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.
A varactor-based fully reconfigurable microstrip bandpass-to-bandpass-with-embedded-stopband filter is presented in this paper. This filter offers wide center frequency and bandwidth tuning flexibility under both bandpass mode and bandpass-with-embedded-stopband mode. The entire tuning ability is based on multiple mode resonator theory and external quality factor tuning structure for bandpass mode and the introduction of transmission zeros (TZs) for bandpass-with-embedded-stopband mode. Under the bandpass mode, the center frequency tuning range is 0.96–1.45 GHz and the bandwidth can be tuned from 0.09 to 1.41 GHz with a fixed center frequency at 1.22 GHz. Under bandpass-with-embedded-stopband mode, the center frequency and bandwidth can be tuned from 0.94 to 1.61 GHz and 0.2–0.33 GHz, respectively. Good agreements are shown between simulated and measured results.
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.
Northeastern China is a region of high tick abundance, multiple tick-borne pathogens and likely human infections. The spectrum of diseases caused by tick-borne pathogens has not been objectively evaluated in this region for clinical management and for comparison with other regions globally where tick-transmitted diseases are common. Based on clinical symptoms, PCR, indirect immunofluorescent assay and (or) blood smear, we identified and described tick-borne diseases from patients with recent tick bite seen at Mudanjiang Forestry Central Hospital. From May 2010 to September 2011, 42% (75/180) of patients were diagnosed with a specific tick-borne disease, including Lyme borreliosis, tick-borne encephalitis, human granulocytic anaplasmosis, human babesiosis and spotted fever group rickettsiosis. When we compared clinical and laboratory features to identify factors that might discriminate tick-transmitted infections from those lacking that evidence, we revealed that erythema migrans and neurological manifestations were statistically significantly differently presented between those with and without documented aetiologies (P < 0.001, P = 0.003). Twelve patients (6.7%, 12/180) were co-infected with two tick-borne pathogens. We demonstrated the poor ability of clinicians to identify the specific tick-borne disease. In addition, it is necessary to develop specific laboratory assays for optimal diagnosis of tick-borne diseases.
Training students has been proven to be the optimal way to deliver cardiopulmonary resuscitation (CPR) skills. However, it is somehow unknown whether or not the current recommendations appropriate for Caucasian students are also suitable for East Asian students. The purpose of this study is to explore the best age for East Asian students to receive CPR training.
Students were recruited from six schools. Students participated in a standard CPR training program provided by tutors. Each student attended a 60-minute training session with a manikin. After being trained, within one hour, the student’s compression quality was assessed.
A total of 360 students who constituted 12 continuous grades were recruited for this study. Adequate compression depth and satisfactory compression rate with correct hand position could be achieved since the age of 12. However, successful compression rate and complete release could be achieved since the younger age of six.
Current recommendations for Caucasian students to cultivate a full-capacity CPR rescuer at the age of 12 are also appropriate for East Asian students. However, the optimal age for students to receive CPR training should be decided based on evidence and importance assessment of CPR.
He D, Huang K, Yang Y, Jiang W, Yang N, Yang H. What is the optimal age for students to receive cardiopulmonary resuscitation training? Prehosp Disaster Med. 2018;33(4):394–398.
We consider a refracted jump diffusion process having two-sided jumps with rational Laplace transforms. For such a process, by applying a straightforward but interesting approach, we derive formulae for the Laplace transform of its distribution. Our formulae are presented in an attractive form and the approach is novel. In particular, the idea in the application of an approximating procedure is remarkable. In addition, the results are used to price variable annuities with state-dependent fees.
Hot compression tests of a hot isostatically pressed (HIPed) Ni based powder metallurgy (P/M) superalloy were carried out under various combinations of temperatures and strain rates. To bridge the relationship between stresses and strain rates, constitutive equations were established based on a hyperbolic sine Arrhenius equation, which yielded predicted stresses under the test conditions. It was found that the predict values fit the experimental values with good accuracy. Processing maps of the alloy under the test conditions were established; and the corresponding microstructures after test were examined to elaborate the workability of the alloy. It revealed that surface cracks occurred when strain was higher than 0.25, which initiated at the prior powder boundaries (PPBs) and propagated along the boundaries. The optimum hot working parameters for the alloy were proposed to beat the strain rate of 0.014 s−1 and 1075 °C.
To investigate the potential influence of dietary Se intake on mortality among Chinese populations.
We prospectively evaluated all-cause, CVD and cancer mortality risks associated with dietary Se intake in participants of the Shanghai Women’s Health Study (SWHS) and the Shanghai Men’s Health study (SMHS). Dietary Se intake was assessed by validated FFQ during in-person interviews. Cox proportional hazards models were used to calculate hazard ratios (HR) and 95 % CI.
Urban city in China.
Chinese adults (n 133 957).
During an average follow-up of 13·90 years in the SWHS and 8·37 years in the SMHS, 5749 women and 4217 men died. The mean estimated dietary Se intake was 45·48 μg/d for women and 51·34 μg/d for men, respectively. Dietary Se intake was inversely associated with all-cause mortality and CVD mortality in both women and men, with respective HR for the highest compared with the lowest quintile being 0·79 (95 % CI 0·71, 0·88; Ptrend<0·0001) and 0·80 (95 % CI 0·66, 0·98; Ptrend=0·0268) for women, and 0·79 (95 % CI 0·70, 0·89; Ptrend=0·0001) and 0·66 (95 % CI 0·54, 0·82; Ptrend=0·0002) for men. No significant associations were observed for cancer mortality in both women and men. Results were similar in subgroup and sensitivity analyses.
Dietary Se intake was inversely associated with all-cause and cardiovascular mortality in both sexes, but not cancer mortality.
Owing to the difficulty in obtaining mammary gland tissue from lactating animals, it is difficult to test the expression levels of genes in mammary gland. The aim of the current study was to identify if milk fat globule (MFG) in buffalo milk was an alternative to mammary gland (MG) and milk somatic cell (MSC) for gene expression analysis. Six buffalos in late lactation were selected to collect MFG and MSC, and then MG was obtained by surgery. MFG was stained with acridine orange to successfully visualise RNA and several cytoplasmic crescents in MFG. The total RNA in MFG was successfully isolated and the integrity was assessed by agarose gel electrophoresis. We analysed the cellular components in MFG, MG and MSC through testing the expression of cell-specific genes by qRT-PCR. The results showed that adipocyte-specific gene (AdipoQ) and leucocyte-specific genes (CD43, CSF1 and IL1α) in MFG were not detected, whereas epithelial cell marker genes (Keratin 8 and Keratin 18) in MFG were higher than in MSC and lower than in MG, fibroblast marker gene (vimentin) in MFG was significantly lower than in MG and MSC, milk protein genes (LALBA, BLG and CSN2) and milk fat synthesis-related genes (ACC, BTN1A1, FABP3 and FAS) in MFG were higher than in MG and MSC. In conclusion, the total RNA in MFG mainly derives from mammary epithelial cells and can be used to study the functional gene expression of mammary epithelial cells.
To identify important risk factors for recurrent methicillin-resistant Staphylococcus aureus (MRSA) to assist clinicians in identifying high-risk patients for continued surveillance and follow-up.
In this retrospective cohort study, we examined patients with MRSA bacteremia at 122 Veterans Affairs medical facilities from January 1, 2003, through December 31, 2010. Recurrent MRSA bacteremia was identified by a positive blood culture result from 2 to 180 days after index hospitalization discharge. Subset analyses were performed to evaluate risk factors for early-onset (2–60 days after discharge) and late-onset (61–180 days after discharge) recurrence. Risk factors were evaluated using Cox proportional hazards regression.
Of 18,425 patients, 1,159 (6.3%) had recurrent MRSA bacteremia. The median time to recurrence was 63 days. Longer duration of index bacteremia, increased severity of illness, receipt of only vancomycin, community-acquired infection, and several comorbidities were risk factors for recurrence. Congestive heart failure, hypertension, and rheumatoid arthritis/collagen disease were risk factors for early-onset but not late-onset recurrence. Geographic region and cardiac arrhythmias were risk factors for late-onset but not early-onset recurrence.
Risk factors for recurrent MRSA bacteremia included comorbidities, severity of illness, duration of bacteremia, and receipt of only vancomycin. Awareness of risk factors may be important at patient discharge for implementation of quality improvement initiatives including surveillance, follow-up, and education for high-risk patients.
Severe fever with thrombocytopenia syndrome virus (SFTSV) has been prevalent for some time in China and it was first identified in 2010. However, the seroprevalence of SFTSV in the general population in southeastern China and risk factors associated with the infection are currently unclear. Blood samples were collected from seven counties across Zhejiang province and tested for the presence of SFTSV-specific IgG antibodies by ELISA. A total of 1380 blood samples were collected of which 5·51% were seropositive for SFTSV with seroprevalence varying significantly between sites. Seroprevalence of SFTSV in people who were family members of the patient, lived in the same village as the patient, or lived in a different village than the patient varied significantly. There was significant difference in seroprevalence between participants who bred domestic animals and participants who did not. Domestic animals are probably potential reservoir hosts and contact with domestic animals may be a transmission route of SFTSV.
Due to its outstanding properties, diamond is considered as an ideal material for mechanical and electric applications at high temperatures, voltages, radiation, etc. It is known that femtosecond lasers exhibit extremely high precision and minimized thermal effect in material processing. In this study, a seed-free diamond pattern growth method was developed by patterning silicon substrates using a femtosecond laser before diamond deposition through laser-assisted combustion flame synthesis. The resolution of the diamond patterns reaches micro scales. Peak position, full width at half maximum (FWHM), and diamond quality parameter were calculated from Raman spectra. The mechanism of the seed-free diamond growth based on the femtosecond laser patterning was discussed. The influence of substrates surface roughness on the diamond nucleation and subsequent growth was studied, indicating that the nucleation density is proportional to the surface roughness.
A femtosecond (fs) pulse duration is shorter than many physical/chemical characteristic times, such as the electron-photon relaxation time, which makes it possible to control electron dynamics. This paper reviews our recent progress which proposes to change electron dynamics (selective excitation/ionization) and electron densities/temperatures in materials to control the following properties and processes: 1) the transient (femtosecond-to-picosecond time scale), localized (nanometer-to-micrometer length scale) material properties, 2) the corresponding photon absorption process, and 3) phase change mechanisms, by manipulating fs pulse-train number/delay for high-precision micro/nanoscale manufacturing.
Pb(Sc1/2Ta1/2)O3 (PST) relaxor ferroelectric ceramics were investigated widely in the past decades for their excellent pyroelectric, ferroelectric and dielectric properties and comprehensive applications in uncooled focal plane arrays infrared detectors and other electronic devices. However, some other ferroelectrics could be added into the PST ceramics to form the complex perovskite ferroelectrics with better electric properties. In this paper, (1-x)PST-xPZT(PSTZT) relaxor ferroelectric ceramics were prepared by wolframite precursor process (named two-step -sintering method, TSSM). The experiment results showed that the PSTZT ceramics with pure perovskite structure could be prepared by using TSSM. The temperature dependence of permittivity and dielectric loss of PSTZT ceramics were investigated in detail, which indicated that PSTZT ceramics showed partly diffusive phase transition with little frequency dispersion. The dielectric and pyroelectric properties of PSTZT ceramics were also investigated and discussed.
Two suites of granitoids, the Late Jurassic (158 ± 3 Ma) Linglong suite and the Early Cretaceous (130–126 Ma) Guojialing suite, crop out in the northwestern Jiaodong Peninsula, eastern China. The Linglong suite is a monzogranite, comprising alkali feldspar, plagioclase, quartz and Fe-rich biotite. The Guojialing suite includes at least five plutonic bodies of both granodiorite and monzo-granite. The rocks are composed of plagioclase, alkali feldspar, quartz, Mg-rich amphibole and Mg-rich biotite. Both the Linglong and Guojialing suites have adakitic affinity. They are enriched in LREE with high La/Yb ratios and show positive Eu anomalies. The rocks are also enriched in LILE and depleted in HFSE with high Sr/Y ratios. The Linglong granite shows very uniform Sr–Nd isotopic compositions with initial 87Sr/86Sr ratios of 0.7119–0.7126 and εNd (T) values of −21.3 to −21.6, which are similar to those of the local Neoarchaean basement. The Guojialing suite has variable initial 87Sr/86Sr ratios (0.7108–0.7120) and εNd (T) values (−10.8 to −17.2), which are distinct both from those of the Neoarchaean basement and from those of the local enriched lithospheric mantle inferred from the coeval mafic dykes in the studied area. Detailed petrological and geochemical data indicate that the Linglong suite was derived by partial melting of Neoarchaean metamorphic lower-crustal rocks at depth of > 50 km with a eclogite residue, whereas the Guojialing suite was formed by the reaction of delaminated eclogitic crust-derived melt with the upwelling asthenospheric mantle. The petrogenesis of these two contrasting adakitic granitoids suggests intensive lower-crustal delamination during Early Cretaceous times, following a crustal thickening process from the late stage of the Early Jurassic to early stage of the Late Jurassic with crustal thickness of < 32 km to > 50 km, respectively.
To evaluate the effects of H5 subtype avian influenza DNA vaccine with HA gene and expressive vector optimization, groups of 3-week-old specific pathogen free (SPF) chickens were inoculated intramuscularly with a single dose of 100 μg or 10 μg of pCIHA5, pCAGGHA5, pCIoptiHA5 or pCAGGoptiHA5 in 200 μl volume. Another group of chickens was injected with 200 μl phosphate-buffered saline (PBS) as controls. Sera were collected every week after vaccination to detect the HI and agar-gel precipitin (AGP) antibodies. Four weeks after the single vaccination, all chickens were challenged with 100LD50 of the highly pathogenic A/Goose/GuangDong/1/96(H5N1) [Gs/GD/1/96(H5N1)]. Oropharyngeal and cloacal swab specimens were collected from all chickens 3, 5 and 7 days after inoculation for titration of virus in eggs. Chickens were observed daily for 2 weeks for signs of disease and death. Results showed that in the groups vaccinated with 100 μg pCAGGoptiHA5 and pCAGGHA5 chickens were completely protected from virus challenge (no disease signs, no virus shedding and no deaths), while only partial protection occurred in chickens vaccinated with 100 μg pCIoptiHA5 (75%) and pCIHA5 (50%). In groups vaccinated with 10 μg pCAGGoptiHA5 and pCAGGHA5 chickens were protected from virus challenge (no disease signs and no deaths). In the group vaccinated with 10 μg pCIoptiHA5 the protection ratio was 75%, while chickens vaccinated with 10 μg pCIHA5 all died after challenge. Results indicated that codon usage optimization of the HA gene and β-actin promoter enhanced the protection efficiency of H5 subtype avian influenza DNA vaccine and the construction pCAGGoptiHA5 could protect chickens from lethal H5N1 virus challenge even at the low dose of 10 μg, implying the possibility for the commercialization of an avian influenza DNA vaccine in the near future.
Radiation transfer in low-density foam is influenced by the external
radiation field which impacts on the foam when the size of plasma created
in laboratory is not large to be opatical thick. The radiation transfers
of different photon groups are sensitive probes of the conditions of the
medium through which they propagate. The temporal behavior of photon
groups to which the plasma is optical thin is quite different from that of
photon groups to which the plasma is optical thick. The breakout times of
different photon groups through the foam are distinguishable different in
experiment when we measures them at the end of foam. The multi-group
supersonic radiation transfer behavior in low-density foam is studied both
by multi-group transfer numerical simulation and experiments. Two
characteristic photon groups are chosen to do experimental research on the
multi-group transfer behavior in low-density CH foam. A time-resolved
chromatic streaked X-ray spectrometer measure the breakout of the two
photon group from the far end of the foam cylinder. The distinguishable
transfer time delay between two groups is observed.
The structure of a new iodate, (LiFe1/3)(IO3)2, has been determined. The new compound has a hexagonal structure with the lattice parameters a=5.4632(2) Å, c=5.0895(6) Å, Z=1. The density is 4.70 g cm−3. Rietveld refinement confirms that the compound has a space group of P63 (173). Fe and Li atoms randomly distribute on the 2a cation site.
Email your librarian or administrator to recommend adding this to your organisation's collection.