Objective To investigate the effects of tirofiban combined with nitroprusside injection through the rapid exchange balloon catheter with self-made side holes on no-reflow (NR)phenomenon during elective percutaneous coronary intervention (PCI).Methods A total of 49 patients with NR phenomenon were randomly divided into the balloon catheter group (n=25)and the guiding catheter group (n=24).Tirofiban combined with nitroprusside were used in both groups.Thrombolysis in myocardial infarction (TIMI)grade and corrected TIMI frame count (CTFC)of target coronary artery at 10 minutes after administration were assessed.Results At 10 minutes after drugs injection,there were 21 (84.0%)patients with target of coronary TIMI 3 grade in the balloon catheter group,and 13 (54.2%)patients in the guiding catheter group.The CTFC was (33.5±12.5)frame in the balloon catheter group,and (41.9±1 5.3)frame in the guiding catheter group.The difference in TIMI and CTFC between the two groups was significantly (P <0.05).Conclusion Injection tirofiban combined with nitroprusside through the rapid exchange balloon cathe-ter with self-made side holes in NR patients during elective PCI might be feasible and effective.

An investigation of inappropriate feeding behavior and its impact was conducted in patents of 875 infants and toddlers aged 1-24 months from March 2004 to February 2008.The survey revealed that inappropriate feeding behavior included feeding sugar solution or sweet fruits daily in 72.1％ parents (631/875) ; adding yolk as the first supplementary food in 51.3％ (394/768) ; not allowing handgrabbing food or coarse food for infants over 7 months in 50.4％ (270/536) and 44.0％ (236/536) ; no meat eating for infants over 12 months in 36.0％ (54/150).And also revealed that 34.0％ (270/795) and 24.8％ (184/743) parents mixed rice flour or yolk with formula milk,respectively; 17.6％ (48/273) infant over 10 months only had cereal; insufficient or excessive water were used for reconstituting milk powder in 11.8％ (87/735) and 9.3％ (68/735),respectively.The results of investigation indicate that inappropriate feeding behavior among infants and toddlers are quite common and the reasons are various.

BACKGROUND:To study the phenotypes of side population cells in leukemia is important for understanding the heterogeneity and origin of tumor cells, molecular markers and targeted therapy.
OBJECTIVE:To identify whether the human chronic myeloid leukemia cellline-K562 contains side population cells or not, and to further observe the differences in expressions of leukocyte differentiation antigens from side population cellsubset and non-side population cells subset.
METHODS:Flow cytometry was used to detect whether there were side population cells in the K562 celllines. Then, the expression of CD34+, CD34+CD38-, CD34+CD38+, HLA-DR+cells in the side population subsets and non-side population subsets.
RESULTS AND CONCLUSION:Flow cytometry results showed that the K562 cellline contained side population cells, and the proportion of side population cells was much lower. The side population cells accounted for (2.7±0.5)%of viable cells in K562. The expressions of CD34+cells and CD34+CD38-cells in the side population subset were significantly higher than those in the non-side population subsets. The expressions of CD34+CD38+cells and HLA-DR+cells in the side population subset and non-side population subset did not have a significant difference. Heterogeneity was found in the differentiation antigen expression between the side population subset and non-side population subset.

Objective To explore rules of changes in velocity of ultrasound wave transmission at the tibia and radius by a quantitative bone mineral density ultrasound scanner in examination of early incipient rickets in infants and its significance in clinical diagnosis.Methods One hundred and fifty-seven infants who visited child health-care clinic of the Capital Institute of Pediatrics,Beijing during May 2004 to December 2007 and clinically diagnosed as rickets according to the Criteria of Diagnosis for Rickets in Infants and Young Children formulated in 1986 by the Ministry of Health,as well as 124 normal healthy infants as controls,were enrolled in the study and followed-up for three months.Velocity of ultrasound wave transmission at the tibia and radius in all the infants were measured by a bone mineral density ultrasound scanner (Sunlight Omnisense 7000R made in Israel).Results One hundred and fifty-seven infants were clinically diagnosed as rickets,127 of them undergone with carpal plane roentgenography and 90 of the 127 with positive change in bone x-ray imaging and 37 without it.Velocity of ultrasound wave transmission at the tibia and radius measured by z-score was significantly lower in infants with clinically diagnosed rickets than that in healthy controls (Z-values of-10.411 and-10.399 at the tibia and-5.646 and-5.517 at the radius,respectively,P = 0.000 with Mann-Whitney test).Velocity of ultrasound wave transmission at the tibia and radius measured by z-score was lower in those with positive change in x-my imaging than that in those without it,but not reaching a level of statistically significant difference.Velocity of ultrasound wave transmission and z-score correlated positively with change in bone x-ray imaging,respectively with Spearman coefficients of correlation of 0.581 and 0.677 for tibia,0.316 and 0.467 for radius (P = 0.000).Receiver operating characteristic (ROC) curve was drawn from those with rickets and positive left carpal plane roetgenograph.Area under curve of ROC for z-score of velocity of ultrasound wave transmission at the tibia was 0.812 and 0.799 (95% CI 0.758-0.856 and 0.742-0.855,P =0.000),respectively.Area under ROC curve of z-score of velocity of ultrasound wave transmission at the radius was 0.715 and 0.697 (95% CI 0.650-0.780,0.631-0.764,P =0.000),respectively.Cut-off value of z-score was-205--1.95 at the tibia,according to the largest sensitivity and the least false-positivity,with sensibility of 0.8 to 0.9 and specificity of 0.733 to 0.702.As its sensitivity at the radius was more than 0.7,its specificity was lower than 0.524.Conclusions Quantitative ultrasound scanning can be used to detect insufficient bone mineral density in infants and their early skeletal change by rickets but without change in bone x-ray imaging.Velocity of ultrasound wave transmission at the tibia can be used as an indicator to predict early rickets in infants rather than its severity.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has spread worldwide and threatened human's health. With the passing of time, the epidemiology of coronavirus disease 2019 evolves and the knowledge of SARS-CoV-2 infection accumu-lates. To further improve the scientific and standardized diagnosis and treatment of maternal SARS-CoV-2 infection in China, the Chinese Society of Perinatal Medicine of Chinese Medical Association commissioned leading experts to develop the Recommendations for the Diagnosis and Treatment of Maternal SARS-CoV-2 Infection under the guidance of the Maternal and Child Health Department of the National Health Commission. This recommendations includes the epidemiology, diagnosis, management, maternal care, medication treatment, care of birth and newborns, and psychological support associated with maternal SARS-CoV-2 infection. It is hoped that the recommendations will effectively help the clinical management of maternal SARS-CoV-2 infection.

Objective:To compare the changes of corneal asphericity and higher-order aberrations after smart pulse technology-assisted transepithelial photorefractive keratectomy (Smart) for low and moderate myopia and to investigate the changes in the shape of the front corneal surface in patients with different diopters.Methods:A non-randomized controlled study design was used.Ninety-eight eyes of 54 patients with moderate or low myopia who underwent Smart surgery in Tianjin Medical University Eye Hospital from November 2018 to March 2019 were included.The 41 eyes of 23 patients with low myopia were set as the low-myopia group, and 57 eyes of 31 patients with moderate myopia were assigned as the moderate-myopia group.The Pentacam anterior segment analysis system was used to measure Q value, index of surface variance (ISV), corneal higher-order aberration (HOA), corneal vertical coma (Z 3-1), corneal horizontal coma (Z 31) and spherical aberration (Z 40) before surgery, 1 month and 3 months after surgery.The anterior surface morphology was compared between the low-myopia and moderate-myopia group.Pearson correlation analysis was used to analyze the correlations between measurement parameters.The study protocol was approved by an Ethics Committee of Tianjin Medical University Eye Hospital (No.2019KY-17). Written informed consent was obtained from each patient before surgery. Results:Corneal Q value, ISV, HOA and Z 40 were 0.445±0.191, 26.973±5.611, 0.671±0.142 and 0.384±0.188, respectively, in the low-myopia group at one month after surgery, which were significantly increased than corresponding preoperative values of -0.273±0.817, 13.784±2.376, 0.433±0.687 and 0.231±0.062 (all at P<0.05). Corneal Q value, ISV, HOA and Z 40 were 0.693±0.203, 34.038±5.773, 0.874±0.216 and 0.520±0.129, respectively, in the moderate-myopia group at one month after surgery, which were significantly increased than corresponding preoperative values of -0.309±0.104, 14.838±3.992, 0.409±0.081 and 0.228±0.089 (all at P<0.05). Corneal Q values, ISV, HOA and Z 40 in the moderate-myopia group were higher than those in the low-myopia group at different time points after surgery, showing significant differences between the two groups (all at P<0.05). There was no significant difference in postoperative 1-month and 3-month corneal Z 3-1 and Z 31 between the two groups (both at P>0.05). The results of correlation analysis showed that there were no significant differences in ΔQ value and ΔISV between the two groups, both of which were negatively correlated with spherical equivalent (ΔQ value: low-myopia group: r=-0.364, P=0.044; moderate-myopia group: r=-0.589, P<0.01; ΔISV: low-myopia group: r=-0.298, P=0.039; moderate-myopia group: r=-0.409, P=0.022). ΔQ value and ΔZ 40 were positively correlated in the moderate-myopia group ( r=0.348, P=0.009); there was no significant correlation between ΔQ value and ΔZ 40 in the low-myopia group ( r=0.180, P=0.266). Conclusions:The corneal high-order aberrations and ISV after Smart are increased in comparison with preoperative values in the low-myopia and moderate-myopia eyes, and the corneal Q values change from negative to positive.The effect of Smart on corneal asphericity is less in the low-myopia eyes.

Corona virus disease 2019 （COVID-19） has led to more than 500 million cases， including 6.19 million deaths. Mutated strains of SARS-CoV-2 （alpha， beta， gamma， delta and omicron） have successively emerged. Currently the omicron variant is gradually replacing the delta variant， driving a surge of cases in most countries including China， posing a great challenge to the prevention and treatment of COVID-19. In the face of the severe pandemic situation， a large number of non-medical volunteers are fighting on the front lines of the war against the pandemic and are vulnerable to exposure due to lack of professional knowledge. This paper introduces the routine skills training of volunteers and emergency response， aiming to provide behavioral guidance for non-medical volunteers in designated isolation facilities.

Self-assembly refers to the spontaneous process where basic units such as molecules and nanostructured materials form a stable and compact structure. Peptides can self-assemble by non-covalent driving forces to form various morphologies such as nanofibers, nano layered structures, and micelles. Peptide self-assembly technology has become a hot research topic in recent years due to the advantages of definite amino acid sequences, easy synthesis and design of peptides. It has been shown that the self-assembly design of certain peptide drugs or the use of self-assembled peptide materials as carriers for drug delivery can solve the problems such as short half-life, poor water solubility and poor penetration due to physiological barrier. This review summarizes the formation mechanism of self-assembled peptides, self-assembly morphology, influencing factors, self-assembly design methods and major applications in biomedical field, providing a reference for the efficient use of peptides.
Pharmaceutical Preparations ; Peptides/chemistry* ; Amino Acid Sequence ; Nanostructures/chemistry* ; Drug Delivery Systems