Purpose: This study examines the optimal angle for a dual‐field Stanford technique for TSET at extended SSD (SSD= 1, 2, 3, 4, 5 m) to predict a readily available optimal angle for any SSD. Methods: ...The optimal angle at various SSDs is found using detector array. The diode array consists of 9 diodes placed on a vertical board with a measured vertical scale with the origin placed at isocenter. The lateral distance ranges from −100 to +75 cm. A square 36×36 cm2 field is used to deliver dose in HDTSe‐ delivery mode with a dose rate 2500 MU/min from a Varian Clinic 2300IX linac. Several pairs of gantry angles for the dual field are used, with the first gantry being 70°–78° and the second being 110° –102°. These Result in a dual field of 90° ± θ (θ = 10° − 20°) to build a suitable flatness profile on the vertical axis for treatment. The best group is chosen to determine the optimal angle for each SSD considered. From these optimal angles, an algorithm is determined for any extended SSD treatment. Results:It is found that the optimal angle for TSET does change as one varies the SSD. These angle groups are specific for each SSD giving definite markers for the algorithm. At an SSD of 5 m it has been shown that an optimal angle of θ = 106° produces the best flatness on the vertical axis. While at SSD of 4 m, 9 = 18° Conclusions: An algorithm can now be applied for any treatment center considering a dual‐ field Stanford technique for TSET simplifying the physics commissioning process for the center in consideration.
Binary PbTe nanopowders have been successfully synthesized by a reflux method at 100
°C using Pb(CH
3COO)
2 and pure tellurium as the precursors, and NaBH
4 as the reductant. The powders synthesized ...at 100
°C for 48
h are about 100
nm in size. A number of globular particles of about 70
nm with distinct disorder were also observed for the powders synthesized at 100
°C for 24
h. Based on HRTEM observation, we consider that the structure is the intermediate state of the PbTe nanopowders during the synthesis. Possible formation mechanisms of PbTe were also discussed.
Nanostructured materials are of great interest for improving the figure of merit of thermoelectric materials. Single crystalline Bi2Te3 nanowires were prepared by aqueous chemical synthesis at 65 deg ...C using Te as the reactant and sodium-dodecyl-benzene-sulfonate (SDBS) as the surfactant. The products obtained by parallel experiments without the addition of SDBS or using Na2TeO3 as the Te-precursor are very fine nanoparticles without nanowires. It is suggested that the directional effect of SDBS and the dissolving of the amorphous tellurium colloids would be two necessary conditions for the growth of Bi2Te3 nanowires in an aqueous chemical route.
The aim of this study was to evaluate the safety and immunogenicity of the first domestic ACYW135 meningococcal conjugate vaccine and a control vaccine named AC group meningococcal conjugate vaccine ...for 3 months (90-119 days) infants.
From February 2017 to June 2018, a randomized, blinded, and similar vaccine-controlled clinical trial design was adopted at the Henan Vaccine Clinical Research Base. The subjects were 3 months old healthy infants, a total of 720, based on a 1∶1 ratio. The random allocation table for entry was randomly assigned to the experimental group and the control group. According to the 3, 4, and 5 month-old vaccination procedures, the subjects were vaccinated with test vaccine (ACYW135 group meningococcal conjugate vaccine) and control vaccine (group A group C meningococcal polysaccharide conjugate vaccine), of which 720 were given the first dose, 696 were given the second dose (test group: 346; control group: 350), and 692 were given the third dose (test group: 344; Control group: 348).
T
BACKGROUND: Multidrug-resistant tuberculosis is a major threat to the control of tuberculosis and to public health. Whereas most conventional methods of drug susceptibility testing (DST) are precise ...but time consuming, pyrosequencing is a rapid, high-throughput technique.OBJECTIVE:
To conduct a meta-analysis to evaluate the overall accuracy of pyrosequencing for the detection of rifampicin (RMP) resistance.METHODS: We searched PubMed, Web of Science, Elsevier and BIOSIS databases according to a written protocol and explicit study selection criteria. A summary receiver
operating characteristic curve (SROC) and Cochrane (Q*) index were calculated to perform this meta-analysis using Meta-Disc software.RESULTS: Twelve studies involving 594 specimens with RMP resistance and 793 RMP-susceptible specimens met the inclusion criteria. Of these, 11 were based
on Mycobacterium tuberculosis clinical isolates. The overall sensitivity and specificity were estimated at respectively 0.94 (95%CI 0.92-0.96) and 0.98 (95%CI 0.97-0.99). The area under the SROC curve was 0.99 and the Cochrane (Q*) index was 0.96. For clinical specimens,
the overall sensitivity and specificity estimates were respectively 0.89 (range 0.52-1.00) and 0.99 (range 0.95-1.00).CONCLUSIONS: This meta-analysis shows that pyrosequencing is a highly sensitive and specific tool for the detection of RMP resistance in M. tuberculosis.
The pyrosequencing assay is conducted in a high-throughput format, with a turnaround time of <2 h, making it substantially faster than conventional DST methods. We propose that pyrosequencing applied directly to clinical specimens instead of M. tuberculosis isolates could be of greater
clinical value.
We report a significant grain size effect on radiation tolerance of nanocrystalline Mo under He ion irradiation. Irradiation-induced dislocation loops mainly contribute to the irradiation-induced ...hardening of Mo films with grain size of >90nm, while few such loops in those with grain size of <90nm. The hardness increment after irradiation decreases with decreasing the grain size, and approaches zero at the grain size of 25nm. Also, the size and the density of irradiation-induced He bubbles decrease as the grain size decreases. This observation provides direct evidence that nanocrystalline body-centered-cubic metals have greater radiation tolerance than their ultra-fine-grained or coarse-grained counterparts.
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Carbon nanotube (CNT) fiber has not shown its advantage as next-generation light-weight conductor due to the large contact resistance between CNTs, as reflected by its low conductivity and ampacity. ...Coating CNT fiber with a metal layer like Cu has become an effective solution to this problem. However, the weak CNT–Cu interfacial bonding significantly limits the mechanical and electrical performances. Here, we report that a strong CNT–Cu interface can be formed by introducing a Ni nanobuffer layer before depositing the Cu layer. The Ni nanobuffer layer remarkably promotes the load and heat transfer efficiencies between the CNT fiber and Cu layer and improves the quality of the deposited Cu layer. As a result, the new composite fiber with a 2 μm thick Cu layer can exhibit a superhigh effective strength >800 MPa, electrical conductivity >2 × 107 S/m, and ampacity >1 × 105 A/cm2. The composite fiber can also sustain 10 000 times of bending and continuously work for 100 h at 90% ampacity.
To Evaluate the efficacy and safety of posaconazole as primary prevention of invasive fungal disease (IFD) in patients with severe aplastic anemia (SAA) treated with anti-thymus/lymphocyte ...immunoglobulin (ATG/ALG) combined with cyclosporine intensive immunosuppressive therapy (IST).
A retrospective analysis of clinical data of 58 SAA patients who received IST of anti-thymocyte immunoglobulin combining cyclosporine and antifungal prophylaxis during April 2013 to May 2017 in Peking Union Medical College Hospital was performed. The patients were divided into posaconazole prophylaxis group and the control group (itraconazole or fluconazole). The disease characteristics, IFD prevention effect and adverse drug reaction, curative effect and prognosis of the two groups were compared.
Posaconazole was used to prevent fungal infection in 20 patients. The other 38 patients were used as the control group. Retrospective analysis showed comparable characteristics (gender, age, disease severity, etiology, interval between t
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