樟叶提取物作为新型环境友好抑制剂在白钨矿与方解石浮选分离中的应用

采用简单的物理方法,直接榨取樟叶汁液作为白钨矿和方解石分离的抑制剂。通过接触角测量、傅里叶转换红外光谱测试和原子力显微镜研究樟叶提取物中活性成分及其抑制机理。浮选试验表明,樟叶提取物对方解石有较强的抑制作用,对白钨矿的抑制作用较小。原子力显微镜检测证实方解石表面吸附有樟叶提取物的有效成分。红外光谱结果表明,吸附在方解石表面的组分含有大量的羟基,这些羟基使方解石疏水。Zeta电位和红外光谱结果表明,樟树叶提取物在方解石表面的吸附量远大于在白钨矿表面的吸附量。樟叶提取物在白钨矿和方解石浮选分离中具有潜在的应用价值。

Clinical parameters predicting pathologic complete response following neoadjuvant chemoradiotherapy for rectal cancer

Introduction:Preoperative chemoradiotherapy(CRT),followed by total mesorectal excision,has become the standard of care for patients with clinical stages II and III rectal cancer.Patients with pathologic complete response(pCR) to preoperative CRT have been reported to have better outcomes than those without pCR.However,the factors that predict the response to neoadjuvant CRT have not been well defined.In this study,we aimed to investigate the impact of clinical parameters on the development of pCR after neoadjuvant chemoradiation for rectal cancer.Methods:A total of 323 consecutive patients from a single institution who had clinical stage II or III rectal cancer and underwent a long-course neoadjuvant CRT,followed by curative surgery,between 2005 and 2013 were included.Patients were divided into two groups according to their responses to neoadjuvant therapy:the pCR and non-pCR groups.The clinical parameters were analyzed by univariate and multivariate analyses,with pCR as the dependent variable.Results:Of the 323 patients,75(23.2%) achieved pCR.The two groups were comparable in terms of age,sex,body mass index,tumor stage,tumor location,tumor differentiation,radiation dose,and chemotherapy regimen.On multivariate analysis,a pretreatment carcinoembryonic antigen(CEA) level of <5 ng/mL[odds ratio(OR) = 2.170,95%confidence interval(CI) = 1.195-3.939,P = 0.011]and an interval of >7 weeks between the completion of chemoradiation and surgical resection(OR = 2.588,95%CI = 1.484-4.512,P = 0.001) were significantly associated with an increased rate of pCR.Conclusions:The pretreatment CEA level and neoadjuvant chemoradiotherapy-surgery interval were independent clinical predictors for achieving pCR.These results may help clinicians predict the prognosis of patients and develop adaptive treatment strategies.

Hepatic differentiation of rat induced pluripotent stem cells in vitro

AIM: To show the efficient generation of hepatocytelike cells(HLCs) differentiated from the induced pluripotent stem cells(iP SCs) of rats.METHODS: Hepatic differentiation was achieved using a three-step protocol with several growth factors. First, rat i PSCs were differentiated into definitive endoderm cells using Activin A and Wnt3 a treatment. Then fibroblast growth factor 4 and bone morphogenetic protein 2 were added to the culture medium and used to induce hepatic differentiation. Finally, hepatocyte growth factor, Oncostatin M and dexamethasone were used for hepatic maturation. The liver-related markers and functions of HLCs were assessed at the gene and protein levels.RESULTS: After endodermal induction, the differentiated cells expressed endodermal markers forkhead box protein A2 and SRY-box containing gene 17 at the m RNA and protein levels. After 20 d of culture, the i PSCs were differentiated into HLCs. These differentiated cells expressed hepatic markers including α-fetoprotein, albumin CK8, CK18, CK19, and transcription factor HNF-4α. In addition, the cells expressed functional proteins such as α1-antitrypsin, cytochrome P450 1A2 and CYP 3A4. They acted like healthy hepatic cells, storing glycogen and taking up indocyanine green and low-density lipoproteins. Also, the rates of urea synthesis(20 d 1.202 ± 0.080 mg/dL vs 0 d 0.317 ± 0.021 mg/d L, P < 0.01) and albuminsecretion(20 d 1.601 ± 0.102 mg/d L vs 0 d 0.313 ± 0.015 mg/d L, P < 0.01) increased significantly as differentiation progressed.CONCLUSION: Rat i PSCs can differentiate into HLCs rapidly and efficiently. These differentiated cells may be an attractive resource for treatment of end-stage liver disease.

Sedimentology and sequence stratigraphy of the mixed clastic-carbonate deposits in the Late Paleozoic icehouse period:A case study from the northern Qaidam Basin

The widely-developed,mixed clastic-carbonate succession in the northern Qaidam Basin records the paleo-environment changes under the glacial activity during the Late Paleozoic icehouse period in the context of regional tectonic stability,however,the depositional environment and sequence stratigraphy characteristics of the mixed deposits is rarely reported and still not clear.Combined the latest drilling wells data,we analyzed the sedimentary and stratigraphic characterization of the mixed strata via detailed field outcrops and core observations and thin section microscopic observations and recognized three depositional systems,including progradational coastal system,incised valley system,and carbonate-dominated marine shelf system,and identified four third-order sequences,SQ1,SQ2,SQ3 and SQ4,consisting of LST,TST,and HST.The depositional environment is overall belonged to marine-continental transition context and shifted from marine to continental environment frequently,showing an evolutionary pattern from marine towards terrestrial-marine transition and then back into the marine environment again in the long-term,which was controlled by the regional tectonic subsidence and the high-frequency and large-amplitude sea-level changes due to the Late Paleozoic glacial activity.The result is of significance in understanding the evolution of the Qinghai-Tibet Plateau and the sedimentation-climate response.

Thermal analysis of GaN-based laser diode mini-array

Thermal characteristics of multiple laser stripes integrated into one chip is investigated theoretically in this paper. The temperature pattern of the laser diode mini-array packaged in a TO-can is analyzed and optimized to achieve a uniform temperature distribution among the laser stripes and along the cavity direction. The temperature among the laser stripes varies by more than 5 K if the stripes are equally arranged, and can be reduced to less than 0.4 K if proper arrangement is designed. For conventional submount structure, the temperature variation along the cavity direction is as high as 7 K, while for an optimized trapezoid submount structure, the temperature varies only within 0.5 K.

Rapid screening for Klinefelter syndrome with a simple high-resolution melting assay： a multicenter study

Klinefelter syndrome （KS） is the set of symptoms that result from the presence of an extra X chromosome in males. Postnatal population-based KS screening will enable timely diagnosis of this common chromosomal disease, providing the opportunity for early intervention and therapy at the time point when they are most effective and may prevent later symptoms or complications. Therefore, through this study, we introduced a simple high-resolution melting （HRM） assay for KS screening and evaluated its clinical sensitivity and specificity in three medical centers using 1373 clinical blood samples. The HRM assay utilized a single primer pair to simultaneously amplify specific regions in zinc finger protein, X-linked （ZFX） and zinc finger protein, Y-linked （ZFY）. In cases of KS, the ratios of ZFX/ZFYare altered compared to those in normal males. As a result, the specific melting profiles differ and can be differentiated during data analysis. This HRM assay displayed high analytical specificity over a wide range of template DNA amounts （5 ng-50 ng） and reproducibility, high resolution for detecting KS mosaicism, and high clinical sensitivity （100%） and specificity （98.1%）. Moreover, the HRM assay was rapid （2 h per run）, inexpensive （0.2 USD per sample）, easy to perform and automatic, and compatible with both whole blood samples and dried blood spots. Therefore, this HRM assay is an ideal postnatal population-based KS screening tool that can be used for different age groups.