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The study of enclaves in granitic plutons provides fundamental information on the petrogenesis of their host rocks. Here we combine U–Pb zircon ages, petrography, geochemistry and Nd–Hf isotope composition to investigate the origin of dioritic–granodioritic enclaves and their host granodiorites and biotite granites in the Xuehuading–Panshanchong area, which is a pivotal site to study the Palaeozoic intracontinental orogenic processes of the South China Block. Obtained ages indicate that the host rocks were formed in early Silurian time (c. 432 Ma). The enclaves are fine grained, but with mineral assemblages similar to their hosts and contain amphibole, biotite and plagioclase. All rocks have fractionated rare earth element patterns ((La/Yb)N = 2.86–8.16), except for one biotite granite that has a concave rare earth element pattern ((La/Yb)N = 1.50). Most rocks are depleted in Ta–Nb–Ti, and have negative Eu anomalies and ϵNd(t) (–8.86 to –5.75) and zircon ϵHf(t) (–13.30 to –4.11, except for one, –39.08). We interpret that the enclaves were formed at the borders of magma-ascending conduits, where the mafic mineral crystallization was enhanced by rapid cooling. Conversely, the biotite granites were produced by fractional crystallization from a related granodiorite magma. The sample with a concave rare earth element pattern may have been influenced by hydrothermal fluid–melt interaction. Geochemical modelling suggests that the granodiorites were likely generated by disequilibrium melting of heterogeneous amphibolites in the middle–lower crust. Considering the geological data for the Palaeozoic magmatic rocks in the South China Block, we propose that the Xuehuading–Panshanchong magmatism was likely triggered by piecemeal removal of the thickened lithospheric root and subsequent thermal upwelling of mantle, without a mantle-derived magma contribution to the granites.
Teenagers are important carriers of Neisseria meningitidis, which is a leading cause of invasive meningococcal disease. In China, the carriage rate and risk factors among teenagers are unclear. The present study presents a retrospective analysis of epidemiological data for N. meningitidis carriage from 2013 to 2017 in Suizhou city, China. The carriage rates were 3.26%, 2.22%, 3.33%, 3.53% and 9.88% for 2013, 2014, 2015, 2016 and 2017, respectively. From 2014 to 2017, the carriage rate in the 15- to 19-year-old age group (teenagers) was the highest and significantly higher than that in remain age groups. Subsequently, a larger scale survey (December 2017) for carriage rate and relative risk factors (population density, time spent in the classroom, gender and antibiotics use) were investigated on the teenagers (15- to 19-year-old age) at the same school. The carriage rate was still high at 33.48% (223/663) and varied greatly from 6.56% to 52.94% in a different class. Population density of the classroom was found to be a significant risk factor for carriage, and 1.4 persons/m2 is recommended as the maximum classroom density. Further, higher male gender ratio and more time spent in the classroom were also significantly associated with higher carriage. Finally, antibiotic use was associated with a significantly lower carriage rate. All the results imply that attention should be paid to the teenagers and various measures can be taken to reduce the N. meningitidis carriage, to prevent and control the outbreak of IMD.
Clonorchis sinensis (C. sinensis) is one of the most serious food-borne parasites, which can lead to liver fibrosis or cholangiocarcinoma. Effective measures for clonorchiasis prevention are still urgently needed. Bacillus subtilis (B. subtilis) is an effective antigen delivery platform for oral vaccines. Chonorchis sinensis serpin (CsSerpin) was proved to be potential vaccine candidates. In this study, CsSerpin3 was displayed on the surface of B. subtilis spore and recombinant spores were orally administrated to BALB/C mice. CsSerpin3-specific IgA levels in faecal, bile and intestinal mucous increased at 4–8 weeks after the first administration compared with those in control groups. The mucus production and the number of goblet cells in intestinal mucosa elevated in B.s-CotC-CsSerpin3 (CotC, coat protein of B. subtilis spore) spores treated group compared to those in blank control. No significant difference in the activities of glutamic-pyruvic transaminase/ alanine aminotransferase and glutamic oxalacetic transaminase/aspartate aminotransferase were observed between groups. There was no side effect inflammation and observable pathological damage in the liver tissue of mice after administration. Moreover, collagen deposition and Ishak score were statistically reduced in B.s-CotC-CsSerpin3 spores treated mice. In conclusion, B. subtilis spores displaying CsSerpin3 could be investigated further as an oral vaccine against clonorchiasis.
Dietary salt intake may vary depending on different lifestyles. We aimed to estimate the different salt intakes and evaluate the knowledge and self-awareness about salt among people speaking the Teochew, Teochew–Hakka and Hakka dialects in the Chaoshan region of southern China.
The study followed a cluster sampling of residents in Chaoshan region. General characteristics, lifestyles, health status as well as knowledge and self-awareness related to salt intake were investigated using a questionnaire. Anthropometric variables as well as Na and K excretion in a 24-h urine collection were measured.
Chaoshan region of China.
Four hundred fifteen adults who spoke only one of these three dialects.
The salt intake of adults who spoke the Teochew, Teochew–Hakka and Hakka dialects was 7·19 (interquartile range (IQR) 5·29–10·17), 9·03 (IQR 6·62–11·54) and 10·12 (IQR 7·61–12·82) g/d, respectively, with significant differences between Teochew and Teochew–Hakka speakers and between Teochew and Hakka speakers (both P < 0·05). The Na:K ratio for adults who spoke the three dialects was 3·00 (IQR 2·00–4·11), 3·50 (IQR 2·64–4·82) and 4·52 (IQR 3·35–5·97), respectively, and differed significantly among the groups (all P < 0·05). Multiple linear regression analysis showed increased Na:K ratio associated with hypertension (β = 0·71, P = 0·043) in Hakka speakers. Knowledge and self-awareness about salt intake were poor in this population.
Salt intake was closely related to lifestyles and was higher than the upper limit (5 g/d) recommended by the WHO in adults of Chaoshan, especially those speaking the Hakka dialect.
Recent studies have demonstrated that the nutritional properties of peanut meal (PM) can be improved after being fermented. The assessment of fermented PM has been reported to be limited to various physical and chemical evaluations in vitro. In the present study, PM was fermented by Bacillus natto to explore the effects of fermented PM extract (FE) on growth performance, learning and memory ability and intestinal microflora in mice. Ninety newly weaned male Kunming (KM) mice were randomly divided into seven groups: normal group (n 20), low-dose FE group (n 10), middle-dose FE group (MFE) (n 10), high-dose FE group (HFE) (n 20), unfermented extraction group (n 10), model group (10) and natural recovery group (10). Learning and memory skills were performed by the Morris water maze (MWM) test, and the variation in gut microbiota (GM) composition was assessed by 16S rDNA amplicon sequencing. The results show that HFE remarkably improved the growth performance in mice. In the MWM test, escape latency was shortened in both MFE and HFE groups, while the percentage of time, distance in target quadrant and the number crossing over the platform were significantly increased in the HFE group. Moreover, the FE played a preventive role in the dysbacteriosis of mice induced by antibiotic and increased the richness and species evenness of GM in mice.
Depression often coexists with other chronic conditions in older people. The COACH study is an ongoing random controlled trial (RCT) to test the effectiveness of a primary-care-based collaborative care approach to treat co-morbid hypertension and depression in Chinese rural elders. In the COACH model, a team—village doctor (VD), aging worker (AW), and psychiatrist consultant—provides collaborative care to enrolled subjects in each intervention village for 12 months. This study examines how COACH was implemented and identifies facilitators and barriers for its more widespread implementation.
Five focus groups were conducted, two with VDs, two with AWs, and one with psychiatrists, for a total of 38 participants. Transcripts were analyzed using qualitative content analysis.
COACH care-team members showed shared understanding and appreciation of the team approach and integrated management of hypertension and depression. Team collaboration was smooth. All members regarded COACH to be effective in reducing depressive symptoms and improving patient health. Facilitators to implementation include training, leaders’ support, geographic proximity between VD and AW pairs, preexisting relationships among care-team members, comparability of COACH activities and existing practices of VDs and AWs, and care team members’ caring about older members of their villages. Barriers to sustainability include frustration of some VDs related to their low wages and feelings of overload of some AWs.
COACH was positively perceived and successfully implemented. The findings offer guidance for planning primary-care-based collaborative depression care in low- and middle-income countries.
Needles of Juniperus rigida are used in Chinese traditional medicine for the treatment of brucellosis, dropsy, skin disease, and rheumatoid arthritis. This is the first study that reports anatomical structures of the J. rigida needles collected at different altitudes. The most common anatomical, phytochemical, and histochemical techniques and methods are used. The results show that anatomical structures and chemical composition change significantly at different altitudes. The main anatomical characters are significant xeromorphic structures (thick epidermis, hypodermis, and cuticle), a stomatal band, a developed vascular bundle, and a marginal resin duct. The xeromorphic structures become more pronounced with increasing altitude. The phytochemical and histochemical results demonstrate that the content of the main chemical compounds (phenols and terpenoids) basically increases at a higher elevation. Histochemical analysis localizes the phenols in epidermal cells, sponge tissue, endothelial layer cells, and stomatal bands, and the terpenoids in palisade tissue, sponge tissue, and the edge of the resin duct. This work reveals the relation between anatomy and chemistry in J. rigida needles, contributes to the quality control of its ethno-medicine, and provides the evidence to develop the commercial cultivation.
Previous neuroimaging studies demonstrated that retinal detachment (RD) subjects were associated with abnormal spontaneous brain activities; however, whether the altered interhemispheric functional connectivity (FC) occurred in RD patients remains unknown. The current study tried to explore the alternations of interhemispheric FC of the whole brain in unilateral RD patients using the voxel-mirrored homotopic connectivity (VMHC) method and their connections to clinical features. Methods: We recruited 30 patients with RD (16 males and 14 females) and 30 healthy controls (HCs) (16 males and 14 females) whose age and sex were closely matched. All subjects underwent the rs-fMRI scans. The VMHC method was applied to directly assess the hemispheres’ functional interaction. The VMHC in these brain areas, which could be used as biomarkers to differentiate RD from HC, was identified by the receiver operating characteristic (ROC) curve analyses. The relations between these patients’ clinical features and their mean VMHC signal values in multiple brain regions were calculated by Pearson correlation analysis. Results: RD patients had significantly lower VMHC values than HCs in the bilateral occipital lobe (Brodmann areas, BA 18), bilateral superior temporal gyrus (BA 39), and bilateral cuneus (BA 19). Moreover, the mean VMHC signal values of the bilateral cuneus were in positive correlation with the duration of the RD (r = 0.446, P = 0.013). Conclusion: Our results provided an evidence of disturbed interhemispheric FC in the visual area occurred in RD patients, which might provide some useful information to understand the neural mechanism of RD patients with acute vision loss. Furthermore, the VMHC values might indicate the progress of the RD.
Auto-alignment is a basic technique for high-power laser systems. Special techniques have been developed for laser systems because of their differing structures. This paper describes a new sensor for auto-alignment in a laser system, which can also serve as a reference in certain applications. The authors prove that all of the beam transfer information (position and pointing) can theoretically be monitored and recorded by the sensor. Furthermore, auto-alignment with a single lens sensor is demonstrated on a simple beam line, and the results indicate that effective auto-alignment is achieved.
A facile synthesis procedure of nitrogen-self-doped porous carbon (NPC) derived from abundant natural biological materials has been presented. The pyrolysis temperature and the weight ratio of Co3O4 to carbon play a key role in determining microscopic structure and electrochemical performances of the final materials. The ordered mesostructures with nanopores in the channel walls provided support for immobilization of well-dispersed Co3O4 nanoparticles. They also served as a highly conductive substrate for effectively alleviating severe particle aggregation during the charge/discharge processes, which prevented capacity fading from deteriorated electric contact between the components. Taking advantage of the interconnected porous structures and high specific surface area (1799 m2/g) of carbon substrate, the Co3O4/NPC composite as anode in lithium-ion battery delivers a stable reversible capacity of 903 mA h/g after 400 cycles. It is expected that by loading other electrode active materials on such carbon material, the manufacture of the promising anode materials with excellent cycle stability is highly possible.
The lithium ion battery is the most promising battery candidate to power battery electric vehicles. For these vehicles to be competitive with those powered by conventional internal combustion engines, significant improvements in battery performance are needed, especially in the energy density and power delivery capabilities. Promising substitutes for graphite as the anode material include silicon, tin, germanium, and various metal oxides that have much higher theoretical storage capacities and operated at slightly higher and safer potentials. In this critical review, metal oxides-based materials for lithium ion battery anodes are reviewed in detail together with the progress which is made in my lab on that topic. Their advantages, disadvantages, and performance in lithium ion batteries are discussed through extensive analysis of the literature, and new trends in materials development are also reviewed. Two important future research directions are proposed and performed in my lab, based on results published in the literature: the development of composite and nanostructured metal oxides to overcome the major challenge posed by the high capacity of metal oxide anodes.
Alpha-lipoic acid (ALA) is known to be a natural antioxidant. The aim of the present study was to evaluate the cryoprotective effect of ALA on the motility of boar spermatozoa and its antioxidant effect on boar spermatozoa during freezing–thawing. Different concentrations (2.0, 4.0, 6.0, 8.0 or 10.0 mg/ml) of ALA were added to the extender used to freeze boar semen, and the effects on the quality and endogenous antioxidant enzyme activities of frozen–thawed spermatozoa were assessed. The results indicated that the addition of ALA to the extender resulted in a higher percentage of motile spermatozoa post-thaw (P < 0.05). The activities of superoxide dismutase, lactate dehydrogenase, glutamic-oxaloacetic transaminase and catalase improved after adding ALA to the extender (P < 0.05). Artificial insemination results showed that pregnancy rate and litter size were significantly higher at 6.0 mg/ml in the ALA group than in the control group (P < 0.05). In conclusion, ALA conferred a cryoprotective capacity to the extender used for boar semen during the process of freezing–thawing, and the optimal concentration of ALA for the frozen extender was 6.0 mg/ml.
Large-scale blooms of dinoflagellates, such as Prorocentrum donghaiense and Karenia mikimotoi, have occurred frequently in the East China Sea (ECS) in recent decades. However, little is known about their effects on the entire life history of copepods. Under laboratory conditions, we investigated the effects of these two common dinoflagellates on the survival of Calanus sinicus individuals at different stages and on reproduction of this copepod. Compared with the control treatment (Skeletonema costatum), the presence of P. donghaiense and K. mikimotoi decreased the survival rates of adults and nauplii during the 16 days of the experiment. Survival of nauplii decreased to 49% and 48%, respectively, relative to the nearly 80% survival of adults. Among the six stages of nauplii, individuals at NII and NIII were more susceptible to P. donghaiense and K. mikimotoi. Lower egg production rates were also observed when copepods were exposed to P. donghaiense and K. mikimotoi, and hatching success decreased only with exposure to P. donghaiense. These results suggest that blooms of the two common dinoflagellates may have detrimental effects on the survival of nauplii and the reproduction of C. sinicus, which may pose a major threat to the recruitment of C. sinicus.
In this paper, we propose a biomechatronic design of an anthropomorphic artificial hand that is able to mimic the natural motion of human fingers. The prosthetic hand has 5 fingers and 15 joints, which are actuated by 5 embedded motors. Each finger has three phalanges that can fulfill flexion-extension movements independently. The thumb is specially designed to move along a cone surface when grasping, and the other four fingers are well developed based on the four-bar link mechanism to imitate the motion of the human finger. To accomplish the sophisticated control schemes, the fingers are equipped with numerous torque and position sensors. The mechanical parts, sensors, and motion control systems are integrated in the hand structure, and the motion of the hand can be controlled through electromyography (EMG) signals in real-time. A new concept for the sensory feedback system based on an electrical stimulator is also taken into account. The low-cost prosthetic hand is small in size (85% of the human hand), of low weight (420 g) and has a large grasp power (10 N on the fingertips), hence it has a dexterous and humanlike appearance. The performance of the prosthetic hand is validated in a clinical evaluation on transradial amputees.
Oculocutaneous albinism (OCA) is a heterogeneous autosomal recessive genetic disorder that affects melanin synthesis. OCA results in reduced or absent pigmentation in the hair, skin and eyes. Type 1 OCA (OCA1) is the result of tyrosinase (TYR) gene mutations and is a severe disease type. This study investigated TYR mutations in a Chinese cohort with OCA1. This study included two parts: patient genetic study and prenatal genetic diagnosis. A total of 30 OCA1 patients were subjected to TYR gene mutation analysis. Ten pedigrees were included for prenatal genetic diagnosis. A total of 100 unrelated healthy Chinese individuals were genotyped for controls. The coding sequence and the intron/exon junctions of TYR were analysed by bidirectional DNA sequencing. In this study, 20 mutations were identified, four of which were novel. Of these 30 OCA1 patients, 25 patients were TYR compound heterozygous; two patients carried homozygous TYR mutations; and three were heterozygous. Among the ten prenatally genotyped fetuses, three fetuses carried compound heterozygous mutations and seven carried no mutation or only one mutant allele of TYR and appeared normal at birth. In conclusion, we identified four novel TYR mutations and showed that molecular-based prenatal screening to detect TYR mutations in a fetus at risk for OCA1 provided essential information for genetic counselling of couples at risk.
An ion beam has the unique feature of being able to deposit its main energy inside a human body to kill cancer cells or inside material. However, conventional ion accelerators tend to be huge in size and cost. In this paper, a future intense-laser ion accelerator is discussed to make the laser-based ion accelerator compact and controllable. The issues in the laser ion accelerator include the energy efficiency from the laser to the ions, the ion beam collimation, the ion energy spectrum control, the ion beam bunching, and the ion particle energy control. In the study, each component is designed to control the ion beam quality by particle simulations. The energy efficiency from the laser to ions is improved by using a solid target with a fine sub-wavelength structure or a near-critical-density gas plasma. The ion beam collimation is performed by holes behind the solid target or a multi-layered solid target. The control of the ion energy spectrum and the ion particle energy, and the ion beam bunching are successfully realized by a multi-stage laser–target interaction.
Identification of high-risk regions of schistosomiasis is important for rational resource allocation and effective control strategies. We conducted the first study to apply the newly developed method of adaptive kernel density estimation (KDE)-based spatial relative risk function (sRRF) to detect the high-risk regions of schistosomiasis in the Guichi region of China and compared it with the fixed KDE-based sRRF. We found that the adaptive KDE-based sRRF had a better ability to depict the heterogeneity of risk regions, but was more sensitive to altering the user-defined smoothing parameters. Specifically, the impact of bandwidths on the estimated risk value and risk significance (P value) was higher for the adaptive KDE-based sRRF, but lower on the estimated risk variation standard error (s.e.) compared with the fixed KDE-based sRRF. Based on this application the adaptive and fixed KDE-based sRRF have their respective advantages and disadvantages and the joint application of the two approaches can warrant the best possible identification of high-risk subregions of diseases.
In this paper, we present the use of the orthogonal spline collocation method for the semi-discretization scheme of the one-dimensional coupled nonlinear Schrödinger equations. This method uses the Hermite basis functions, by which physical quantities are approximated with their values and derivatives associated with Gaussian points. The convergence rate with order and the stability of the scheme are proved. Conservation properties are shown in both theory and practice. Extensive numerical experiments are presented to validate the numerical study under consideration.
A preconditioned iterative method for the two-dimensional Helmholtz equation with Robbins boundary conditions is discussed. Using a finite-difference method to discretize the Helmholtz equation leads to a sparse system of equations which is too large to solve directly. The approach taken in this paper is to precondition this linear system with a sine transform based preconditioner and then solve it using the generalized minimum residual method (GMRES). An analytical formula for the eigenvalues of the preconditioned matrix is derived and it is shown that the eigenvalues are clustered around 1 except for some outliers. Numerical results are reported to demonstrate the effectiveness of the proposed method.
The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr64.13Cu15.75Ni10.12Al10 bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.