219 research outputs found

    Effects of Chinese domestic polychlorinated biphenyls (PCBs) on gonadal differentiation in Xenopus laevis.

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    To determine whether polychlorinated biphenyls (PCBs) influence gonadal differentiation in Xenopus laevis, tadpoles were exposed to two Chinese domestic PCBs (PCB3 and PCB5 from Nieuwkoop and Faber stage 46/47 to complete metamorphosis. Gonads were characterized using a dissecting microscope. The control X. laevis had normal ovaries or testes in gross morphology, whereas obviously abnormal testes including ovotestes were found in PCB3- and PCB5-exposed groups. Ovotestes were characterized by morphologic ovaries in the cranial and caudal parts and morphologic testes in the middle part. PCBs did not alter the percentage of females but reduced the percentage of males with morphologically normal testes. The histologic structure of gonads was examined by a series of sections. Morphologically normal and abnormal testes from a few frogs exposed to PCBs were interspersed with oocytes in histologic sections. These testes exhibited looser structure with fewer seminiferous tubes, spermatogonia, and spermatozoa than in controls. The findings suggest that PCB3 and PCB5 have significant feminization effects on gonadal differentiation in X. laevis and that this species is sensitive to endocrine disruption and may be used as a good model to study endocrine disruption

    Curative effect of immediate reconstruction after neoadjuvant chemotherapy for breast cancer: a systematic review and meta-analysis

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    BackgroundThe safety of mastectomy (MT) with immediate reconstruction (IR) in breast cancer patients who have completed neoadjuvant chemotherapy (NAC) is not apparent. This meta-analysis aims to systematically evaluate the differences in surgical complications and postoperative survival rates between MT with IR (MT+IR) and MT alone in post-NAC breast cancer patients.MethodsThe PubMed, Embase, Cochrane Library, WanFang Data, and CNKI databases were systematically searched, and cohort studies of post-NAC breast cancer patients with MT+IR or MT surgery were collected from databases inception to May 25, 2023. Two researchers independently executed literature screening, data extraction, and bias risk assessment, and meta-analysis was performed using Revman 5.3 software.ResultsA total of 12 studies involving 7378 cases who have accepted NAC were collected for this study. The results showed that compared with the MT group, the relative risk of surgical complications in the MT+IR group was increased by 44%, with no statistical significant [RR=1.44, 95% CI (0.99, 2.09), P=0.06]. While among study subgroups with a median follow-up of less than one year, more surgical complications occurred in the MT+IR group by 23% [RR=1.23, 95% CI (1.00, 1.52), P=0.05]. There was no significant differences in overall survival, disease-free survival, local relapse-free survival, and distant metastasis-free survival between the two groups.ConclusionsCompared with the MT, MT+IR does not affect the postoperative survival rate in post-NAC breast cancer patients, accompanied by a mild increase in short-term surgical complications, but no significant difference in long-term complications.Systematic review registrationhttps://www.crd.york.ac.uk/prospero, identifier CRD42023421150

    Ulinastatin attenuates oxidation, inflammation and neural apoptosis in the cerebral cortex of adult rats with ventricular fibrillation after cardiopulmonary resuscitation

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    OBJECTIVE: The role of Ulinastatin in neuronal injury after cardiopulmonary resuscitation has not been elucidated. We aim to evaluate the effects of Ulinastatin on inflammation, oxidation, and neuronal injury in the cerebral cortex after cardiopulmonary resuscitation. METHODS: Ventricular fibrillation was induced in 76 adult male Wistar rats for 6 min, after which cardiopulmonary resuscitation was initiated. After spontaneous circulation returned, the rats were split into two groups: the Ulinastatin 100,000 unit/kg group or the PBS-treated control group. Blood and cerebral cortex samples were obtained and compared at 2, 4, and 8 h after return of spontaneous circulation. The protein levels of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) were assayed using an enzyme-linked immunosorbent assay, and mRNA levels were quantified via real-time polymerase chain reaction. Myeloperoxidase and Malondialdehyde were measured by spectrophotometry. The translocation of nuclear factor-κB p65 was assayed by Western blot. The viable and apoptotic neurons were detected by Nissl and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). RESULTS: Ulinastatin treatment decreased plasma levels of TNF-α and IL-6, expression of mRNA, and Myeloperoxidase and Malondialdehyde in the cerebral cortex. In addition, Ulinastatin attenuated the translocation of nuclear factor-κB p65 at 2, 4, and 8 hours after the return of spontaneous circulation. Ulinastatin increased the number of living neurons and decreased TUNEL-positive neuron numbers in the cortex at 72 h after the return of spontaneous circulation. CONCLUSIONS: Ulinastatin preserved neuronal survival and inhibited neuron apoptosis after the return of spontaneous circulation in Wistar rats via attenuation of the oxidative stress response and translocation of nuclear factor-κB p65 in the cortex. In addition, Ulinastatin decreased the production of TNF-α, IL-6, Myeloperoxidase, and Malondialdehyde

    Geometry and optics calibration of WFCTA prototype telescopes using star light

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    The Large High Altitude Air Shower Observatory project is proposed to study high energy gamma ray astronomy ( 40 GeV-1 PeV ) and cosmic ray physics ( 20 TeV-1 EeV ). The wide field of view Cherenkov telescope array, as a component of the LHAASO project, will be used to study energy spectrum and compositions of cosmic ray by measuring the total Cherenkov light generated by air showers and shower maximum depth. Two prototype telescopes have been in operation since 2008. The pointing accuracy of each telescope is crucial to the direction reconstruction of the primary particles. On the other hand the primary energy reconstruction relies on the shape of the Cherenkov image on the camera and the unrecorded photons due to the imperfect connections between photomultiplier tubes. UV bright stars are used as point-like objects to calibrate the pointing and to study the optical properties of the camera, the spot size and the fractions of unrecorded photons in the insensitive areas of the camera.Comment: 5 pages, 6 figures, submitted to Chinese Physics

    Computed tomography angiography assessment of the degree of simple coarctation of the aorta and its relationship with surgical outcome: A retrospective analysis

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    ObjectiveTo investigate the correlation between the degree of aortic coarctation and surgical prognosis in infants with simple coarctation of the aorta (CoA) using computed tomography angiography (CTA).MethodsThis study was a retrospective study. Twenty-seven infants with simple CoA who underwent surgical correction from January 2020 to June 2022 were enrolled. Aortic diameters were measured at five different levels and normalized to Z scores based on the square root of body surface area. The relevant data were collected and analyzed, and the predictors associated with surgical outcome were determined.ResultsPatients were divided into the mild CoA group and the severe CoA group according to the severity of coarctation. The mechanical ventilation duration and the length of ICU stay in the mild CoA group were significantly lower than those in the severe CoA group. Multiple linear regression analyses revealed that the degree of aortic coarctation was a significant risk factor for a prolonged postoperative ICU stay. In addition, gestational age and age at operation were risk factors for a prolonged postoperative ICU stay. Correlation analysis showed that the degree of aortic coarctation correlated with the Z scores of the ascending aorta and postcoarctation aorta.ConclusionThe degree of the CoA is an important predictor of surgical outcomes in infants with simple CoA and was significantly correlated with the ascending aorta and postcoarctation aorta Z scores. Therefore, preoperative CTA should be routinely performed to assess the degree of aortic coarctation and better identify risk factors

    Photoactive hourglass-type M{P4Mo6}2 networks for efficient removal of hexavalent chromium

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    The exploration of high-efficiency photocatalysts to drive the conversion of highly toxic heavy metal hexavalent chromium (Cr(VI)) in wastewater to low-toxic trivalent chromium (Cr(III)) is of great significance for purifying water that contains emerging contaminants. Herein, four hourglass-type phosphomolybdate-based hybrid networks—(H2bpe)2[M(H2O)3]2{M[P4Mo6O31H7]2}·8H2O (M = Mn for 1, Co for 2) and (Hbpe)(H2bpe)Na[M(H2O)3]2{M[P4Mo6O31H7]2}·9H2O (M = Mn for 3, Co for 4; {M[P4Mo6O31H7]2}8− (abbr. M{P4Mo6}2); bpe = 1,2-di(4-pyridyl)ethylene)—were hydrothermally synthesized as heterogeneous photocatalysts for Cr(VI) reduction. A structural analysis showed that the four hybrids 1–4 exhibited two-dimensional inorganic sheet-like structures with a 3,6-connected kgd topology built of hourglass phosphomolybdate clusters having different central metal ions, which further interacted with organic bpe cations via abundant hydrogen-bonding interactions to extend the structure to a three-dimensional (3D) supramolecular network. The four hybrids displayed excellent redox properties and wide visible-light absorption. When used as heterogeneous photocatalysts, hybrids 1–4 exhibited excellent photocatalytic activity for Cr(VI) reduction under 10 W white light irradiation, with reduction rates of 91% for 1, 74% for 2, 90% for 3, and 71% for 4, respectively, within 80 min. The Cr(VI) reduction reaction over hybrids 1–4 followed the pseudo first-order kinetics model with reaction rate constants k of 0.0237 min−1 for 1, 0.0143 min−1 for 2, 0.0221 min−1 for 3 and 0.0134 min−1 for 4, respectively. The Mn{P4Mo6}2-based hybrids 1 and 3 showed better photocatalytic performance than the Co{P4Mo6}2-based hybrids 2 and 4, along with excellent recycle stability. This mechanism study shows that the different central metals M in the M{P4Mo6}2 cluster have a considerable impact on photocatalytic performance due to their regulation effect on the electronic structure. This work provides evidence for the important role of the central metal in hourglass-type phosphomolybdate in the regulation of photocatalytic performance, and it brings inspiration for the design of highly efficient photocatalysts based on polyoxometalates

    Effect of Walnut Protein on the Quality of Prepared Food

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    China is rich in walnut meal resources, the protein content of walnut meal is high, but it has not been fully utilized. Low fat food is in line with people’s health consumption concept, but it often has some problems such as high hardness, low moisture content, poor taste and flavor. Walnut protein was prepared from walnut meal by appropriate enzymatic hydrolysis technology, and the walnut protein was applied to the processing of prepared food to explore its influence on the quality of prepared food. The results showed that the walnut protein prepared by moderate enzymatic hydrolysis technology could significantly improve the quality and the cooked yield of prepared food. This study can provide technical support and theoretical basis for making full use of walnut meal resources and developing new low-fat conditioning food
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