1.Determination of Three Pyrethroids in Soil by Matrix Solid Phase Dispersion Extraction_Dispersed Liquid Phase Microextraction_Gas Chromatography Mass Spectrometry
Hao CHENG ; Lijun ZHANG ; Lei ZHANG ; Zhanen ZHANG
Chinese Journal of Analytical Chemistry 2015;(1):137-140
A matrix solid phase dispersion extraction_dispersed liquid phase microextraction_gas chromatography_mass spectrometric method has been developed for the determination of three pyrethroids ( tetramethrin, permethrin and deltamethrin) in soil. The optimal conditions for the analysis were as follows. About 0. 5 g soil and 1. 5 g C18 solid phase extraction powder were grinding for 5 min. The mixture was eluted with 10 mL of acetone. The eluent was concentrated to 0. 4 mL, and then mixed with 20 μL of tetrachloromethane and 5. 0 mL of ultrapure water to form a homogeneous cloudy solution. The emulsion was broken by centrifugation. About 1 μL of sediment was injected and analyzed directly by GC_MS. Good linearities for three pyrethroids were ranged from 5 to 200 μg/kg (r2≥0. 9989), and recoveries at three spiked levels were ranged from 86 . 5% to 108 . 0% with RSDs less than 7 . 8%. The LODs of three pyrethroids were 1. 00-1. 48 μg/kg. This method can meet the determination of trace pyrethroids in soil.
2.Relationship and conversion between persisters and antimicrobial resistant bacteria
Hao LI ; Lei CHENG ; Xuedong ZHOU ; Biao REN
Chinese Journal of Microbiology and Immunology 2017;37(8):628-633
Persisters are a sub-population of bacteria that can survive lethal concentrations of antibiotics.They contribute to recurrent or intractable chronic infections.Persisters can emerge as a result of multiple mechanisms which lead to drug tolerance.Unlike antimicrobial resistance which usually acquires genetic mutation, phenotypes of persisters are non-inheritable.Despite the distinct difference between persistence and resistance, recent studies have demonstrated that not only persistence can be observed in resistant mutants, but also persisters themselves can be regarded as an intermediate state which promotes the emergence of resistance.This review focuses on mechanisms of drug tolerance in persisters, phenomena of persistence in antimicrobial resistant bacteria and possible mechanisms of the conversion of persisters to resistant bacteria.Moreover, future research directions are also prospected is this review.
3.Comparison of the clinical efficacy between two kinds of ceramic veneer restoration
Run CHEN ; Lei JIANG ; Hao YU ; Ming ZHENG ; Hui CHENG
Journal of Practical Stomatology 2016;32(4):542-546
Objective:To evaluate the clinical efficacy between preparation porcelain veneer(PPV)and no-preparation porcelain veneer(NPPV).Methods:44 patients with 97 PPVs and 23 patients with 57 NPPVs were followed up for 3 years.Mental tension, postoperative dentin sensitivity and satisfaction of the patients,survival rate of the veneers,sulcus bleeding index(SBI)of preopera-tive and postoperative 3 years were evaluated.A comparative analysis was taken to examine the clinical indicators of 2 groups accord-ing to the modified CDA /Ryge criteria.Results:Survival rates of PPVs and NPPVs were 96.91 % and 96.49%(P >0.05),satisfac-tion rates of the 2 group patients were 95.45% and 95.65%(P >0.05),respectively.Mental tension and the postoperative dentin sensitivity of patients in PPV group was higher than those in NPPV group.Preoperative and postoperative SBI were not statistically dif-ferent between the 2 groups(P >0.05).Marginal adaptation in PPV group was better than that in NPPV group.Color matching, Porcelain surface and Marginal stain were not statistically different between 2 groups.Conclusion:Preparation porcelain veneers and no-preparation porcelain veneers both are effective in clinical application.
4.Influential factors and preventive measures for postoperative surgical site infection
Yingying WANG ; Guyan WANG ; Jun LI ; Lei WANG ; Hao CHENG
Chinese Journal of Anesthesiology 2021;41(2):142-148
Postoperative surgical site infection (SSI) can lead to adverse clinical outcomes in patients, such as prolonged hospital stay, increased medical costs, and severe economic burden on patients and on society.In addition, it may also cause nosocomial cross-infection.Therefore, it has aroused the high attention of medical workers.The development of SSI is closely related to a variety of factors, including patient factors, such as blood glucose levels, smoking, systemic use of steroids, obesity and malnutrition, and perioperative related factors, such as long preoperative hospital stay, preoperative skin preparation and prophylactic use of antibiotics of patients, hand hygiene and asepsis principles of medical staff, operation-related factors, anesthetic management and operation related factors, operating room environment factors and postoperative factors.Through reading a large number of relevant literatures published in recent years and according to the work characteristics of anesthesiologists, the author summarized the influential factors and preventive measures for postoperative SSI for the reference of fellow doctors.
5.Comparison of Rhizosphere Bacteria Diversity Between Fusarium Wilt Resistant and Susceptible Watermelon
Juan-Li LEI ; Wei-Song SHOU ; Wen-Qi DONG ; Zhi-Hao XU ; Cheng-Hao ZHANG ;
Microbiology 2008;0(12):-
The traditional culture methods and the molecular biology methods were used to study the rhizosphere bacterial diversity between fusarium wilt resistant and susceptible watermelon. The results showed that the diversity and the equality of cultured rhizosphere bacteria of resistant watermelon were higher than those of the susceptible watermelon. The reason was that the cultured rhizosphere bacterial di- versity index H′ and 1/D of the resistant watermelon were higher than those of the susceptible watermelon and that the cultured rhizosphere bacterial equality index E of the resistant watermelon were higher than those of the susceptible watermelon. The dominant cultured bacterial genotypes were different between re- sistant and susceptible watermelon. The genotype 1 is the dominant genotype of resistant watermelon, con- sists 51.1%. The genotype 7 is the dominant genotype of susceptible watermelon, consists 58.7%.
6.Middle and long-term results of total hip arthroplasties for secondary post-traumatic arthritis and femoral head necrosis after acetabular fractures.
Lei YU ; Cheng-huan ZHANG ; Ting GUO ; Hao DING ; Jian-ning ZHAO
China Journal of Orthopaedics and Traumatology 2016;29(2):109-113
OBJECTIVETo evaluate middle and long-term results of total hip arthroplasties (THA) for the treatment of secondary hip traumatic osteoarthritis and femoral head necrosis after acetabular fractures.
METHODSFrom January 2000 to December 2005, 33 patients with secondary hip traumatic osteoarthritis and (or) femoral head necrosis after acetabular fractures were treated with THA. There were 21 males and 12 females, ranging in age from 27 to 69 years old, with an average of 52 years old. Twenty-three patients were performed with open reduction and internal fixation: 5 patients were treated with anterior approach; 12 patients, posterior approach; 6 patients, combined approaches; other 10 patients, conservative treatment in the early stage. All THA were performed with posterior-lateral approach. Bone union was achieved in the all acetabular fractures. Removal of all implants was necessary in 5 patients, and partial removal in 3 patients. Cemented cup was implanted in 6 patients and uncommented cup in 27 patients. Intraoperative and postoperative complications were observed, and Harris hip scores before surgery and 10 years after operation were compared. The prosthetic loosening, osteolysis or revision were used to evaluate 10 years survival rate of prosthesis.
RESULTSAll the patients were followed up,and the duration ranged from 10 to 15 years, with a mean of 12 years. One patient died at the 10th year after operation. The Harris score at the 10th year was higher than the preoperative one. One and two patients were performed with revision total hip arthroplasty caused by aseptic loosening alone and aseptic loosening combined with osteolysis respectively. Osteolysis occurred in 1 patient; deep venous thrombosis in 4 patients; dislocation of prosthesis in 2 patients. One patient had infection of incision and one patient had infection around the prosthesis. Ten years survival rate of implant was 84.8% (28/133).
CONCLUSIONTHA is an effective method to treat secondary hip traumatic osteoarthritis and (or) femoral head necrosis after acetabular fractures in improving hip joint functions with high implant survival rate and good middle and long-term results.
Acetabulum ; injuries ; Adult ; Aged ; Arthroplasty, Replacement, Hip ; methods ; Female ; Femur Head Necrosis ; surgery ; Fractures, Bone ; complications ; Hip Injuries ; complications ; Humans ; Male ; Middle Aged ; Osteoarthritis, Hip ; surgery ; Postoperative Complications ; surgery
7.Clinical research of needle-pricking therapy for functional retrograde ejaculatioin.
Dong CHENG ; Lei HU ; Feng XIAN ; Jian ZHONG ; Yuejuan ZHANG ; Gangwei WANG ; Jiyuan MA ; Hao XU
Chinese Acupuncture & Moxibustion 2016;36(2):153-156
OBJECTIVETo observe the clinical effects of needle-pricking therapy, a newly medical and minimally invasive technique, for functional retrograde ejaculation and to explore its mechanism. Methods Thirty-six patients with functional retrograde ejaculation were randomly divided into an observation group(19 cases) and a control group(17 cases) In the observation group,needle-pricking therapy was used at Guanyuan(CV 4) and bilateral sacral plexus nerve,lumbar 1 nerve and greater occipital nerve stimulating points,once a week. In the control group, midodrine tablets were prescribed orally,three times a day. All the treatment was given for 9 weeks. The clinical effects of the two groups were observed, and the levels of luteinizing hormone(LH), testosterone(Tes) and estra4 diol(E2) were compared between the two groups.
RESULTSThe total effective rate of the observation group was, 89. 47%(17/19), which was better than 47.06% (8/17) of the control group(P<0. 05). The LH and Tes were obviously increased and E2 was decreased compared with those before treatment in the observation group(all P< 0. 01). Tes was raised(P<0. 05) and E2 was apparently declined in the control group(P<0. 01). After treatment, the differences of serum LH and Tes were statistically significant between the two groups(both P<0. 01).
CONCLUSIONNeedle-pricking therapy has advantages for functional retrograde ejaculation probably in that stimulating lumbosacral nerves can strengthen the function of pelvic floor muscles and urethral expansion muscle and regulate sexual gland axis.
Acupuncture Points ; Acupuncture Therapy ; Adult ; Ejaculation ; Humans ; Male ; Middle Aged ; Needles ; Sexual Dysfunction, Physiological ; physiopathology ; therapy ; Treatment Outcome
8.The location and proliferation of human hair follicle stem cells
Lei ZHANG ; Bo CHENG ; Yue MAI ; Xiaoyong JIANG ; Peiying PAN ; Fei HAO
Chinese Journal of Dermatology 1995;0(03):-
Objective To investigate the location and proliferation of human hair follicle stem cells. Methods The expression of keratin 19(K19) in the human hair follicles on the occiput was detected by immunohistochemical staining, and the positive area was located. The follicle epithelium containing the K19-positive area above the hair bulb were cultured with or without mesenchymes (dermal papilla cells, DPCs) at the air-liquid interface of the collagen gel. When the proliferating colonies formed, the distance from the colony to the bottom of hair follicles was measured and the relationship between the K19-positive position and the proliferation colonies was analyzed. The ultrastructure of the proliferation colony was observed by transmission electron microscopy. Results Two portions were found positive for K19 in the outer root sheath of the human hair follicles, the upper one being at the bulge region and the lower one at the outer root sheath above the hair bulb. The proliferating colony formed only when the epithelium of the hair follicle was co-cultured with mesenchymes cells. The statistical analysis suggested the lower portion positive for K19 and the proliferation colonies in the culture were traced to locate at the same site of the human hair follicles. Under electron microscopy, juvenile cells, mature keratinocytes and apoptotic cells were found in the proliferating colonies. Conclusions The human hair follicles may contain two distinct reservoirs for stem cells, which locate in the bulge area and in the region of the outer root sheath above the hair bulb, respectively. Mesenchymes are needed for the proliferation of stem cells. New stem cells, mature keratinocytes and apoptotic cells may be three endings of the stem cells′ proliferation.
9.The absorption and metabolism differences of intestine and liver for multicomponent licorice water extract
Lei ZHANG ; Yanli PAN ; Yang LIU ; Mingmin TANG ; Li WEI ; Chengbo HOU ; Xiao CHENG ; Hao WANG
International Journal of Traditional Chinese Medicine 2015;(7):636-640
Objective This paper was to study the absorption and metabolism differences of intestine and liver for multicomponent licorice.Methods The components were identified with the UPLC-MS/MS. In situ closed-loop method was used to carry out the comparative experiments of absorption and metabolism differences between intestine and liver.Results 13 components were identified by UPLC-MS/MS. The absorption and metabolism results indicated some components in licorice water extract could be absorbed into blood and metabolism happened during this process. 14 metabolites were detected in the plasma sample. The hepatic metabolism results indicated many components could experience complex metabolism and more metabolites could be generated.Conclusions Liver was the major metabolism organ for licorice water extract and some components could be metabolized along with the absorption process in intestine. The absorption and metabolism differences between intestine and liver were significant.
10.Clinical significance of MRD detection in ALL-B of children by FCM
Guoping HAO ; Xiaohuan WANG ; Lei ZHU ; Hong CHANG ; Hongyu SHI ; Yanli CHENG
Journal of Leukemia & Lymphoma 2012;21(7):427-429
Objective To evaluate the clinical significance of minimal residual disease (MRD)detecion in ALL-B of children by flow cytometric (FCM).Methods 52 cases of children with ALL-B were performed bone marrow MRD by FCM analisis after induction therapy,3 moths therapy,and 6 moths therapy.After that,MRD detection was performed every 6 months. According to disease risks, three group were categorized,standard risk (SR),imidiete risk (IR) and high risk(HR).Results After 6 months,SR groups MRD positive cases were 4/21(19 %),IR groups MRD position cases were 8/23 (35 %),HR groups MRD position cases were 5/8 (63 %).9 cases relapsed in all 52 patients.There were significant differrence in replased rate between the positive and negtive MRD (P<0.001). Conclution The dynamic detection of MRD by FCM can be used to evaluate the therapeutic effect and prognosis of children with ALL-B. It is also useful in adjusting treatment strategy and for following up in children with ALL.