The late-preterm infant refers to the infant who is born at 340/7 through 366/7 week's gestation.In recent years,the number of the late-preterm continually ascends and the proportion of them in the preterm group increase as well.Recent studies find that the rates of morbidity and mortality of late-preterm infants are much higher than those of term infants.The rise of the proportion of the former and the more medical resources consumed attract the considerable attention thereby.In this article,we will review late-preterm infants' morbidity of several systems and its influential factors in order to provide more information for perinatal medical staff to improve diagnosis,treatment and further research.

OBJECTIVE:To establish a method for content determination of dihydroartemisinin in Dihydroartemisinin and piper-aquine phosphate tablets. METHODS:HPLC was performed on the column of Waters YMC-Pack ODS-AQ with mobile phase of acetonitrile-water(gradient elution)at the flow rate of 1.0 ml/min,the detection wavelength was 216 nm,column temperature was 30℃,and injection volume was 20 μl. RESULTS:The linear range of dihydroartemisinin was 0.009 650-1.930 mg/ml(r=0.999 9);RSDs of precision,stability and reproducibility tests were no more than 0.5%;average recovery was 100.76%(RSD=0.95%,n=9). CONCLUSIONS:The method is simple,rapid and accurate,and can be used for the content determination of dihydroartemis-inin in Dihydroartemisinin and piperaquine phosphate tablets.

The formation and progression of tumor is inseparable from the changes of cell cycle regulatory proteins.The G2-M period block effect of tumor cells is especially important in slowing the growth of tumor and improving the curative effect.DNA damage receptor,signal transduction factor and effectors are the classical pathways to mediate G2 phase arrest of tumor cells,and have the potential to be new targets for tumor therapy.

The standardized patient (SP) has been widely used in medical education and clinical training. The teacher-standardized patient (TSP) is played by health providers or medical educators, taking roles as patient, evaluator and teaching guider. The consultation ability of general practitioners includes two aspects: the clinical competency and doctor-patient communication skill. This article reviews the application of TSP in evaluation of consultation ability of general practitioners, focusing on the recruit, training, assessment and application of teacher-standardized patients.

As a new emerging infectious virus, 2019 novel coronavirus (2019-nCoV) has been widely popular all over the world since the beginning of 2020. As a special group, children have similarities and differences with adults for coronavirus disease 2019 (COVID-19) in the epidemiology, diagnosis and treatment, curative effect monitoring, prognosis, virus testing methodology, infection and inflammation markers, etc. This paper mainly reviews the characteristics of COVID-19 in children from two aspects: the epidemiological and pathogenic detection characteristics, so as to provide some basis for its diagnosis and treatment.

Procalcitonin ( PCT) has closely related to the severity of senile pulmonary infection, and its dynamic detection can be used as the auxiliary diagnosis index for elderly severe pneumonia ( SP) . The effects of serum PCT dynamic detection in the early quick identification, diagnosis, disease course monitoring and prognosis evaluation for elderly SP were reviewed, and the effects and clinical significance of the detection in the optimization of antibiotic therapy were also summarized in the paper. The results showed the impor-tant value of PCT dynamic detection in the diagnosis of elderly SP and anti-infection therapy.

The technology,of extracting Semen Cassiae from Jueming Jiangzhi Powder was investigated.The perceutages of extra ction and preservation of anthraquinone were used to select the methods of extra ction, concentration and drying of Semen Cassiae. The optimal procedure was set as follows:the large-size powder of Semen Cassiae was extracted with 50% alcohol for three times, then the extracted liquid was concentrated by vacuum evaporati on and finally dried by spraying.

Objective:To investigate the alveolar bone defects of anterior alveolar bone in patients with bimaxillary protrusion by using cone-beam computed tomography ( CBCT ) . Methods: The samples consisted of 50 patients with bimaxillary protrusion, who were assigned to the teenage group[20 cases, (13. 1 ± 1. 0) years] and adult group[30 cases, (22. 9 ± 4. 2) years] . The adult group included 9 hy-po-divergent, 11 normo-divergent and 10 hyper-divergent patients. The images were obtained by using NewTom VG CBCT and the alveolar defects were evaluated. Results:The ratio of the patients had alveo-lar bone defects was 94. 00%. Meanwhile, the defects were associated with 38. 60% of all the teeth. Most defects occurred on labial alveolar bone ( 98 . 66%); fenestration was found more in the maxillary alveolar region and dehiscence occurred more in the mandible. The dehiscences (3. 06%) and defects prevalence (30. 13%) of the teenage group were significant lower than those of the adult group (11. 73% vs. 42. 46%), P<0. 05; while there was no significance of the fenestrations prevalence between the two group (P>0. 05). The hypo-divergent group had lower fenestrations prevalence (22. 22%) than the normo-divergent (33. 84%) and hyper-divergent groups (37. 50%), P<0. 05. The upper central incisor had the lowest alveolar bone defect prevalence. Conclusion: Alveolar bone defects are common findings in patients with bimaxillary protrusion before orthodontic treatment. The prevalence of defects is affected by age and vertical-growth type.

Mitochondrial DNA (mtDNA) is more susceptible to oxidative damage and has a higher mutation rate compared with nuclear DNA due to the absence of protective histone proteins and imperfect repair system.Somatic alterations in mtDNA have been proposed to contribute to initiation and progression of human cancer in previous researches.However,the role of these mtDNA alterations in gastric cancer progression remains unclear.Point mutations and mtDNA content alterations are the two most common mtDNA alterations that result in mitochondrial dysfunction in gastric cancers.Identifing somatic mtDNA alterations in gastric cancers as well as their association with the clinicopathological parameters of gastric cancer,and exploring the causative factors of the somatic mtDNA alterations in cancer progression have been a new direction of gastric cancer research in recent years.

As one of the treatment options for early stage NSCLC,stereotactic body radiation therapy (SBRT)is mainly applied to the inoperable patients.Compared with small doses of traditional fractionated radi-ation treatment,SBRT are taken a single high dose of radiation.A large body of experience has been accumula-ted over the years and the mathematical model to describe survival in high dose range typically used in SBRT and the best dose of segmentation model were focused on,but there has not yet reached a consensus.Studies show that SBRT has certain advantages in local control ratio and adverse reaction compared with traditional radiotherapy,which can be used in operable patients in the future.