role in approximately one-third of survivors, with significant deficits in approximately 10%. The limited data about quality of life data that are available for survivors of cardiac extracorporeal membrane oxygenation suggests that approximately 15–30% of survivors have at least moderately decreased quality of life. Overall, published data support the ongoing use of support with extracorporeal membrane oxygenation in children with acute cardiac failure, most of whom would die without it. However, programmatic efforts to improve the selection of patients and the preservation of the function of end organs during extracorporeal membrane oxygenation are clearly needed in order to improve long-term outcomes.
The aortic pulse wave velocity (PWV) is a useful clinical index to assess the aortic compliance and cardiovascular risk in a noninvasive manner. In this research, our previously developed axial velocity profile method (Yu et al., ) was modified to be more user-friendly and applied to the study of PWV of diabetic patients for the first time, using phase-contrast magnetic resonance imaging (PC-MRI) technique to analyze the spatial and temporal profiles of the axial velocity along the descending aorta for measurement of the aortic PWV. The PWV results from healthy volunteers and diabetic patients were studied and compared. It is shown that the PWV of diabetic patients is much higher than that of health volunteers, the aortic compliance of diabetic patients is substantially worse than that of health volunteers. These results are in good agreement with early studies using different measurement techniques of PWV. The axial velocity profile method is again validated and proven to be a useful tool of long-term prognosis for patients with diabetes mellitus or hypertension.
To identify patient-care practices related to an increased prevalence of hepatitis C virus (HCV) infection among chronic hemodialysis patients.
Chronic hemodialysis facilities in the United States.
Equal-probability 2-stage cluster sampling was used to select 87 facilities from all Medicare-approved providers treating 30–150 patients; 53 facilities and 2,933 of 3,680 eligible patients agreed to participate.
Patients were tested for HCV antibody and HCV RNA. Data on patient-care practices were collected using direct observation.
The overall prevalence of HCV infection was 9.9% (95% confidence interval [CI], 8.2%–11.6%); only 2 of 294 HCV-positive patients were detected solely by HCV RNA testing. After adjusting for non-dialysis-related HCV risk factors, patient-care practices independently associated with a higher prevalence of HCV infection included reusing priming receptacles without disinfection (odds ratio [OR], 2.3 [95% CI, 1.4–3.9]), handling blood specimens adjacent to medications and clean supplies (OR, 2.2 [95% CI, 1.3–3.6]), and using mobile carts to deliver injectable medications (OR, 1.7 [95% CI, 1.0–2.8]). Independently related facility covariates were at least 10% patient HCV infection prevalence (OR, 3.0 [95% CI, 1.8–5.2]), patient-to-staff ratio of at least 7: 1 (OR, 2.4 [95% CI, 1.4–4.1]), and treatment duration of at least 2 years (OR, 2.4 [95% CI, 1.3–4.4]).
This study provides the first epidemiologic evidence of associations between specific patient-care practices and higher HCV infection prevalence among hemodialysis patients. Staff should review practices to ensure that hemodialysis-specific infection control practices are being implemented, especially handling clean and contaminated items in separate areas, reusing items only if disinfected, and prohibiting mobile medication and clean supply carts within treatment areas.
Tantalum (Ta) thin films of 35 nm thickness were investigated as diffusion barriers as well as adhesion-promoting layers between Cu and SiO2 using X-ray diffractometry (XRD), Scanning electron microscopy (SEM), Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). After annealing at 600°C for 1h in vacuum, no evidence of interdiffusion was observed. However, XPS depth profiling indicates that elemental Si appears at the Ta/SiO2 interface after annealing. In-situ XPS studies show that the Ta/SiO2 interface was stable until 500°C, but about 32% of the interfacial SiO2 was reduced to elemental Si at 600°C. Upon cooling to room temperature, some elemental Si recombined to form SiO2 again, leaving only 6.5% elemental Si. Comparative studies on the interface chemical states of Cu/SiO2 and Ta/SiO2 indicate that the stability of the Cu/Ta/SiO2/Si system may be ascribed to the strong bonding of Ta and SiO2, due to the reduction of SiO2 through Ta oxide formation.
Generation of C60 at a rate of more than 10 grams per day has been accomplished by operation of a carbon arc in an atmosphere of helium. Optimum yield of 15% was found to occur near 100–200 torr, but yields greater than 3% were found throughout the range between 50 and 760 torr. A model is proposed to explain the observed behavior based on competition between annealing of graphitic sheets to curve so that they minimize dangling bonds, and further rapid growth of these sheets in the gas phase to form giant fullerenes. In agreement with predictions of this model, laser vaporization of graphite targets was found to produce macroscopic quantities of C60 only when performed in an oven above 1000 C.