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 email@example.com
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.
An acute gastroenteritis (AGE) outbreak caused by a norovirus occurred at a hospital in Shanghai, China, was studied for molecular epidemiology, host susceptibility and serological roles. Rectal and environmental swabs, paired serum samples and saliva specimens were collected. Pathogens were detected by real-time polymerase chain reaction and DNA sequencing. Histo-blood group antigens (HBGA) phenotypes of saliva samples and their binding to norovirus protruding proteins were determined by enzyme-linked immunosorbent assay. The HBGA-binding interfaces and the surrounding region were analysed by the MegAlign program of DNAstar 7.1. Twenty-seven individuals in two care units were attacked with AGE at attack rates of 9.02 and 11.68%. Eighteen (78.2%) symptomatic and five (38.4%) asymptomatic individuals were GII.6/b norovirus positive. Saliva-based HBGA phenotyping showed that all symptomatic and asymptomatic cases belonged to A, B, AB or O secretors. Only four (16.7%) out of the 24 tested serum samples showed low blockade activity against HBGA-norovirus binding at the acute phase, whereas 11 (45.8%) samples at the convalescence stage showed seroconversion of such blockade. Specific blockade antibody in the population played an essential role in this norovirus epidemic. A wide HBGA-binding spectrum of GII.6 supports a need for continuous health attention and surveillance in different settings.
Gravitational waves from coalescing neutron stars encode information about nuclear matter at extreme densities, inaccessible by laboratory experiments. The late inspiral is influenced by the presence of tides, which depend on the neutron star equation of state. Neutron star mergers are expected to often produce rapidly rotating remnant neutron stars that emit gravitational waves. These will provide clues to the extremely hot post-merger environment. This signature of nuclear matter in gravitational waves contains most information in the 2–4 kHz frequency band, which is outside of the most sensitive band of current detectors. We present the design concept and science case for a Neutron Star Extreme Matter Observatory (NEMO): a gravitational-wave interferometer optimised to study nuclear physics with merging neutron stars. The concept uses high-circulating laser power, quantum squeezing, and a detector topology specifically designed to achieve the high-frequency sensitivity necessary to probe nuclear matter using gravitational waves. Above 1 kHz, the proposed strain sensitivity is comparable to full third-generation detectors at a fraction of the cost. Such sensitivity changes expected event rates for detection of post-merger remnants from approximately one per few decades with two A+ detectors to a few per year and potentially allow for the first gravitational-wave observations of supernovae, isolated neutron stars, and other exotica.
To improve the endurance performance of long-endurance Unmanned Aerial Vehicles (UAVs), a smart morphing method to adjust the UAV and flight mode continuously during flight is proposed. Using this method as a starting point, a smart morphing long-endurance UAV design is conducted and the resulting improvement in the endurance performance studied. Firstly, the initial overall design of the smart morphing long-endurance UAV is carried out, then the morphing form is designed and various control parameters are selected. Secondly, based on multi-agent theory, an architecture for the smart morphing control system is built and the workflow of the smart morphing control system is planned. The morphing decision method is designed in detail based on the particle swarm optimisation algorithm. Finally, a simulation of the smart morphing approach in the climb and cruise stages is carried out to quantitatively verify the improvement in the endurance performance. The simulation results show that the smart morphing method can improve the cruise time by 4.1% with the same fuel consumption.
The pandemic of coronavirus disease 2019 (COVID-19) has posed serious challenges. It is vitally important to further clarify the epidemiological characteristics of the COVID-19 outbreak for future study and prevention and control measures. Epidemiological characteristics and spatial−temporal analysis were performed based on COVID-19 cases from 21 January 2020 to 1 March 2020 in Shandong Province, and close contacts were traced to construct transmission chains. A total of 758 laboratory-confirmed cases were reported in Shandong. The sex ratio was 1.27: 1 (M: F) and the median age was 42 (interquartile range: 32–55). The high-risk clusters were identified in the central, eastern and southern regions of Shandong from 25 January 2020 to 10 February 2020. We rebuilt 54 transmission chains involving 209 cases, of which 52.2% were family clusters, and three widespread infection chains were elaborated, occurring in Jining, Zaozhuang and Liaocheng, respectively. The geographical and temporal disparity may alert public health agencies to implement specific measures in regions with different risk, and should attach importance on how to avoid household and community transmission.
Porphyromonas gingivalis has been linked to the development and progression of oesophageal squamous cell carcinoma (ESCC), and is considered to be a high-risk factor for ESCC. Currently, the commonly used methods for P. gingivalis detection are culture or DNA extraction-based, which are either time and labour intensive especially for high-throughput applications. We aimed to establish and evaluate a rapid and sensitive direct quantitative polymerase chain reaction (qPCR) protocol for the detection of P. gingivalis without DNA extraction which is suitable for large-scale epidemiological studies. Paired gingival swab samples from 192 subjects undergoing general medical examinations were analysed using two direct and one extraction-based qPCR assays for P. gingivalis. Tris-EDTA buffer-based direct qPCR (TE-direct qPCR), lysis-based direct qPCR (lysis-direct qPCR) and DNA extraction-based qPCR (kit-qPCR) were used, respectively, in 192, 132 and 60 of these samples for quantification of P. gingivalis. The sensitivity and specificity of TE-direct qPCR was 95.24% and 100% compared with lysis-direct qPCR, which was 100% and 97.30% when compared with kit-qPCR; TE-direct qPCR had an almost perfect agreement with lysis-direct qPCR (κ = 0.954) and kit-qPCR (κ = 0.965). Moreover, the assay time used for TE-direct qPCR was 1.5 h. In conclusion, the TE-direct qPCR assay is a simple and efficient method for the quantification of oral P. gingivalis and showed high sensitivity and specificity compared with routine qPCR.
The relative effect of the atypical antipsychotic drugs and conventional agents on neurocognition in patients with early-stage schizophrenia has not been comprehensively determined.
The present study aimed to assess the cognitive effects of atypical and conventional antipsychotic drugs on neurocognition under naturalistic treatment conditions.
In a 12 months open-label, multicenter study, 698 patients with early-stage schizophrenia (< 5 years) were monotherapy with chlorpromazine, sulpiride, clozapine, risperidone, olanzapine, quetiapine or aripiprazole. Wechsler Memory Scale--Revised Visual Reproduction Test, Wechsler Adult Intelligence Scale Revised Digit Symbol Test and Digit-span Task Test, Trail Making Tests Part A and Part B, and Wisconsin Card Sorting Test were administered at baseline and 12 months follow-up evaluation. The primary outcome was change in a cognitive composite score after 12 months of treatment.
Compared with scores at baseline, the composite cognitive test scores and individual test scores had significant improvement for all seven treatment groups at 12-month follow-up evaluation (all p-values ≤ 0.013). However, olanzapine and quetiapine provided greater improvement than that provided by chlorpromazine and sulpiride in the composite score, processing speed and executive function (all p-values ≤ 0.045).
Both conventional and atypical antipsychotic medication long-term maintenance treatment can benefit congitive function in patients with early-stage schizophrenia, but olanzapine and quetiapine may be superior to chlorpromazine and sulpiride in improving some areas of neurocognitive function.
There are strong links between circadian disturbance and some of the most characteristic symptoms of clinical major depressive disorder (MDD). However there are no published studies of changes in expression of clock genes or of other neuropeptides related to circadian-rhythm regulation, which may influence recurrent susceptibility after treatment with antidepressant in MDD.
Blood samples were collected from twelve healthy controls and twelve male major depressive patients pre- and post- treated with escitalopram for eight weeks at 4-hour intervals for 24 hours. Outcome measures were the relative expression of mRNA of clock genes (hPERIOD1, hPERIOD2, hPERIOD3, hCRY1, hBMAL1, hNPAS2 and hGSK-3beta) and the levels of serum melatonin, Vasoactive Intestinal Peptide (VIP), cortisol, Adrenocorticotropic Hormone (ACTH), Insulin-like Growth Factor-1(IGF-1) and growth hormone (GH) in twelve healthy controls and twelve pre- and post- treated MDD patients.
Compared with healthy controls, MDD patients showed disruptions in diurnal rhythms of expression of hPERIOD1, hPERIOD2, hCRY1, hBMAL1, hNPAS2 and hGSK-3beta, along with disruptions in diurnal rhythms of release of melatonin, VIP, cortisol, ACTH, IGF-1, and GH. Several of these disruptions (hPER1, hCRY1, melatonin, VIP, cortisol, ACTH, and IGF-1) persisted after eight weeks escitalopram treatment, as did elevation of 24-hour levels of VIP and decreases in 24-hour levels of cortisol and ACTH.
These persisted neurobiological changes may play a role in MDD symptoms that are thought to contribute to recurrence vulnerability and in maintenance therapy for a long term.
To investigate the difference of visual pattern memory among first-episode treatment-naive patients with deficit and nondeficit schizophrenia.
199 first-episode treatment-naive patients with schizophrenia, and 148 controls were recruited. Schedule for the Deficit Syndrome (SDS) was used to categorize the patients into deficit or nondeficit subtype. Pattern Recognition Memory (PRM) was used to test the immediate and delayed mode of visual pattern memory. Positive and Negative Symptom Scale PANSS was used to assess the degree of patients symptoms.
The PRM immediate mode and delayed mode percent correct was significant lower and time latency was significant longer in two subtypes of patients. There were no significant difference in the performance of immediate mode of PRM between deficit and nondeficit patients[(86.49 ± 15.34) vs. (87.28 ± 16.00), P=0.960]. But the impairment was more severe in patients with deficit schizophrenia [percent correct (63.10 ± 19.17) vs. (70.69 ± 15.34), P< 0.001 time latency 5086.80 ± 7528.54 vs. 3527.40 ± 3649.08 P=0.024] in the delayed mode. and PRM has no significant correlation with the negative symptoms of deficit schizophrenia.
There were significant difference in the performance of immediate and delayed mode of PRM between patients and controls. The difference between first-episode treatment-naïve deficit schizophrenia and nondeficit schizophrenia was only in delayed mode of PRM, and has no correlation with the primary negative symptoms. The deficit schizophrenia is a subtype of schizophrenia with unique impairment of cognitive functions.
Planning ability as a critical component of executive function has been used to investigate prefrontal cortex (PFC) function in Schizophrenia patients by several neuroimaging studies. However, the changes of PFC activation after effective antipsychotic treatment are still unclear.
The aim of this study is to explore whether there is any variation in the prefrontal hemodynamic response during Tower of London test after 6 weeks’ antipsychotic treatment in schizophrenia patients, and the relationship between the changes in PFC activation and some demographic factors as well as the severity of the patients’ psychiatric symptoms.
40 patients with first-episode schizophrenia were recruited for the present study. 28-channel NIRS (near infrared spectroscopy) was used to measure changes in hemoglobin concentration in the prefrontal cortical surface area during Tower of London (TOL) test—a classic neuropsychological test for planning abilities. The patients were examined before treatment and after six weeks’ treatment with second-generation antipsychotic medicines.
After the short-term treatment, the patients’ TOL test performance and the activations in PFC during the task period did not differ from baseline (P>0.05), although the psychiatric symptoms of the patients were improved significantly(positive subscale score 18.25±2.86 & 12.75±2.60; general psychopathology 33.67±3.65 & 27.00±3.67; PANSS total score 72.25±7.07 & 55.42±7.53; P<0.001).
It suggests that the impairment of cognitive function and the function of the PFC of schizophrenia patients would not be improved with the improvement of psychiatric symptoms, as further support the hypothesis that PFC damage is a durable impairment for schizophrenia.
As an epigenetic modification, DNA methylation may reflect the interaction between genetic and environmental factors in the development of schizophrenia (SCZ). Catechol-O-methyltransferase (COMT) gene is a promising candidate gene of SCZ. In the present study, we investigate the association of COMT methylation with the risk of SCZ using bisulfite pyrosequencing technology. Significant association between DNA methylation of COMT and the risk of SCZ is identified (P = 1.618e−007). A breakdown analysis by gender shows that the significance is driven by males (P = 3.310e−009), but not by females. DNA methylation of COMT is not significantly associated with SCZ clinical phenotypes, including p300 and cysteine level. No interaction is found between COMT genotypes and the percent methylation of this gene. Receiver operating characteristic (ROC) curve shows that DNA methylation of COMT is able to predict the SCZ risk in males (area under curve [AUC] = 0.802, P = 1.91e−007). The current study indicates the clinical value of COMT methylation as a potential male-specific biomarker in SCZ diagnosis.
Coronavirus disease 2019 (COVID-19) pandemic is a major public health concern all over the world. Little is known about the impact of COVID-19 pandemic on mental health in the general population. This study aimed to assess the mental health problems and associated factors among a large sample of college students during the COVID-19 outbreak in China.
This cross-sectional and nation-wide survey of college students was conducted in China from 3 to 10 February 2020. A self-administered questionnaire was used to assess psychosocial factors, COVID-19 epidemic related factors and mental health problems. Acute stress, depressive and anxiety symptoms were measured by the Chinese versions of the impact of event scale-6, Patient Health Questionnaire-9 and Generalized Anxiety Disorder-7, respectively. Univariate and hierarchical logistic regression analyses were performed to examine factors associated with mental health problems.
Among 821 218 students who participated in the survey, 746 217 (90.9%) were included for the analysis. In total, 414 604 (55.6%) of the students were female. About 45% of the participants had mental health problems. The prevalence rates of probable acute stress, depressive and anxiety symptoms were 34.9%, 21.1% and 11.0%, respectively. COVID-19 epidemic factors that were associated with increased risk of mental health problems were having relatives or friends being infected (adjusted odds ratio = 1.72–2.33). Students with exposure to media coverage of the COVID-19 ≥3 h/day were 2.13 times more likely than students with media exposure <1 h/day to have acute stress symptoms. Individuals with low perceived social support were 4.84–5.98 times more likely than individuals with high perceived social support to have anxiety and depressive symptoms. In addition, senior year and prior mental health problems were also significantly associated with anxiety or/and depressive symptoms.
In this large-scale survey of college students in China, acute stress, anxiety and depressive symptoms are prevalent during the COVID-19 pandemic. Multiple epidemic and psychosocial factors, such as family members being infected, massive media exposure, low social support, senior year and prior mental health problems were associated with increased risk of mental health problems. Psychosocial support and mental health services should be provided to those students at risk.
Patients with severe mental disorders in low-resource settings have limited access to services, resulting in overwhelming caregiving burden for families. In extreme cases, this has led to the long-term restraining of patients in their homes. China underwent a nationwide initiative to unlock patients and provide continued treatment. This study aims to quantify household economic burden in families after unlocking and treatment, and to identify factors associated with increased burden due to schizophrenia.
A total of 264 subjects were enrolled from three geographically diverse provinces in 2012. Subjects were patients with schizophrenia who were previously put under restraints and had participated in the ‘unlocking and treatment’ intervention. The primary outcome was the current household economic burden, obtained from past year financial information collected through on-site interview. Patient disease characteristics, treatment, outcomes and family caregiving burden were collected as well. Univariate and multivariate linear regression were used to construct risk factor models for indirect economic burden.
After participating in the intervention, 85% of patients continued to receive mental health services, 70% used medication as prescribed and 80% were never relocked. Family members reported significantly decreased caregiving burden after receiving the intervention. Mean direct and indirect household economic burdens were CNY963 (US$31.7) and CNY11 724 (US$1670) per year, respectively, while family total income was on average CNY12 108 (US$1913) per year. Greater disease severity and poorer patient psychosocial function at time of study were found to be independent factors related to increased indirect burden.
The ‘unlocking and treatment’ intervention has improved the lives of patients and families. Indirect burden due to disease is still a major economic issue that needs to be addressed, potentially through improving treatment and patient functioning. Our findings contribute to the unravelling and eventual elimination of chronic restraining of mentally ill patients in low-resource settings.
We study star formation and metallicity enrichment histories of 24 massive galaxies at 1.6 < z < 2.5. Deep slitless spectroscopy + imaging data set collected from multiple HST surveys allows robust determination of their SEDs. Our new SED modeling with no functional assumptions on star formation histories revels that 1. most of the sample galaxies have already formed >50% of their extant masses ∼1.5 Gyr before the time of observed redshifts, with a trend where more massive galaxies form earlier, 2. most of our galaxies already have stellar metallicities compatible with those of local early-type galaxies, and 3. inferred metallicities are on average ∼ 0.25 dex higher than observed gas-phase metallicities of star forming galaxies at the time of their formation. Continuation of low-level star formation, rather than abrupt termination of star forming activity, may explain the observed gap of metallicities.
This study aimed to classify the pre-auricular sinus before performing radical dissection, so as to achieve optimal aesthetic results.
The recent five-year clinical data of 53 patients with a congenital pre-auricular sinus and infection treated in the hospital were reviewed. According to the sinus course, pre-auricular and post-auricular types were defined, and regional dissection was performed using the modified supra-auricular or post-auricular approach.
All patients achieved primary intention healing of the incision, and were followed up for six months to five years. No recurrence was found, and the incision scar was completely concealed.
Surgical approaches for regional dissection might be adopted based on the different types of pre-auricular sinuses, and further radical dissection might be performed to achieve optimal aesthetic results.
Enhancing the supply of arginine (Arg), a semi-essential amino acid, has positive effects on immune function in dairy cattle experiencing metabolic stress during early lactation. Our objective was to determine the effects of Arg supplementation on biomarkers of liver damage and inflammation in cows during early lactation. Six Chinese Holstein lactating cows with similar BW (508 ± 14 kg), body condition score (3.0), parity (4.0 ± 0), milk yield (30.6 ± 1.8 kg) and days in milk (20 ± days) were randomly assigned to three treatments in a replicated 3 × 3 Latin square design balanced for carryover effects. Each period was 21 days with 7 days for infusion and 14 days for washout. Treatments were (1) Control: saline; (2) Arg group: saline + 0.216 mol/day l-Arg; and (3) Alanine (Ala) group: saline + 0.868 mol/day l-Ala (iso-nitrogenous to the Arg group). Blood and milk samples from the experimental cows were collected on the last day of each infusion period and analyzed for indices of liver damage and inflammation, and the count and composition of somatic cells in milk. Compared with the Control, the infusion of Arg led to greater concentrations of total protein, immunoglobulin M and high density lipoprotein cholesterol coupled with lower concentrations of haptoglobin and tumor necrosis factor-α, and activity of aspartate aminotransferase in serum. Infusion of Ala had no effect on those biomarkers compared with the Control. Although milk somatic cell count was not affected, the concentration of granulocytes was lower in response to Arg infusion compared with the Control or Ala group. Overall, the biomarker analyses indicated that the supplementation of Arg via the jugular vein during early lactation alleviated inflammation and metabolic stress.
This study aimed to investigate endoscopic revision septoplasty with semi-penetrating straight and circular incisions in patients for whom septoplasty was unsuccessful.
Patients in this study (n = 14) had a deviation of the nasal septum after septoplasty. Pre-operative and post-operative assessments were performed using a visual analogue scale and nasal endoscope. Semi-penetrating straight and circular incisions in front of the caudal septum and at the margin of the nasal septal cartilage–bone defect, respectively, were made. The mucoperichondrium and mucoperiosteum were bilaterally dissected until interlinkage with the cartilage–bone defect was achieved. Mucous membranes within the circular incision as well as the right mucoperichondrium and mucoperiosteal flaps were protected by pushing them to the right. This exposed the osteocartilaginous framework and allowed correction of the residual deviation. The patients were followed up for 30–71 months.
For nasal obstruction and headaches, a significant improvement was noted in post-operative compared to pre-operative visual analogue scale scores. No patients had septal deviations, saddle nose, false hump nose or contracture of the nasal columella.
The technique allowed exposure of the septal osteocartilaginous framework and a broad operational vision, which enabled successful correction of various deformities of the nasal septum.
To compare the epidemiologic features (e.g. settings and transmission mode) and patient clinical characteristics associated with outbreaks of different norovirus (Nov) strains, we retrospectively analysed data of Nov outbreaks occurring in Guangzhou, China from 2012 to 2018. The results suggested that outbreaks of Nov GII.2, GII.17 and GII.4 Sydney exhibited different outbreak settings, transmission modes and symptoms. GII.2 outbreaks mainly occurred in kindergartens, elementary and high schools and were transmitted mainly through person-to-person contact. By contrast, GII.4 Sydney outbreaks frequently occurred in colleges and were primarily associated with foodborne transmission. Cases from GII.2 and GII.17 outbreaks reported vomiting more frequently than those from outbreaks associated with GII.4 Sydney.
Optimizing the dietary calcium (Ca) level is essential to maximize the eggshell quality, egg production and bone formation in poultry. This study aimed to establish the Ca requirements of egg-type duck breeders from 23 to 57 weeks of age on egg production, eggshell, incubation, tibial, plasma and ovary-related indices, as well as the expression of matrix protein-related genes. Totally, 450 Longyan duck breeders aged 21 weeks of age were allotted randomly into five treatments, each with six replicates of 15 individually caged birds. The data collection started from 23 weeks of age and continued over the following 35 weeks. The five groups corresponded to five dietary treatments containing either 2.8%, 3.2%, 3.6%, 4.0% or 4.4% Ca. The tested dietary Ca levels increased (linear, P <0.01) egg production and egg mass, and linearly improved (P <0.01) the feed conversion ratio (FCR). Increasing the dietary Ca levels from 2.8% to 4.4% increased (P <0.01) the eggshell thickness and eggshell content. The tested Ca levels showed a quadratic effect on eggshell thickness and ovarian weight (P <0.01); the highest values were obtained with the Ca levels 4.0% and 3.6%, respectively. Dietary Ca levels affected the small yellow follicles (SYF) number and SYF weight/ovarian weight, and the linear response (P <0.01) was significant vis-à-vis SYF number. In addition, dietary Ca levels increased (P <0.05) the tibial dry weight, breaking strength, mineral density and ash content. Plasma and tibial phosphorus concentration exhibited a quadratic (P <0.01) response to dietary Ca levels. Plasma calcitonin concentration linearly (P <0.01) increased as dietary Ca levels increased. The relative expression of carbonic anhydrase 2 in the uterus rose (P <0.01) with the increment of dietary Ca levels, and the highest value was obtained with 3.2% Ca. In conclusion, Longyan duck breeders fed a diet with 4.0% Ca had superior eggshell and tibial quality, while those fed a diet with 3.6% Ca had the heaviest ovarian weights. The regression model indicated that the dietary Ca levels 3.86%, 3.48% and 4.00% are optimal levels to obtain maximum eggshell thickness, ovarian weight and tibial mineral density, respectively.
The seasonality of individual influenza subtypes/lineages and the association of influenza epidemics with meteorological factors in the tropics/subtropics have not been well understood. The impact of the 2009 H1N1 pandemic on the prevalence of seasonal influenza virus remains to be explored. Using wavelet analysis, the periodicities of A/H3N2, seasonal A/H1N1, A/H1N1pdm09, Victoria and Yamagata were identified, respectively, in Panzhihua during 2006–2015. As a subtropical city in southwestern China, Panzhihua is the first industrial city in the upper reaches of the Yangtze River. The relationship between influenza epidemics and local climatic variables was examined based on regression models. The temporal distribution of influenza subtypes/lineages during the pre-pandemic (2006–2009), pandemic (2009) and post-pandemic (2010–2015) years was described and compared. A total of 6892 respiratory specimens were collected and 737 influenza viruses were isolated. A/H3N2 showed an annual cycle with a peak in summer–autumn, while A/H1N1pdm09, Victoria and Yamagata exhibited an annual cycle with a peak in winter–spring. Regression analyses demonstrated that relative humidity was positively associated with A/H3N2 activity while negatively associated with Victoria activity. Higher prevalence of A/H1N1pdm09 and Yamagata was driven by lower absolute humidity. The role of weather conditions in regulating influenza epidemics could be complicated since the diverse viral transmission modes and mechanism. Differences in seasonality and different associations with meteorological factors by influenza subtypes/lineages should be considered in epidemiological studies in the tropics/subtropics. The development of subtype- and lineage-specific prevention and control measures is of significant importance.