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The takeoff-mass of a two-stage-to-orbit Rocket-Based Combined Cycle Engine-Rocket (RBCC-RKT) launch vehicle is a crucial factor in its comprehensive performance. This paper optimizes the takeoff-mass together with the trajectory by reformulating it to a nonlinear optimal control problem. The range of the second stage rocket mass is considered as a process constraint. When the scopes of initial and terminal states are specified, the problem can be solved by using the Gauss pseudo-spectral method (GPM). In order to reduce the convergent difficulty caused by using table data, the data in different stages are utilized by employing an integrated interpolation strategy through the optimization. Simulation results show that the mass can be effectively optimized to meet the inertia mass ratio constraint of the first-stage, and the separation of Mach number and altitude can be optimized at the same time.
Copy number variations (CNVs), as an important source of genetic variation, can affect a wide range of phenotypes by diverse mechanisms. The somatostatin receptor 2 (SSTR2) gene plays important roles in cell proliferation and apoptosis. Recently, this gene was mapped to a CNV region, which encompasses quantitative trait loci of cattle economic traits including body weight, marbling score, etc. Therefore, SSTR2 CNV may exhibit phenotypic effects on cattle growth traits. In the current study, distribution of SSTR2 gene CNVs was investigated in six Chinese cattle breeds (XN, QC, NY, JA, LX and PN), and the results showed higher CNV polymorphisms in XN, QC and NY cattle. Next, association analysis between growth traits and SSTR2 CNV was performed for XN, QC and NY cattle. In NY, individuals with fewer copies showed better performance than those with more copies. Further, the effects of SSTR2 CNV on the SSTR2 mRNA level were also investigated, but revealed no significant correlation in either muscle or adipose tissue of adult NY cattle. The results suggested the potential for use of SSTR2 CNV as a marker for the molecular breeding of NY cattle.
Rabies is one of the major public health problems in China, and the mortality rate of rabies remains the highest among all notifiable infectious diseases. A meta-analysis was conducted to investigate the post-exposure prophylaxis (PEP) vaccination rate and risk factors for human rabies in mainland China. The PubMed, Web of Science, Chinese National Knowledge Infrastructure, Chinese Science and Technology Periodical and Wanfang databases were searched for articles on rabies vaccination status (published between 2007 and 2017). In total, 10 174 human rabies cases from 136 studies were included in this meta-analysis. Approximately 97.2% (95% confidence interval (CI) 95.1–98.7%) of rabies cases occurred in rural areas and 72.6% (95% CI 70.0–75.1%) occurred in farmers. Overall, the vaccination rate in the reported human rabies cases was 15.4% (95% CI 13.7–17.4%). However, among vaccinated individuals, 85.5% (95% CI 79.8%–83.4%) did not complete the vaccination regimen. In a subgroup analysis, the PEP vaccination rate in the eastern region (18.8%, 95% CI 15.9–22.1%) was higher than that in the western region (13.3%, 95% CI 11.1–15.8%) and this rate decreased after 2007. Approximately 68.9% (95% CI 63.6–73.8%) of rabies cases experienced category-III exposures, but their PEP vaccination rate was 27.0% (95% CI 14.4–44.9%) and only 6.1% (95% CI 4.4–8.4%) received rabies immunoglobulin. Together, these results suggested that the PEP vaccination rate among human rabies cases was low in mainland China. Therefore, standardised treatment and vaccination programs of dog bites need to be further strengthened, particularly in rural areas.
The response of soil microbial communities to soil quality changes is a sensitive indicator of soil ecosystem health. The current work investigated soil microbial communities under different fertilization treatments in a 31-year experiment using the phospholipid fatty acid (PLFA) profile method. The experiment consisted of five fertilization treatments: without fertilizer input (CK), chemical fertilizer alone (MF), rice (Oryza sativa L.) straw residue and chemical fertilizer (RF), low manure rate and chemical fertilizer (LOM), and high manure rate and chemical fertilizer (HOM). Soil samples were collected from the plough layer and results indicated that the content of PLFAs were increased in all fertilization treatments compared with the control. The iC15:0 fatty acids increased significantly in MF treatment but decreased in RF, LOM and HOM, while aC15:0 fatty acids increased in these three treatments. Principal component (PC) analysis was conducted to determine factors defining soil microbial community structure using the 21 PLFAs detected in all treatments: the first and second PCs explained 89.8% of the total variance. All unsaturated and cyclopropyl PLFAs except C12:0 and C15:0 were highly weighted on the first PC. The first and second PC also explained 87.1% of the total variance among all fertilization treatments. There was no difference in the first and second PC between RF and HOM treatments. The results indicated that long-term combined application of straw residue or organic manure with chemical fertilizer practices improved soil microbial community structure more than the mineral fertilizer treatment in double-cropped paddy fields in Southern China.
Recent studies indicate that early postnatal period is a critical window for gut microbiota manipulation to optimise the immunity and body growth. This study investigated the effects of maternal faecal microbiota orally administered to neonatal piglets after birth on growth performance, selected microbial populations, intestinal permeability and the development of intestinal mucosal immune system. In total, 12 litters of crossbred newborn piglets were selected in this study. Litter size was standardised to 10 piglets. On day 1, 10 piglets in each litter were randomly allotted to the faecal microbiota transplantation (FMT) and control groups. Piglets in the FMT group were orally administrated with 2ml faecal suspension of their nursing sow per day from the age of 1 to 3 days; piglets in the control group were treated with the same dose of a placebo (0.1M potassium phosphate buffer containing 10% glycerol (vol/vol)) inoculant. The experiment lasted 21 days. On days 7, 14 and 21, plasma and faecal samples were collected for the analysis of growth-related hormones and cytokines in plasma and lipocalin-2, secretory immunoglobulin A (sIgA), selected microbiota and short-chain fatty acids (SCFAs) in faeces. Faecal microbiota transplantation increased the average daily gain of piglets during week 3 and the whole experiment period. Compared with the control group, the FMT group had increased concentrations of plasma growth hormone and IGF-1 on days 14 and 21. Faecal microbiota transplantation also reduced the incidence of diarrhoea during weeks 1 and 3 and plasma concentrations of zonulin, endotoxin and diamine oxidase activities in piglets on days 7 and 14. The populations of Lactobacillus spp. and Faecalibacterium prausnitzii and the concentrations of faecal and plasma acetate, butyrate and total SCFAs in FMT group were higher than those in the control group on day 21. Moreover, the FMT piglets have higher concentrations of plasma transforming growth factor-β and immunoglobulin G, and faecal sIgA than the control piglets on day 21. These findings indicate that early intervention with maternal faecal microbiota improves growth performance, decreases intestinal permeability, stimulates sIgA secretion, and modulates gut microbiota composition and metabolism in suckling piglets.
Studies from high-income countries report moderate-to-strong positive associations between alcohol use disorder (AUD) and other mental disorders, but there is little evidence about the comorbidity of AUD from low-and-middle-income countries.
A sample of 74 752 adults from five provinces that account for >12% of China's adult population was screened using the General Health Questionnaire, and the Structured Clinical Interview for DSM-IV was administered by psychiatrists to a subsample of 9619 males. The associations between AUD and other mental disorders at each site and the characteristics of men with AUD with and without comorbid mental disorders were estimated using logistic regression and summarized across sites using meta-analysis. Generalized estimation equations estimated the associations between the clinical features of alcohol dependence and comorbidity.
Robust inverse associations were found between current AUD and any mood disorder (adjusted OR = 0.6, 95% CI = 0.4–0.8) and any anxiety disorder (OR = 0.5, 95% CI = 0.3–1.0). Compared with men without AUD, men with AUD without comorbid disorders were more likely to be middle-aged, to be currently married, and to have higher family incomes. Men with comorbid AUD and other disorders were more likely to have the clinical features of alcohol dependence than men with AUD without comorbid disorders.
Inverse associations between AUD and other mental disorders and the higher social status of men with AUD than men without AUD found in this large, representative sample of community-dwelling Chinese males highlight the importance of considering the local substance-use culture when designing clinical or preventive interventions for addictive conditions.
Bacillary dysentery continues to be a major health issue in developing countries and ambient temperature is a possible environmental determinant. However, evidence about the risk of bacillary dysentery attributable to ambient temperature under climate change scenarios is scarce. We examined the attributable fraction (AF) of temperature-related bacillary dysentery in urban and rural Hefei, China during 2006–2012 and projected its shifting pattern under climate change scenarios using a distributed lag non-linear model. The risk of bacillary dysentery increased with the temperature rise above a threshold (18·4 °C), and the temperature effects appeared to be acute. The proportion of bacillary dysentery attributable to hot temperatures was 18·74% (95 empirical confidence interval (eCI): 8·36–27·44%). Apparent difference of AF was observed between urban and rural areas, with AF varying from 26·87% (95% eCI 16·21–36·68%) in urban area to −1·90% (95 eCI −25·03 to 16·05%) in rural area. Under the climate change scenarios alone (1–4 °C rise), the AF from extreme hot temperatures (>31·2 °C) would rise greatly accompanied by the relatively stable AF from moderate hot temperatures (18·4–31·2 °C). If climate change proceeds, urban area may be more likely to suffer from rapidly increasing burden of disease from extreme hot temperatures in the absence of effective mitigation and adaptation strategies.
With the aid of the Green's function method and complex function method, the scattering problem of SH-wave by a cylindrical inclusion and a semi-cylindrical hollow in the bi-material half space is considered to obtain the steady state response. Firstly, by the means of the image method, the essential solution of displacement field as well as Green's function is constructed which satisfies the stress free on the horizontal boundary in a right-angle space including a cylindrical inclusion and a semi-cylindrical hollow and bearing a harmonic out-plane line source force at any point on the vertical boundary. Secondly, the bi-material half space is divided into two parts along the vertical interface, and the first kind of Fredholm integral equations containing undetermined anti-plane forces at the linking section is established by “the conjunction method” and “the crack-division method”, the integral equations are reduced to the algebraic equations consisting of finite items by effective truncation. Finally, dynamic stress concentration factor around the edge of cylindrical inclusion and dynamic stress intensity factor at crack tip are calculated, and the influences of effect of interface and different combination of material parameters, etc. on dynamic stress concentration factor and dynamic stress intensity factor are discussed.
Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a serious hospital and community-acquired infection and some strains are associated with greater severity. We investigated the clinical variability and molecular characteristics of MRSA infections in Shenzhen, China through a study at nine sentinel hospitals from January to December 2014. MRSA infections were classified as community-associated (CA-MRSA), healthcare-associated (HA-MRSA), and healthcare-associated community-onset (HACO-MRSA). In total, 812 MRSA isolates were collected and 183 of these were selected for further study. Patients with HA-MRSA infections were generally of greater age compared to other groups. Distinct body site and clinical presentations were evident in infected patients, e.g. CA-MRSA (skin and soft tissue, 53%), HA-MRSA (respiratory tract, 22%; surgical site, 20%; trauma wounds, 20%) and HACO-MRSA (mastitis, 47%). In contrast to HA-MRSA, other categories of strains were significantly more susceptible to gentamicin, sulfamethoxazole/trimethoprim, and tetracycline. No resistance to vancomycin or linezolid was recorded. The predominant clonal lineage within each strain category was CC59-t437-SCCmec IV/V-agr I (CA, 51·4%; HA, 28·9%; HACO, 52·9%) which exhibited characteristics of a traditional CA clone together with agr I which is more often associated with HA clones. In conclusion, for the three categories of MRSA infections, there were significant differences in clinical characteristics of patients, but the predominant clone in each category shared a similar genetic background which suggests that transmission of MRSA strains has occurred between the community and hospitals in Shenzhen.
The genetic influences in human brain structure and function and impaired functional connectivities are the hallmarks of the schizophrenic brain. To explore how common genetic variants affect the connectivities in schizophrenia, we applied genome-wide association studies assaying the abnormal neural connectivities in schizophrenia as quantitative traits.
We recruited 161 first-onset and treatment-naive patients with schizophrenia and 150 healthy controls. All the participants underwent scanning with a 3 T-magnetic resonance imaging scanner to acquire structural and functional imaging data and genotyping using the HumanOmniZhongHua-8 BeadChip. The brain-wide association study approach was employed to account for the inherent modular nature of brain connectivities.
We found differences in four abnormal functional connectivities [left rectus to left thalamus (REC.L–THA.L), left rectus to right thalamus (REC.L–THA.R), left superior orbital cortex to left thalamus (ORBsup.L–THA.L) and left superior orbital cortex to right thalamus (ORBsup.L–THA.R)] between the two groups. Univariate single nucleotide polymorphism (SNP)-based association revealed that the SNP rs6800381, located nearest to the CHRM3 (cholinergic receptor, muscarinic 3) gene, reached genomic significance (p = 1.768 × 10−8) using REC.L–THA.R as the phenotype. Multivariate gene-based association revealed that the FAM12A (family with sequence similarity 12, member A) gene nearly reached genomic significance (nominal p = 2.22 × 10–6, corrected p = 0.05).
Overall, we identified the first evidence that the CHRM3 gene plays a role in abnormal thalamo-orbital frontal cortex functional connectivity in first-episode treatment-naive patients with schizophrenia. Identification of these genetic variants using neuroimaging genetics provides insights into the causes of variability in human brain development, and may help us determine the mechanisms of dysfunction in schizophrenia.
Arginine kinase (AK) is an important regulation factor of energy metabolism in invertebrate. An arginine kinase gene, named HaAK, was identified to be differentially expressed between Cry1Ac-susceptible (96S) and Cry1Ac-resistant (Bt-R) Helicoverpa armigera larvae using cDNA-amplification fragment length polymorphism analysis. The full-length open reading frame sequence of HaAK gene with 1068 bp was isolated from H. armigera. Quantitative reverse transcription polymerase chain reaction assay revealed that HaAK gene is specifically expressed in multiple tissues and at larval developmental stages. The peak expression level of HaAK was detected in the midgut of the fifth-instar larvae. Moreover, the expression of HaAK was obviously down-regulated in Bt-R larvae. We further constructed a dsRNA vector directly targeting HaAK and employed RNAi technology to control the larvae. The feeding bioassays showed that minute quantities of dsRNA could greatly increase the larval mortality and delay the larval pupation. Silencing of HaAK significantly retarded the larval development, indicating that HaAK is a potential target for RNA interference-based pest management.
This paper presents a method for noise-free recording of the keyboard-based musical instruments. By integrating an r-shaped triboelectric generator (TEG) into the keyboard of a piano, it can produce electric signal while playing music due to the combination of contact electrification and electric induction. We investigated the electric signal and developed a graphical user interface to convert the electric signal back to music. Using the piano and the graphical user interface, active noise-free recording can be realized. Namely, only the sound produced by the piano can be converted and recorded, while other noise in the environment can be filtered automatically.
This paper describes the system architecture of a newly constructed radio telescope – the Boolardy engineering test array, which is a prototype of the Australian square kilometre array pathfinder telescope. Phased array feed technology is used to form multiple simultaneous beams per antenna, providing astronomers with unprecedented survey speed. The test array described here is a six-antenna interferometer, fitted with prototype signal processing hardware capable of forming at least nine dual-polarisation beams simultaneously, allowing several square degrees to be imaged in a single pointed observation. The main purpose of the test array is to develop beamforming and wide-field calibration methods for use with the full telescope, but it will also be capable of limited early science demonstrations.
The BiFeO3 (BFO) / PbTiO3 (PT) multiferroic ceramic composites with multilayered structure were prepared from orderly laminated BFO and PT tapes by tape casting method. The dielectric constant εr, loss tanδ, remnant polarization Pr and field-induced strain of BFO/PT ceramic composites were 140 (1 kHz), 5% (1 kHz), 12 µC/cm2 (at 80 kV/cm) and 0.06% (at 80 kV/cm) respectively, which were comparable to those pure BFO ceramics and BFO-based solid solutions
A photoactivated ZnO nanomesh with precisely controlled dimensions and geometries is fabricated by using nanosphere lithography process. The nanomesh structures effectively increase the surface-to-volume ratio to improve the sensing response under the same testing gas. And the periodical nanostructures also increase the effective light path and lead to more efficient light activation for gas sensing. With the increase of the photoinduced oxygen ions by UV illumination, a distinguished sensing response is observed at room temperature. In the optimized case, the sensing response (△R/R0) of the ZnO nanomesh at the butanol concentration of 500 ppm is 97.5%, which is 4.54 times higher than the unpatterned one.
A radio-frequency magnetron sputtering technique and subsequent rapid thermal annealing (RTA) at 600, 700, 800, and 900 °C were implemented to grow high-quality Ga-doped MgxZn1-xO (GMZO) epi-layers. The GMZO films were deposited using a radio-frequency magnetron sputtering system and a 4 inch ZnO/MgO/Ga2O3 (75/20/5 wt %) target. The Hall results, X-ray diffraction (XRD), and transmittance were determined and are reported in this paper. The Hall results indicated that the increase in mobility was likely caused by the improved crystallization in the GMZO films after thermal annealing. The XRD results revealed that MgxZn1-xO (111) and MgO2 (200) peaks were obtained in the GMZO films. The absorption edges of the as-grown and annealed GMZO films shifted toward the short wavelength of 373 nm at a transmittance of 90%. According to these results, GMZO films are feasible for forming transparent contact layers for near-ultraviolet light-emitting diodes.
Assessing carbon footprint (CF) of crop production in a whole crop life-cycle could provide insights into the contribution of crop production to climate change and help to identify possible greenhouse gas (GHG) mitigation options. In the current study, data for the major crops of China were collected from the national statistical archive on cultivation area, yield, application rates of fertilizer, pesticide, diesel, plastic film, irrigated water, etc. The CF of direct and indirect carbon emissions associated with or caused by these agricultural inputs was quantified with published emission factors. In general, paddy rice, wheat, maize and soybean of China had mean CFs of 2472, 794, 781 and 222 kg carbon equivalent (CE)/ha, and 0·37, 0·14, 0·12 and 0·10 kg CE/kg product, respectively. For dry crops (i.e. those grown without flooding the fields: wheat, maize and soybean), 0·78 of the total CFs was contributed by nitrogen (N) fertilizer use, including both direct soil nitrous oxide (N2O) emission and indirect emissions from N fertilizer manufacture. Meanwhile, direct methane (CH4) emissions contributed 0·69 on average to the total CFs of flooded paddy rice. Moreover, the difference in N fertilizer application rates explained 0·86–0·93 of the provincial variations of dry crop CFs while that in CH4 emissions could explain 0·85 of the provincial variation of paddy rice CFs. When a 30% reduction in N fertilization was considered, a potential reduction in GHGs of 60 megatonne (Mt) carbon dioxide equivalent from production of these crops was projected. The current work highlights opportunities to gain GHG emission reduction in production of crops associated with good management practices in China.
This study analysed the spatio-temporal distribution and propagation of hand-foot-and-mouth disease (HFMD) in Shenzhen from 2008 to 2010. Specifically, we examined the epidemiological data, temporal distribution and spatial distribution, and then the relationship between meteorological, social factors and the number of reported HFMD cases was analysed using Spearman's rank correlation. Finally, a geographically weighted regression model was constructed for the number of reported HFMD cases in 2009. It was found that three independent variables, i.e. the number of reported HFMD cases in 2008 and, annual average temperature and precipitation, had different spatial impacts on the number of reported HFMD cases in 2009. In addition, these variables accounted for the propagation mechanism of HFMD in the centre and east of Shenzhen, where the high incidence rate areas are located. These results will be of great help in understanding the spatio-temporal distribution of HFMD and developing approaches to prevent this disease.
To investigate different strategies for displaying the hypopharynx and oesophageal entrance during laryngoscopy for hypopharyngeal cancer.
Patients and methods:
A total of 113 patients with hypopharyngeal cancer underwent laryngoscopy prior to surgery. The hypopharynx was displayed by: (1) pulling the anterior cervical skin; (2) having the patient perform the Valsalva balloon-blowing manoeuvre; and (3) injecting oxygen through the biopsy channel to expose the oesophageal entrance. The effect of these methods on visualisation of primary tumour size and extent was assessed.
During pronunciation of the letter ‘e', the hypopharynx was displayed in only 33 patients (29.2 per cent); with anterior cervical skin traction plus the balloon-blowing manoeuvre, the hypopharynx was displayed in 106 patients (93.8 per cent; p < 0.001). The combined strategy was superior especially when judging the extent of posterior pharyngeal wall and postcricoid invasion. Oesophageal entrance involvement was visible in 33 patients upon injecting oxygen through the laryngoscopic biopsy channel, and in 25 patients during radiological examination; laryngoscopy was superior to radiological examination in determining the extent of oesophageal entrance invasion (p = 0.003).
Adequate laryngoscopic display of the hypopharynx could increase the accuracy of pre-treatment hypopharyngeal cancer staging.
Case report data and a matched case-control study were used to investigate the epidemiological characteristics of hand, foot and mouth disease (HFMD) in children in Shenzhen, China between 2008 and 2011. Multivariate analyses were used to evaluate factors associated with severity of infection. Laboratory tests were performed to determine aetiological identification for samples from 163 severe and fatal cases as well as an outpatient-based HFMD sentinel surveillance system (n = 446). All identified EV71 belonged to sub-genotype C4a. No major changes in the CA16 and EV71 viruses were found until the end of 2011. Annual attack rates and the case-severity ratios (CSRs) rose from 0·82/1000 and 0·56/1000, respectively, in 2008 to 2·12/1000 and 6·13/1000 in 2011. The CSR was higher in migrants than in local residents. The adjusted odds ratio (OR) of having a severe attack for being a migrant was 2·45, having a fever >39°C (OR 5·77), visiting a private clinic (OR 2·65), longer time from symptom onset to diagnosis (OR 1·49), visiting a doctor (OR 1·51), early use of intramuscular pyrazolone (OR 3·36), early use of intravenous glucocorticoids (OR 2·28), or the combination of both (OR 3·75). The mortality and increasing case severity appears to be associated with socioeconomic factors including migration and is of worldwide concern.