A new type of piezoelectric oscillation-based non-contact spotting mode has been developed to overcome the disadvantages of traditional non-contact spotting modes including complicated operation procedure, cleaning difficulty of spotting needle, large sample consumption of electromagnetic microvalve and high spotting cost of piezoelectric inkjet based non-contact spotting mode. In the device, the capillary spotting needle and the piezoelectric driving device are two independent units used for replacing and cleaning capillary spotting needle. The glass capillary spotting needle is prepared by the laser melting method with adjustable diameter and low cost. The sample spotting volume of the device can be easily adjusted in the range of 10Symbolm_10-10Symbolm_9 by changing the amplitude and frequency of piezoelectric ceramic. A microarray spotting system is developed by the combination of the piezoelectric oscillation-based non-contact spotting mode and three dimensional precision displacement control technology. The multiple parameters of as-prepared microarray spotting system have been tested including spotting volume, density of spot and spotting precision. The experimental results indicate that the minimum volume of single spot with 320 pL and the highest density of spot with 4000 spots/cm2 can be achieved by the as-prepared microarray spotting system. Furthermore, the as-prepared microarray spotting system can also be employed to fabricate patterned interface.

Objective To study the colonization rate and antibiotic resistance of group B Streptococcus (GBS) in gravidas during late pregnancy,and to evaluate the effectiveness of GBS screening in late pregnancy and intrapartum antibiotic prophylaxis (IAP) for the prevention of neonatal early-onset GBS disease (EOGBS).Methods A retrospective study was conducted to analyze the colonization rate and antibiotic resistance pattern of GBS in 14 204 gravidas who were screened for GBS at 35-37 gestational weeks during March 2016 to March 2018 in the University of Hongkong-Shenzhen Hospital (HKU-SZH).Differences in the incidence of EOGBS before and after GBS screening and IAP were analyzed using Chi-square or Fisher's exact test.Results Among the 14 204 gravidas,2 027 cases were GBS positive with a colonization rate of 14.27％.Incidence rates of EOGBS before and after GBS screening were 0.6‰ (4/6 356) and 0.07‰ (1/14 403),respectively (Fisher's exact test,P=0.033).GBS isolates were 100％ (2 027/2 027) sensitive to penicillin and vancomycin.Resistance rates to clindamycin and erythromycin were 67.2％(1 363/2 027) and 65.7％ (1 332/2 027),respectively.Conclusions Routine GBS screening in late pregnancy and IAP can significantly decrease the incidence of EOGBS.Penicillin is the optimal choice for prevention and treatment of GBS infection.

Enhanced Recovery After Surgery (ERAS) has been well-accepted and popularized in many surgeries but not in the field of trauma orthopaedics except in senile hip fractures for which relatively fast progress has been made in ERAS.Senile hip fractures have been regarded as important as stroke and myocardial infarction in discussion of emergency management due to tremendously changed understanding of the injury in the elderly,indicating the importance of ERAS for this population.The key point to ERAS for senile hip fractures is to optimizing peri-operative management so as to reduce surgical risks,improve surgical safety and enhance patients' satisfaction.The optimal peri-operative management involves proper surgical timing,nutritional support,management of pain and sleep,prevention of infection and venous thromboembolism,optimal application of drainage tubes and urinary catheters,and functional rehabilitation as well.This article reviews the literature concerning peri-operative management of senile hip fractures in the light of ERAS,and summarizes the strategies for the peri-operative management for the elderly patients.

Objective:To investigate the feasibility of reducing radiation dose in coronary CT angiography for patients with arrhythmia with absolute phase and narrow window in prospective electrocardiogram-gating.Methods:200 patients with arrhythmia underwent coronary CT angiography procedure with prospective electrocardiogram-gating adaptive sequence in dual source CT were randomly divided into 2 groups according to the scan mode. Group A was scanned with absolute phase and narrow window(250-450 ms) and group B uesd relative phase and wide window (30%-75%). The other parameters and injection protocol of contrast media were the same in 2 groups. Both image quality and radiation dose of the 2 groups were analyzed.Results:No significant difference of image quality was found between the 2 groups. CTDI vol, DLP, E of group A were all lower than those in group B [CTDI vol : (16.71±8.35) vs.(29.35±17.90)mGy , DLP: (231.04±114.86) vs.(398.27±238.40)mGy·cm , E: (3.23±1.60) vs.(5.57±3.33)mSv, t=-6.40, -6.32、-6.32, P<0.05] . The patients with repeat scan cycles in group A and group B were 81 vs. 22 for 0 cycle , 17 vs. 62 for 1 cycle, 2 vs. 10 for 2 cycles, 0 vs. 6 for 3 cycles( χ2=70.76, P<0.05). Conclusions:The prospective electrocardiogram-gating adaptive CCTA sequence with absolute phase and narrow window can reduce radiation dose while the image quality meets the requirementsfor patients with arrhythmia.

HMG-CoA reductase (HMGCR) protein is usually upregulated after statin (HMGCR inhibitor) treatment, which inevitably diminishes its therapeutic efficacy, provoking the need for higher doses associated with adverse effects. The proteolysis targeting chimera (PROTAC) technology has recently emerged as a powerful approach for inducing protein degradation. Nonetheless, due to their bifunctional nature, developing orally bioavailable PROTACs remains a great challenge. Herein, we identified a powerful HMGCR-targeted PROTAC (