120 research outputs found
Numerical and Experimental Investigation of Near-Field Mixing in Parallel Dual Round Jets
Parallel underexpanded round jets system has been widely used in engineering applications, and the flow field structures are very complex because of the jets interaction. In this paper, we studied the near-field mixing phenomenon in parallel dual underexpanded jets numerically by solving the Reynolds-Averaged Navier-Stokes Equations. The numerical results agree well with experimental data acquired by particle image velocimetry. Similar to plane jets, to some degree, two round jets are deflected towards the dual nozzle symmetry plane; the flow field can also be divided into three regions. Meanwhile, attempts have been made to predict merge point and combine point locations on certain cross profile of computational domain by correlating them with jet spacing and jet pressure ratio. The jet spacing plays an important role in jets interaction, and jet interaction decreases with the increase in jet spacing. The jets interaction in terms of merge (combine) point and pressure varies significantly while the jet spacing differs. Additionally, as pressure ratio increases, the effect of jet interaction decreases, and the merge (combine) point location moves downstream
Intrauterine ectopic pregnancy — ultrasound typing and treatment
Objectives: To analyze the correlation between ultrasound typing and treatment modality of patients with an intrauterineectopic pregnancy (cervical and cesarean scar).Material and methods: We retrospectively enrolled 65 patients diagnosed with cesarean scar pregnancy (CSP) or cervicalpregnancy (CP) between February 2014 and May 2018. The cases were divided into two types according to the ultrasoundpresentation with a gestational sac (GS, type I) or a heterogeneous mass (HM, type II). Type I was further divided into typeIa (< 8 weeks) and type Ib (≥ 8 weeks); type II was defined as type IIa (with poor or no vascularity) and type IIb (with richvascularity). Three treatment methods were applied in each group.Results: Of included cases, there were 53 CSP and 12 CP. There was no significant difference between Type I and TypeII groups in any variable. The beta human chorionic gonadotropin (β-hCG) level and gestational age of type IIb weresignificantly higher compared to type IIa (p < 0.05). There was a positive correlation between ultrasound categories andtreatment methods (rs = 0.723, p = 0.000). Analysis of CSP cases of initial treatment failure indicated success rate of initialdilation and curettage (D&C) was dependent upon ultrasonic types, mean sac diameter, gestational age, hCG level, andnumber of cesarean sections.Conclusions: The features of ultrasound imaging might provide an additional reference for the selection of clinical treatmentmethods
HumanGen: Generating Human Radiance Fields with Explicit Priors
Recent years have witnessed the tremendous progress of 3D GANs for generating
view-consistent radiance fields with photo-realism. Yet, high-quality
generation of human radiance fields remains challenging, partially due to the
limited human-related priors adopted in existing methods. We present HumanGen,
a novel 3D human generation scheme with detailed geometry and
realistic free-view rendering. It explicitly marries the
3D human generation with various priors from the 2D generator and 3D
reconstructor of humans through the design of "anchor image". We introduce a
hybrid feature representation using the anchor image to bridge the latent space
of HumanGen with the existing 2D generator. We then adopt a pronged design to
disentangle the generation of geometry and appearance. With the aid of the
anchor image, we adapt a 3D reconstructor for fine-grained details synthesis
and propose a two-stage blending scheme to boost appearance generation.
Extensive experiments demonstrate our effectiveness for state-of-the-art 3D
human generation regarding geometry details, texture quality, and free-view
performance. Notably, HumanGen can also incorporate various off-the-shelf 2D
latent editing methods, seamlessly lifting them into 3D
Prevalence and associated factors of depression, anxiety and stress among clinical therapists in China in the context of early COVID-19 pandemic
ObjectivesTo study the socio-demographic characteristics and the prevalence of depression, anxiety, and stress among clinical therapists in China during the early Coronavirus disease 2019 (COVID-19) pandemic and to identify associated factors.MethodThis cross-sectional study was part of a multicenter, nationally representative survey conducted through WeChat from January 2021 to March 2021. Data, including socio-demographics, health-related behaviors, and information on whether they participated in the frontline work of treating COVID-19, were collected anonymously. Respondents also completed the Depression Anxiety Stress Scales-21 (DASS-21).ResultsIn total, 396 clinical therapists in the selected hospitals completed the questionnaires, with a response rate of 89.0%. Respondents were predominantly female (77.3%). About 6.6% of the participants were current tobacco users, and 20.7% had participated in the frontline work of treating COVID-19. Overall, 22.0%, 17.9%, and 8.8% of participants were classified as having clinically meaningful depression, anxiety, and stress, respectively, based on DASS-21 scores. Multiple logistic regression in Model 1 and Model 2 showed that depression, anxiety, and stress were associated with regular physical activity and frequent insomnia (all, p < 0.05). In anxiety model 2, the associated factors for anxiety during the pandemic were identified as education (master’s degree or more, OR=0.520; 95% CI=0.283-0.955), marital status (single, OR=2.064; 95% CI=1.022-4.168), tobacco use (OR=4.265; 95% CI=1.352-13.454), regular physical activity (OR=0.357; 95% CI=0.192-0.663), frequent insomnia (OR=6.298; 95% CI =2.522-15.729), and participation in the frontline work of treating COVID-19 (OR=3.179; 95% CI=1.697-5.954). The COVID-19 epidemic did not significantly increase the depression and stress levels among clinical therapists, but it did significantly increase anxiety levels.ConclusionDuring the COVID-19 pandemic, depression, anxiety and stress were relatively common among clinical therapists in China. Regular physical activity and good sleep were important protective factors against emotional problems. Therefore, encouraging regular physical activity and actively addressing clinical therapists’ sleep problems is beneficial to improving the ability to cope with negative emotions. The COVID-19 epidemic significantly increased anxiety, and awareness and interventions should be recommended to reduce anxiety among clinical therapists during the COVID-19 pandemic
Evaluation of Early Prognostic Factors of Mortality in Patients with Acute Pancreatitis: A Retrospective Study
Early and accurate assessment of severity in acute pancreatitis (AP) is of great importance to provide effective disease management and prevent mortality. In this study, we aim to evaluate early indicators that predict the mortality of AP. We retrospectively analyzed 24-hour clinical characteristics and laboratory data in 166 AP patients recruited between January 2014 and November 2015 in Baotou Central Hospital. In total, 18 patients did not survive the disease. Multivariate logistic regression showed that red cell distribution (RDW) (OR = 2.965, P=0.001) and creatinine (OR = 1.025, P=0.005) were early independent risk factors of AP mortality while albumin (OR = 0.920, P=0.032) levels reduced AP mortality. The corresponding optimal cut-off values were 14.45, 125.5, and 34.95, respectively. The positive predictive values of the AP mortality were 80.1%, 54.5%, and 69.5%. In combined measurement, the area under the curve of RDW, creatinine, and albumin was 0.964 (95% CI: 0.924 to 1.000, P<0.001). RDW ≥ 14.45%, creatinine ≥ 125.5 μmol/l, and albumin ≤ 34.95 g/l indicated a good predictive value for mortality in AP patients with a sensitivity of 100% and specificity of 64.2%. RDW, creatinine, and albumin may serve as early indicators for AP mortality which warrants further clinical investigation
Influence of surface topography on torsional fretting wear under flat-on-flat contact
Influence of surface topography on torsional fretting under flat-on-flat contact were investigated. Contact surfaces of the lower specimens were prepared by milling with different initial surface roughness while the upper specimens were polished. Results indicate that with the increase of surface roughness, friction torque and accumulated dissipated energy present a first increase and then decrease tendency and are higher when the texture is perpendicular to the relative movement direction. The wear volume and wear rate present increasing and decreasing tendencies separately for textures parallel and perpendicular to the relative movement direction, and they are higher when the texture is parallel to the relative movement direction. The results can provide guidance for the initial surface design to reduce fretting wear
Targeted Expression of Cre Recombinase Provokes Placental-Specific DNA Recombination in Transgenic Mice
Background: Inadequate placental development is associated with a high incidence of early embryonic lethality and serious pregnancy disorders in both humans and mice. However, the lack of well-defined trophoblast-specific gene regulatory elements has hampered investigations regarding the role of specific genes in placental development and fetal growth. Principal Findings: By random assembly of placental enhancers from two previously characterized genes, trophoblast specific protein a (Tpbpa) and adenosine deaminase (Ada), we identified a chimeric Tpbpa/Ada enhancer that when combined with the basal Ada promoter provided the highest luciferase activity in cultured human trophoblast cells, in comparison with non-trophoblast cell lines. We used this chimeric enhancer arrangement to drive the expression of a Cre recombinase transgene in the placentas of transgenic mice. Cre transgene expression occurred throughout the placenta but not in maternal organs examined or in the fetus. Significance: In conclusion, we have provided both in vitro and in vivo evidence for a novel genetic system to achieve placental transgene expression by the use of a chimeric Tpbpa/Ada enhancer driven transgene. The availability of thi
PKM2 regulates neural invasion of and predicts poor prognosis for human hilar cholangiocarcinoma
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