BACKGROUND:Al oying is a convenient and effective method to alter the microstructure and control the corrosion behavior of magnesium al oy.
OBJECTIVE:To explore the in vitro and in vivo degradation of Mg-Nd-Zn-Zr al oy as a degradable medical biomaterial.
METHODS:(1) In vitro static immersion test:The immersion tests were carried out at (37.0±0.5) thermostatic bath. Six Mg-Nd-Zn-Zr al oy samples and six pure magnesium samples were immersed in the 250 mL simulated body fluid and vibrated without agitation during immersion. After 3, 7 and 30 days static immersion, the samples were taken out from the simulated body fluid. Then the in vitro corrosion properties were evaluated using scanning electron microscope and energy dispersive spectrometer analysis. (2) In vivo animal experiment:After bone tunnel was established in the left femur of adult New Zealand rabbits, the Mg-Nd-Zn-Zr al oy rods were embedded in the Mg-Nd-Zn-Zr al oy group, titanium al oy rods were embedded in the titanium al oy group, and only bone tunnel was established in the sham-operated group. At 1, 2, 4, 8 weeks after implantation, an X-ray of the implanted region was taken to determine the location and the degradation behavior℃in a of Mg-Nd-Zn-Zr al oy. At 4, 8 weeks after implantation, the corrosion product and its element composition were observed using scanning electron microscope with an energy dispersive spectroscopy system.

Total elbow arthroplasty was initially used to manage the rheumatoid arthritis of elbow. With the developement of technology in recent decades, the indication of total elbow arthroplasty include the trauma associated unstable joint, traumatic arthritis and distal humerus fractures in elderly. But the high risk of complications, which includes infection, ulnar nerve deficit and tricep insufficiency, is still an unsolved issue. The most widely used approach nowadays is the Bryan-Morrey approach, while some authors also report triceps on approach recently. This article is an overview in approaches and biomechanical researches of total elbow arthroplasy by reviewing the domestic and overseas involved literatures.
Arthroplasty, Replacement, Elbow ; adverse effects ; methods ; Humans ; Muscles ; physiopathology ; Recovery of Function ; Ulnar Nerve ; injuries

Objective To understand willingness of current medical undergraduates to work at community health-care service(CHS)institutions after their graduation to provides information for professional training for them.Methods Totally,2714 medical undergraduate students were recruited from three medical schools in east,middle and west China by multi-level sampling methods for questionnaire survey on their basic information and willingness to be employed at CHS institutions.results of the survey were described by relative numeric and tested by chi-square test for smtistical inference.Results About 60.6%of medical undergraduate students were willing to work at CHS organizations permanently or temporarily.Their willingness to work there differed with their native living areas and grades they were studying significantly(P＜0.01).Reason for those they would work at CHS organizations after graduation included work less stress and easier,and that for those reluctant to work there included low-income and lack of social respect for general practitioners.Conclusions Nowadays,few medical undergraduate students would like to work at CHS organizations after their graduation,which was influenced mainly by traditional ideas and concepts of employment,personal career devdopment,economic income,and so on.It is suggested that ideas of community work be strengthened for medical undergraduate students and their employment concepts be changed in the future.

Objective To investigate the significance of sonographic patterns of thyroid calcification in diagnosis of thyroid nodule.Methods 235 patients with 355 thyroid nodules were retrospectively analyzed.Nodule calcification size,distribution and pattern were observed.Results The incidence of calcification in benign and malignant nodules was 30.3％ (89/294)and 73.7％ (45/61) respectively.The difference had statistical significance(x2 =24.3,P ＜0.01).The rate of microcalcification in cancer was 47.5％ (29/61),higher than that in benign one 3.1％ (9/294)(x2 =99.1,P ＜ 0.01).Coarse calcification in benign nodules and malignant lesion was 27.2％ (80/294)and 26.2％ (16/61)respectively.The difference had no statistical significance(x2 =0.42,P ＞0.05).Conclusions Microcalcification of thyroid nodules is a specific index for thyroid carcinoma.Any type of sonographically detected calcification represents risk of malignancy.Not only microcalcification,these cases should raise the suspicion of malignancy in coarse calcification,especially involving a solitary nodule and irregular shape.

Objective To understand the type and frequency of the gene mutation in exon 6 of phenylalanine hydroxylase(PAH) in the children of Ningxia,in order to provide foundation for phenylketonuria(PKU) gene diagnosis and prenatal diagnosis.Methods The exon 6 and flanking introns of 73 cases of classic PKU patients in Ningxia[all confirmed at Ningxia Neonatal Screening Center from Jan.2010 to Jun.2013,and distributed in Ningxia 22 County (city,district),aged from 15 days to 13 years,including 38 male cases,35 female cases,and Hui 39 cases,Han 34 cases] as well as 100 healthy newborn babies(Hui 50 cases;Han 50 cases) were sequentially analyzed by using the approach of PCR direct sequencing.Results There were 6 kinds of mutations detected,including EX6-96A ＞ G(6.85％),Q232X(2.74％),D222G(1.37％),V2301 (1.37％),R176X (0.68％) and N223I (0.68％).Mutation detection rate of exon 6 was 13.70％,and there were 3 mutation types:50.0％ missense mutation (3 types) ;33.3 ％ nonsense mutation (2 types) ;16.7％ cleavage site mutation(1 type).After reviewing the previous studies,the researchers had found out that EX6-96A ＞ G,Q232X and R176X were ever reported in China,and V2301 and D222G had been reported in our country for the first time but N223I was a new kind of PAH gene mutations were not been reported in the world.Conclusions It has defined the gene type and frequency of PAH gene mutations in exon 6 in the children of Ningxia and it will enrich the research of PKU in this area,and provide the basis for the development of gene diagnosis of PKU.

OBJECTIVETo study the relationship between serum load level of HBV-DNA and therapeutic effect of oxymatrine in patients with chronic hepatitis B.

METHODSForty-four patients of chronic hepatitis B were divided into two groups, the treated group was treated with oxymatrine 0.4 g/d by intramuscular injection for 3 months, the control group was treated with some liver protecting agents to estimate the therapeutic effect. The serum level of HBV-DNA was determined by quantitative polymerase chain reaction (PCR) before and after treatment.

RESULTSThe seroconversion rate of HBV-DNA and HBeAg in the treated group was 43.47% and 43.47% respectively, which was obviously better than those in the control group respectively (P < 0.05), the quantity of HBV-DNA decreased after treatment from 10(6.83 +/- 1.27) copy/ml to 10(3.35 +/- 3.08) copy/ml. Among them, in patient with HBeAg negative conversion, the pretreatment quantity of HBV-DNA was 10(6.30 +/- 1.42) copy/ml, while in those with no HBeAg negative conversion, it was 10(7.23 +/- 1.23) copy/ml, the difference was significant.

CONCLUSIONOxymatrine is effective in treating chronic hepatitis B. The therapeutic effect is better for patients with lower quantity of serum HBV-DNA.

Adult ; Alkaloids ; therapeutic use ; Antiviral Agents ; therapeutic use ; DNA, Viral ; blood ; Female ; Hepatitis B e Antigens ; blood ; Hepatitis B virus ; genetics ; isolation & purification ; Hepatitis B, Chronic ; drug therapy ; virology ; Humans ; Injections, Intramuscular ; Male ; Middle Aged ; Polymerase Chain Reaction ; Quinolizines

Objective To characterize the mutation of phenylalanine hydroxylase (PAH) gene in patients with phenylketonuria(PKU) in Ningxia area,China.Methods Seventy-three children diagnosed with PKU at the Child and Maternal Healthcare Hospital of Ningxia Hui Autonomous Region between January 2010 and June 2013,and 100 non-PKU children randomly chosen from children with normal results in PKU screening were enrolled in the study.Venous blood was collected and the PAH gene sequence was determined by direct DNA sequencing after amplification with the polymerase chain reaction technique.The new gene mutations were defined based on the national and international literature search and databases.The source of the newly discovered mutations was also measured by examining and sequencing the blood samples of their parents.The Chi-square test was used for statistical analysis.Results Among 146 alleles of the 73 PKU children,the detection rate of mutation of PAH gene was 79.5％ (116/146),including 37 types of mutations occurring in 11 exons other than exon 2 and exon 13.The 37 different mutations included 22 missense mutations (59.5％,22/37),six nonsense mutations(16.2％,6/37),six splice site mutations(16.2％,6/37) and three deletion mutations(8.1％,3/37).p.R243Q(17.1％,25/146),EX6-96A ＞ G (6.8％,10/146),p.R241C(6.2％,9/146),p.R413P (5.5％,8/146),p.Rl11X(4.8％,7/146) and IVS4-1G ＞ A(4.8％,7/146) were found to have a higher mutation frequency.Meanwhile,p.R243Q was the most common mutation among Han and Hui ethnic groups with a frequency of 18.8％(12/64) and 15.9％ (13/82),respectively.In contrast,p.R241C showed a significant higher frequency in the Hui group [9.8％(8/82) vs 1.6％(1/64),x2=4.17,P=0.04].Four new mutations of PAH genes,including p.Q304K,p.H107R,p.F392I and p.N223I,were discovered after literature search and comparative studies.Conclusions PAH gene mutations in children with PKU in Ningxia area are unique and are characterized by the diversity and complexity of mutation occurrence in this ethnic region.

ObjectiveTo approach the taxonomy of polymer hydrogels prepared with composite material science methods.MethodsThe research results which have been obtained were synthesized and analysed in the light of multiscale design viewpoint,and the hydrogel composite materials were classified by the composite ways and its structural levels.Results and ConclusionA kind of taxonomy system was advanced in which new concepts of intermolecular composite,textural composite etc.were induced.Apply-ing these concepts and methods will be helpful to research on composite biomaterials.

OBJECTIVETo evaluate clinical efficacy of suture anchors in treating acute injuries of medial collateral ligament (MCL) of knee at degree III.

METHODSTwenty-seven patients with degree III acute MCL injuries of knee were treated with suture anchors from January 2007 to June 2011. There were 15 males and 12 females, aged from 19 to 56 (averaged 32.6) years old. The time from injury to operation was 3 to 10 days, averaged 6 days. Symptoms and physical signs before and after treatment were observed, Lysholm scoring were used to evluated clinical efficacy.

RESULTSAll patients were followed up from 16 to 30 months with an average of 21.6 months. The stability of knee joints was good in all patients. Abduction stress test was negative when the knee joint was straightened at 0 degrees and flexed at 30 degrees. The average degree of flexed knee (67.00 +/- 5.80) degrees preoperatively was lower than that of postoperatively (136.50 +/- 6.30) degrees at 1 year. According to Lysholm scoring, preoperative scores ranged from 30 to 43 points, averaged 36.46 +/- 1.48; 1 year after operation ranged from 87 to 100 with an average of 91.50 +/- 3.80 and higher than postoperative. Twenty patients got an excellent results, 5 good and 2 fair.

CONCLUSIONSuture anchors in treating acute injuries of medial collateral ligament of knee at degree III has following advantages: small range of tissue dissection, easy to operate, reliable fixation and less complications.

Acute Disease ; Adult ; Collateral Ligaments ; injuries ; surgery ; Female ; Humans ; Knee Injuries ; surgery ; Male ; Middle Aged ; Suture Anchors

Fractures of distal humerus in elderly patients are difficult to treat, as diminished bone mineral quality and increased trauma-associated articular surfaces destruction may make stable joint reconstruction even more difficult. In active patients, internal fixation is still a primary choice because of use age of total elbow replacement, but disagreements have still existed on how to treat these fractures in elderly patients. In the past years, treatment of fractures of distal humerus make much progress, including the introduction of dual plates fixation, widespread application of three-dimensional CT reconstruction, recognition of complicated fractures, understanding of the parallel plate technique, application of periarticular plates, and the selective use of total elbow arthroplasty. This article is an overview in treating options of fracture of distal humerus in the elderly patients by review the civil and overseas involved literatures.
Aged ; Aged, 80 and over ; Elbow Joint ; surgery ; Female ; Fracture Fixation, Internal ; Humans ; Humeral Fractures ; surgery ; Male