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.
Alligatorweed [Alternanthera philoxeroides (Mart.) Griseb.] is an invasive semiaquatic weed that poses a serious threat to agricultural production and ecological balance worldwide. However, information about genetic factors associated with the adaptation and invasion mechanisms of this species is limited. Screening for appropriate reference genes is important for gene expression and functional analysis research in A. philoxeroides. In this study, 30 candidate genes that showed stable expression in different A. philoxeroides tissues under various treatments in RNA-seq data were chosen to design quantitative real-time PCR (qRT-PCR) primers. After the amplification specificity validation, 25 candidates were selected and further evaluated in a diverse set of A. philoxeroides samples, including leaf, stem, and root tissues under drought, salinity, heat, chilling, five herbicides, and corresponding untreated controls using qRT-PCR. The delta-CT method, geNorm, NormFinder, BestKeeper, and RefFinder algorithms were used to identify stable reference genes from A. philoxeroides samples. Overall, CoA, RFI2, Tubby, SRP19, and V-ATPase were the top five ideal reference genes in all organs and conditions. Tubby and CoA were the most stable reference genes in the leaf/stem; and RFI2, ERprr, and SPR19 were suitable reference genes for the roots. This work provided a foundation for exploring gene expression profiling of A. philoxeroides, especially those adaptation- and invasion-related genes, which may help in management of this invasive weed.
High fibre intake is associated with reduced mortality risk in both general and chronic kidney disease populations. However, in dialysis patients, such data are limited. Therefore, the association between dietary fibre intake (DFI) and the risk of all-cause and CVD mortality was examined in this study. A total of 1044 maintenance haemodialysis (MHD) patients from eight outpatient dialysis centres in China were included in this study. Data on DFI were collected using 24-h dietary recalls for 3 d in a week and were normalised to actual dry weight. The study outcomes included all-cause and CVD mortality. Over a median of 46 months of follow-up, 354 deaths were recorded, of which 210 (59 %) were due to CVD. On assessing DFI as tertiles, the CVD mortality risk was significantly lower in patients in tertiles 2–3 (≥0·13 g/kg per d; hazard ratio (HR) 0·71; 95 % CI 0·51, 0·97) compared with those in tertile 1 (<0·13 g/kg per d). A similar but non-significant trend was found for the association between DFI (tertiles 2–3 v. tertile 1; HR 0·83; 95 % CI 0·64, 1·07) and all-cause mortality. In summary, higher DFI was associated with lower CVD mortality risk among Chinese MHD patients. This study emphasises the significance of DFI in MHD patients and provides information that is critical for the improvement of dietary guidelines for dialysis patients.
With the progress in science and technology, hazardous chemicals are becoming more essential in chemical products, industrial and agricultural production, and daily life. Hazardous chemicals have poisoning, corrosive, explosive, and combusting natures; once on fire, they can trigger a chain of catastrophic incidences, resulting in casualties, property loss, and environmental pollution and posing hazards to life and property. Using the “8–12” explosion of the Ruihai Logistics warehouse in Tianjin Port (Binhai New District, China), the present study analyzes the characteristics of trauma of the casualties in this accident and the emergency medical rescue strategies. The goals were to improve the ability of emergency rescue in such accidents and to save people’s lives and property to the maximum extent.
Since December 2019, several new infectious diseases, mainly lung diseases caused by novel coronavirus infections, have been discovered in Wuhan, Hubei Province. With the spread of the epidemic, cases in other regions of China and abroad have been confirmed. This sudden outbreak of a new type of infectious disease has seriously threatened people’s health and safety, and China has adopted strong prevention and control measures in response. To provide a reference for international health emergency management workers, this article summarizes, from an academic perspective, the main prevention and control measures taken in China.
Disasters such as an earthquake, a flood, and an epidemic usually lead to large numbers of casualties accompanied by disruption of the functioning of local medical institutions. A rapid response of medical assistance and support is required. Mobile hospitals have been deployed by national and international organizations at disaster situations in the past decades, which play an important role in saving casualties and alleviating the shortage of medical resources. In this paper, we briefly introduce the types and characteristics of mobile hospitals used by medical teams in disaster rescue, including the aspects of structural form, organizational form, and mobile transportation. We also review the practices of mobile hospitals in disaster response and summarize the problems and needs of mobile hospitals in disaster rescue. Finally, we propose the development direction of mobile hospitals, especially on the development of intelligence, rapid deployment capabilities, and modularization, which provide suggestions for further research and development of mobile hospitals in the future.
The aim of this study was to analyze the profile of chest injuries, oxygen therapy for respiratory failure, and the outcomes of victims after the Jiangsu tornado, which occurred on June 23, 2016 in Yancheng City, Jiangsu Province, China.
The clinical records of 144 patients referred to Yancheng City No.1 People’s Hospital from June 23 through June 25 were retrospectively investigated. Of those patients, 68 (47.2%) sustained major chest injuries. The demographic details, trauma history, details of injuries and Abbreviated Injury Scores (AIS), therapy for respiratory failure, surgical procedures, length of intensive care unit (ICU) and hospital stay, and mortality were analyzed.
Of the 68 patients, 41 (60.3%) were female and 27 (39.7%) were male. The average age of the injured patients was 57.1 years. Forty-six patients (67.6%) suffered from polytrauma. The mean thoracic AIS of the victims was calculated as 2.85 (SD = 0.76). Rib fracture was the most common chest injury, noted in 56 patients (82.4%). Pulmonary contusion was the next most frequent injury, occurring in 12 patients (17.7%). Ten patients with severe chest trauma were admitted to ICU. The median ICU stay was 11.7 (SD = 8.5) days. Five patients required intubation and ventilation, one patient was treated with noninvasive positive pressure ventilation (NPPV), and four patients were treated with high-flow nasal cannula (HFNC). Three patients died during hospitalization. The hospital mortality was 4.41%.
Chest trauma was a common type of injury after tornado. The most frequent thoracic injuries were rib fractures and pulmonary contusion. Severe chest trauma is usually associated with a high incidence of respiratory support requirements and a long length of stay in the ICU. Early initiation of appropriate oxygen therapy was vital to restoring normal respiratory function and saving lives. Going forward, HFNC might be an effective and well-tolerated therapeutic addition to the management of acute respiratory failure in chest trauma.
Attention-deficit/hyperactivity disorder (ADHD) is associated with a higher risk of burn injury than in the normal population. Nevertheless, the influence of methylphenidate (MPH) on the risk of burn injury remains unclear. This retrospective cohort study analysed the effect of MPH on the risk of burn injury in children with ADHD.
Data were from Taiwan's National Health Insurance Research Database (NHIRD). The sample comprised individuals younger than 18 years with a diagnosis of ADHD (n = 90 634) in Taiwan's NHIRD between January 1996 and December 2013. We examined the cumulative effect of MPH on burn injury risk using Cox proportional hazards models. We conducted a sensitivity analysis for immortal time bias using a time-dependent Cox model and within-patient comparisons using the self-controlled case series model.
Children with ADHD taking MPH had a reduced risk of burn injury, with a cumulative duration of treatment dose-related effect, compared with those not taking MPH. Compared with children with ADHD not taking MPH, the adjusted hazard ratio for burn injury was 0.70 in children taking MPH for <90 days (95% confidence interval (CI) 0.64–0.77) and 0.43 in children taking MPH for ≥90 days (95% CI 0.40–0.47), with a 50.8% preventable fraction. The negative association of MPH was replicated in age-stratified analysis using time-dependent Cox regression and self-controlled case series models.
This study showed that MPH treatment was associated with a lower risk of burn injury in a cumulative duration of treatment dose-related effect manner.
Maintenance haemodialysis (MHD) is the use of a machine to filter wastes, salts and fluid from blood for at least 3 months to prolong the life of patients with advanced kidney failure. Although low dietary energy intake (DEI) has been observed in MHD patients, few studies have related DEI to the risk of mortality. To explore this relationship, a study included 1039 MHD patients from eight centres was conducted. DEI was assessed by three 24-h diet recalls and was normalised to ideal body weight (IBW). All-cause mortality and CVD mortality were the primary and secondary outcomes, respectively. During a median follow-up of 28 months, a U-shaped relationship was observed between DEI and all-cause or CVD mortality. The risk of all-cause mortality decreased significantly with the increase of DEI in participants with DEI <167·4 kJ/kg IBW per d (hazard ratio (HR) 0·98; 95 % CI 0·96, 1·00) and increased significantly with the increase of DEI in those with DEI ≥167·4 kJ/kg IBW per d (HR 1·12; 95 % CI 1·04, 1·20). Similarly, the risk of CVD mortality decreased with the increase of DEI in participants with DEI <152·7 kJ/kg IBW per d (HR 0·96; 95 % CI 0·93, 0·99) and increased with the increase of DEI in participants with DEI ≥152·7 kJ/kg IBW per d (HR 1·11; 95 % CI 1·04, 1·18). In summary, there was a U-shaped association between DEI and all-cause or CVD mortality, with a turning point at about 167·4 and 152·7 kJ/kg IBW per d, respectively, in MHD patients.
The aim of this study is to characterize the injury profiles and outcomes of victims of a tornado in Jiangsu Province, China.
This study retrospectively investigated the clinical records of 144 patients treated at a teaching hospital due to a tornado. Each patient’s demographic data, diagnosis, injury types, causes of injury, infection status, and outcomes were all reviewed.
Of the 144 patients, 64 (44.4%) were male, and 80 (55.6%) were female. The patients’ ages ranged from 2 months to 94 years; 91 (63.19%) were admitted within the first 12 h after the disaster. The most frequently injured sites were the body surfaces (24.48%), followed by the limbs and pelvis (21.79%) and chest (20.3%). Soft-tissue injuries and fractures were the most frequent injuries. Traumatic brain injuries were the main causes of death. Tornado-related injuries were primarily caused by flying/falling bricks, wood, and glass. Twenty-three (15.9%) patients suffered from infections, which consisted mainly of skin/soft tissue infections and pneumonia.
Destructive tornadoes often cause heavy casualties with little warning. Medical aid agencies must be prepared to accommodate the massive numbers of injured patients after a catastrophe. Proper triage and prompt treatment of injured victims may decrease mortality. (Disaster Med Public Health Preparedness. 2019;xx:xxx-xxx).
This paper investigates a wideband and low axial ratio circularly polarized (CP) antenna, which is composed of a monopole on a novel polarization rotating reflective surface (PRRS) based on a corner-truncated artificial magnetic conductor (AMC) structure. By adjusting the dimensions of truncated corner properly, the PRRS has two polarization rotation (PR) frequency points. Then, a large PR band of 18% (5.55–6.65 GHz) can be achieved with two adjacent PR frequency points coming together. The profile of the newly PRRS is only0.04λ0. With corner-truncated AMC-based PRRS loading, a measured impedance bandwidth of 1.8 GHz (5.4–7.2 GHz) and the 3 dB axial ratio bandwidth of 1 GHz (5.55–6.65 GHz) could be obtained by the monopole antenna and validated by measurements. The values of AR were well below 1 dB at most of the CP region, which show a perfect CP performance. Moreover, the proposed antenna has exhibited a large axial ratio beamwidth in both the xoz- and yoz-planes and a peak gain of 6.1 dBic within the operational bandwidth.
The microstructure evolution and mechanical properties of Mg–10Gd–3Y–xZn–0.6Zr (x = 0.5, 1, and 1.5 wt%) alloys in the as-cast, solution-treated, and peak-aged conditions have been investigated systematically. The results indicate that the microstructure of the as-cast alloy with 0.5% Zn consists of α-Mg, (Mg,Zn)3RE and Mg24(RE,Zn)5 phases, while the alloy with 1.0 and 1.5% Zn consists of α-Mg, (Mg,Zn)3RE and some stacking faults. Moreover, 18R-LPSO phases are observed in the as-cast alloy with 1.5% Zn. The formation of LPSO phases involves not only stacking sequence ordered but also chemical composition ordered. After solution treatment, the Mg24(RE,Zn)5, (Mg,Zn)3RE, stacking faults, and 18R-LPSO phases transform into 14H-LPSO phases. The 14H-LPSO phase plays an important role in the improvement of mechanical properties, especially for the ductility. The β′ phase with a bco structure precipitates in the peak-aged alloys results in precipitation hardening, significantly improving the tensile strength, but it leads to poor ductility.
This study aimed to examine the effectiveness of intratympanic methylprednisolone perfusion as salvage treatment for profound idiopathic sudden sensorineural hearing loss.
A retrospective clinical study of 97 patients with unilateral profound idiopathic sudden sensorineural hearing loss was performed. In all, 83 patients who received salvage intratympanic methylprednisolone perfusion plus conventional treatment (except for steroids) as the second-line therapy were assigned to the study group, while 14 patients who received conventional treatment alone were assigned to the comparison group.
In the study group, treatments in patients with a shorter interval from disease onset to intratympanic methylprednisolone perfusion (up to 15 days) had significantly greater improvements in the overall effective rate and pure tone average compared with patients with a longer interval (over 15 days). For patients with a short interval from disease onset to intratympanic methylprednisolone perfusion, those in the study group had significantly greater improvements in the overall effective rate and pure tone average compared with those in the comparison group. In both the study and comparison groups, hearing improvements were greater at low frequencies than at medium and high frequencies.
The interval from disease onset to intratympanic methylprednisolone perfusion was the major factor affecting hearing recovery. Early second-line salvage intratympanic methylprednisolone perfusion significantly improved the degree of hearing recovery in profound idiopathic sudden sensorineural hearing loss patients after failure of systemic steroid treatment.
Carbon nanotube (CNT) sock formation is required for the continuous synthesis of CNT thread or sheet using the gas phase pyrolysis method. Nanometer diameter CNTs form and are carried along the reactor tube by gas flow. During the flow, the CNT stick to each other and form bundles of about 10-100 nm diameter. Coupling of the CNT bundles in the flow leads to the formation of a centimeter diameter CNT sock with a wall that is hundreds of nanometers thick. Understanding the multiscale phenomena of sock formation is vital for optimizing the CNT synthesis and manufacturing process. In this work, we present a multiscale model for the CNT bundle agglomeration inside a horizontal gas phase pyrolysis reactor. The interaction between CNT bundles was analyzed by representing the attraction forces between CNTs using a discrete phase modeling method. Flow in the synthesis reactor was studied using a computational fluid dynamics (CFD) technique with multiphase flow analysis. A model was proposed to represent the coupling between CNT bundles and the gas flow. The effect of different CNT bundles on the agglomeration phenomenon was analyzed. The modeling results were also compared with experimental observations.
Formation of the carbon nanotube (CNT) sock, which is an assemblage of nanotubes in a thin cylindrical shape, is a prerequisite for continuous production of thread and sheet using the floating catalyst growth method. Although several studies have considered sock formation mechanisms, the dynamics of the sock behavior during the synthesis process are not well understood. In this work, a computational technique is utilized to explore the multiphysics environment within the nanotube reactor affecting the sock formation and structure. Specifically the flow field, temperature profile, catalyst nucleation, and residence time are investigated and their influence on the sock formation and properties are studied. We demonstrate that it is critical to control the multiphysics synthesis environment in order to form a stable sock. Sock production rate was studied experimentally and found to be linearly dependent on the amount of effective catalyst (iron in the sock) inside the reactor. To achieve a high sock production rate, the proportion of effective iron has to be high when increasing the total amount of catalyst in the reactor. Based on the analysis, we suggest that using small size catalyst and growing longer CNTs by increasing temperature, increasing residence times etc. will increase the CNT production rate and improve the properties of CNT thread/sheet produced from the sock.
In this paper, we focus on studying the high energy emission of GRB 160625B. The lightcurve of prompt emission is composed of three episodes: short-soft precursor, hard main burst, and possible long extended emission. The spectra of first and third episode can be fitted by a multi-color blackbody and cutoff power-law model, respectively. However, the spectrum of second episode was contributed by both multi-color blackbody and cutoff power-law. One can estimate the Lorenz factor of jet of first two episodes by invoking photosphere model as Γ0 ~ 175 and 1694, respectively. It suggests that the ejecta of this case evolved from photosphere dominated initially to internal shock later. On the other hand, the optical emission is very bright during the second episode, which is likely a prompt optical emission. Finally, a more shallower normal decay segment appeared, which is consistent with standard external shock model.
The microstructural evolution of spray-formed high speed steel during hot deformation was investigated as well as the effects of spray forming parameters on the porosity formation. Four distinct zones are identified in the as-deposited material, and interstitial porosity is present in the bottom and peripheral zones, while gas-related porosity is mainly found in the central zone. It can keep the porosity at a minimum value by using the optimum parameters, e.g., the average porosity of central zone is 3.7% for a superheat of 170 °C and a gas-to-metal flow rate of 0.7. During hot deformation at 1150 °C, the amount of porosity can be obviously decreased by increasing the height reduction which also plays a key role in breaking up eutectic carbides. The critical height reduction for the breakdown of the eutectic carbides is 50%, the dominant mechanism being mechanical fragmentation.
In the preparation process for scanning electron microscopy (SEM), flexed silkworm embryos typically assume several curled shapes with irregular postures that obscure morphological details during SEM observation. We describe a preparation technique based on glycerol substitution for better SEM visualization of straight and flat silkworm embryos. Glycerol has high viscosity, low vapor pressure, and sufficient electrical conductivity. Silkworm embryos were infiltrated with glycerol and arranged in a straight posture or flattened using a cover slip. Samples were directly observed by SEM without additional dehydration, drying, or coating procedures. The complete ventral side could be easily viewed in one image. Recoating alleviated the charging phenomenon. This represents a simple method for preparation of straight and flat samples from curled biological specimens for SEM observation.
The AlGaN/GaN/InGaN/GaN double heterojunction high electron mobility transistors (DH-HEMTs) sample has been grown by MOCVD on (0 0 0 1) sapphire substrate. The structure features a 7 nm In0.046Ga0.954N interlayer determined by Rutherford backscattering (RBS). Since the polarization field in the InGaN interlayer is opposite to it in the AlGaN layer, an additional potential barrier is introduced between the two-dimensional electron gas (2DEG) channel and buffer, leading to enhanced carrier confinement and improved buffer isolation. The GaN layers between the AlGaN layer and InGaN interlayer are divided into two layers consisting of GaN channel layer which provides high mobility 2DEG grown at 1070 °C and GaN spacer layer grown at the same temperature as InGaN interlayer (800 °C) to prevent indium diffusion. RBS measurement confirms that the 3 nm GaN spacer layer isolates the InGaN interlayer well and free from diffusion. Hall measurement has been performed, the mobility as high as 1552 cm2/V s at room temperature is obtained and the sheet carrier density is 1.55 × 1013 cm−2. The average sheet resistance is 331 Ω/sq, respectively. The mobility obtained in this paper is about 20% higher than similar structures reported.
The system of accretion disk and black hole is usually considered as the central engine of Gamma-ray Bursts (GRBs). It is usually thought that the disk in the central engine of GRBs is the advection-dominated accretion disk, which is developed from a massive (mass Mdisk) torus at radius rdisk. We find a positive correlation between the isotropic gamma-ray energy Eiso and duration (so-called T90) for GRBs. We interpret this correlation within the advection-dominated accretion disk model, associating Eiso and T90 with Mdisk and viscous timescale respectively.
External wrist fixators have been widely used to stabilize distal radial fractures. Ideally an external fixator would create a stable environment for the fracture to heal while allowing proper mobility for the wrist. However, this has been a great challenge to the designers.
The current study aimed to develop a bridging wrist external fixator that is easy for surgeons to create a stable environment for the fracture to heal while allowing proper wrist mobility for rehabilitative purposes. The kinematic geometry of the wrist-fixator system was described using loop equations defined by homogeneous transformation matrices (HTM) of the joints involved, and was evaluated numerically for a set of system parameters that are determined by surgeons during surgery. The results were validated with geometric models and computer simulation. The contributions of individual clinical parameters to the kinematic geometry of the wrist-fixator system were also analyzed using the Taguchi method.
Adequate pin placement and hinge alignment function were found to be critical for the postoperative bridged wrist motion. The results of the current study will be helpful for surgeons to perform fixation using the new wrist fixator and for designers to design new fixators in the future.