With the strengthening of nuclear weapon development and the expanding of neutron application in economic area,the injury accidents of neutron radiation are happening from time to time.Neutron exposure,with high linear energy transfer,has high casualty rate,severe symptom and poor prognosis.In comparison with low-LET radiation damage,neutron irradiation induced injuries are more difficult to rescue.This review focused on the recent research progresses of radiation effects,intrinsic mechanisms and clinical prevention measures of neutron radiation,and to provide a theoretical clue for establishing an effective prevention protocol of neutron radiation damage.

Intravoxel incoherent motion (IVIM) can distinguish the molecular diffusion from the pseudo-diffusion of microcircular perfusion to obtain true diffusion coefficient (D),pseudo-diffusion coefficient (D*) and perfusion fraction (f),which are sensitive to detect alterations in cellularity and microcirculation perfusion.IVIM can also evaluate early therapeutic effects,optimize treatment plan,predict prognoses,and provide information for choosing appropriate treatment methods.In this paper,the principle of IVIM and its application in tumor response evaluation were reviewed.

Objective To study the state and trends of Kesan disease in Henan province from 2004 to 2009. Methods Surveillance sites were selected: Guxian village of Luoning country from 2004 - 2007, Zuyang town of Lingbao city in 2008, and Shahe village of Lushi country in 2009. All residents of surveillance sites were examined by clinical and electrocardiogram, and suspected patients were inspected by chest X-ray to measure ardiothoracic ratio. Hair and wheat flour samples were collected and selenium levels were detected with hydride generation atomic fluorescence spectrometry. Results From 2004 to 2009, a total of 4034 people were examined.The numbers of chronic and latent KSD patients were 21 and 75 cases,respectively, and the incidence rates were 0.52%(21/4034) and 1.86%(75/4034), respectively . The number of abnormal electrocardiogram was 751 cases, and the incidence rate was 18.62%. The highest proportion of abnormal electrocardiogram was ST-T changes,accounting for 24.63%(185/751), followed by high-voltage, accounting for 18.11%(136/751), and left ventricular accounting for 13.85% (104/751). Sixty-one grain samples were collected and the wheat flour selenium level was averaged 0.034 mg/kg. Thirty hair samples were collected and the selenium median was 0.285 mg/kg. Conclusions The state of Keshan disease is in a steady state in Henna province, but higher rates of abnormal electrocardiogram is a serious problem and should be studied and prevented.

Objective To understand Kaschin-Beck disease(KBD) status in Henan Province and provide the basis for the further prevention and treatment of KBD. Methods Children aged 7 to 12 in 3 villages(Yaodian, Miaowa and Zhuyang) with the same environment such as topography, physiognomy,production mode and living habits in Shan County and Lingbao City were selected to undertake KBD clinical examination in 2008, X-ray examination of right hand and child hair samples and food samples were collected to determine the content of selenium. Selenium was determined using 2,3-Diaminonaphthalene method. Adults who were 16 years or older in 5 counties(Luoning, Lingbao, Mianchi, Shah and Lushi) were selected and examined for KBD. Results One hundred and ninty children aged 7 to 12 were clinically examined and clinical KBD were found, whereas 3 children were diagnosed as KBD by X-ray examination, the positive rate was 1.58% (3/190). All 20 521 adults were clinically examined and KBD prevelance rate was 6.10%(1251/20 521), including degree Ⅰ (3.97%,814/20 521), degree Ⅱ (1.77%, 364/20 521 ), degree Ⅲ (0.36%, 73/20 521). The average selenium contents in hair and food samples were (0.319±0.128)mg/kg and (0.031±0.009)mg/kg, respectively. Conclusions Child KBD in Henan Province is under control or almost under control, whereas the prevalence of adult KBD was relatively serious, which suggested that secondary prevention with the objective of clinically treating KBD patients should be strengthened.

BACKGROUND: Pathogenesis and pathophysiological changes of chronic compressive cervical myelopathy havenotbeen completely clarified.OBJECTIVE: To establish an animal model of experimental chronic compressive cervical myelopathy for the exploration of the pathological and electrophysiological changes after chronic spinal compression.DESIGN: A randomized and controlled observatory study using experimental animals as subjects.SETTING: An Animal Experimental Center of a University and an Orthopaedic Laboratory of Affiliated Hospital of a Military Medical University MATERIALS: The study was conducted in the Animal Experimental Center of Nantong Medical University and the Orthopaedic Laboratory of Shanghai Changzheng Hospital from June 2002 to April 2003. Sixty 12-week healthy Chinese rabbits of either gender with a bodymass between 2.5 kg and 3.0 kg were randomly divided into control group( n = 6) and study group( n = 54).METHODS: Titanic metal screw was put into C5 vertebra through cervical anterior approach for progressive compression to establish chronic cervical myelopathy model.MAIN OUTCOME MEASURES:Principal consequences: ①histological examination ;②electrophysiological examination. Secondary consequence:neural function evaluation.RESULTS: Totally 48 rabbits entered into result analysis, in which 6 rabbits from control group and 42 rabbits from study group. Modified Tarlov's motor function evaluation was 3 in 31 rabbits with compression signs, and 4 in 11rabbits without compression signs. The latency of N1 wave in cortical somatosensory evoked potentials (CSEP) was (9.11 ± 1.61 ), ( 11.36 ± 2.17)and (17.55 ± 3.73) ms respectively in animals of control group, animals of study group without compression signs and animals of study group with compression signs. The lantency of CSEP N1 wave was significantly longer in animals of study group with compression signs than that of the animals in the control group and study group without compression signs (P＜0.05).CONCLUSION: This animal model can simulate clinical invasion process of chronic compressive cervical myelopathy. The severer the spinal compression is, the more often the compression signs appear, the longer the lantency of CSEP N1 wave is, and the more serious the spinal pathological damages are.

Objective To explore the preparation of liposomal clodronate and investigate its inducing effects on the apoptosis of peritoneal macrophages in rats after severe acute pancreatitis (SAP).Methods Liposomal clodronate was prepared by means of thin film. SAP rat model was established by retrograde injection of 5% sodium taurocholate into the pancreatic duct. The peritoneal macrophages were obtained from SAP rats. After exposure to different doses of liposomal clodronate (50, 100,150 μl), the PM proliferation was determined by MTT colourimetry. The apoptosis of PM was measured by flow cytometry and agarose gel electrophoresis, respectively. Results The prepared liposomal clodronate had a suitable encapsulation efficiency of clodronate (5.8%) with an average size of 200 nm. The spherical shape of liposome was confirmed by transmission electron microscope. Exposed to liposomal clodronate of different doses resulted in a obvious growth depression (P＜0.01). The apoptotic rate of the PM was (10.32±0.34) %, (18.16±0.49)% and (29.87±0.35)% in three different dose groups and the difference was marked (P＜0.01). 1.2% of agarose gel electrophoresis of DNA extracted from apoptotic macrophages induced by liposomal clodronate showed clearer and characteristic ladder following the liposomal clodronate concentration. Conclusion Liposomal clodronate has a definite effect on peritoneal macrophages in SAP rats.

Objective To investigate the effect of pregnancy on the potency of bupivacaine for spinal anesthesia in rats. Methods Female non-pregnant SD rats weighing 180-220 g and 17 day pregnant SD rats weighing 350-400 g were used in this study. The rats ( 18 non-pregnant, 18 pregnant) in which PE-10 catheter were successfully placed without complications were selected. The 18 non-pregnant rats were randomly divided into 3 groups (n =6 each): control group (group C), 2% bupivacaine group (group B2 ) and 4% bupivacaine group (group B4). The 18 pregnant rats were also randomly divided into 3 groups (n = 6 each): control group (group PC),2% bupivacaine group (group PB2 ) and 4% bupivacaine group (group PB4 ). Group C and PC received intrathecal (IT) normal saline 30 μl, and the other 4 groups received 2% or 4% bupivacaine 30 μl intrathecally. Analgesia was determined using the taifllick latency (TFL) before IT administration (baseline), and at 10 min, 20 min,30 min, 1 h, 2 h, 4 h, 1 d, 2 d, 3 d and 4 d after IT administtation. The percentage of the maximal possible effect (MPE) was calculated. Hind-limb motor function (MF) was also assessed. Results Compared with the baseline value, MPE at 10 min-2 h after administration and MF scores at 10 min-1 h after administration were significantly increased in group B2, MPE at 10 min-4 h after administration and MF scores at 10 min-1 h after administration were significantly increased in group B4;MPE at 10 min-1 d after administration and MF scores at 10 min2 h were significantly increased in group PB2 and MPE at 10 min-1 d after administration and MF scores at 10 min4 h were significantly increased in group PB4 ( P ＜ 0.05 ). Conclusion Pregnancy can enhance the potency of bupivacaine for spinal anesthesia in rats.

OBJECTIVE:To study the preventive and therapeutic effect and its mechanism of medicine pair decoction liquid of Curcuma phaeocaulis-Sparganium stoloniferum on rats with uterine myoma. METHODS:Rats were randomly divided into normal group,model group,positive group(mifepristone,2.25 mg/kg)and medicine pair decoction liquid group(C. phaeocaulis-S. stolon-iferum decoction liquid,6.0 g/kg),10 in each group. Except for the normal group,rats in other groups were injected Estradiol ben-zoate injection (0.5 mg/kg) intramuscularly every Monday,Wednesday and Friday,for 12 weeks. From the 13th week,rats in modeling group were added Progesterone injection(5 mg/kg)intramuscularly as well as relevant medicines intragastrically,once a day,until the 16th week. After administration,uterine coefficient of rats was detected. HE staining was used to observe the patho-logical changes of uterus and determine the thickness of smooth muscle;immunohistochemical staining was adopted to detect the transforming growth factor β3 (TGF-β3),matrix metalloproteinase 11 (MMP-11) protein expressions in uterus tissue of rats. RE-SULTS:Compared with normal group,uterine coefficient was increased in model group,pathological changes were obvious in uterus,thickness of smooth muscle was increased,TGF-β3 and MMP-11 protein expressions were enhanced(P<0.05 or P<0.01). Compared with model group,above-mentioned changes were improved significantly in positive group and medicine pair decoction liquid groups(P<0.05 or P<0.01). CONCLUSIONS:Medicine pair decoction liquid of C. phaeocaulis-S. stoloniferum shows cer-tain preventive and therapeutic effect on rats with uterine myoma. The mechanism may be associated with downregulating the TGF-β3,MMP-11 protein expressions in uterus tissue.

Objective To observe the change of conditions and study the epidemiology of Keshan disease from 1995 to 2009 in Henan province.Methods From 1995 to 2009,seriously ill township (village) of Keshan disease were selected as monitoring sites,and one cross-sectional survey was conducted annually.Resident population were asked of their disease history,and were taken clinical examination.Suspicious or suspected cases of Keshan disease and people with abnormal ECG were taken 2 m X-ray.Hair and wheat flour samples were collected for selenium testing.Results From 1995 to 2009,about 6632 people were checked,130 chronic and 52 latent cases of Keshan disease were identified,the total detection rates were between 1.12％ and 5.06％.The detectable rate for abnormal electrocardiogram and heart enlargement found through chest X-ray examination were 10.24％ -30.65％ and 32.4％ - 77.8％,respectively.The content of hair selenium tended to increase,the highest was in 2009 (357.12 μg/kg),and the lowest was in 1997( 142.68 μg/kg).Conclusion Keshan disease is stable in Henan province,and prevention and control measures should be strengthen gradually.

OBJECTIVE:To study the decoction rate changes of 4 active ingredients in the volatile oil of Curcuma phaeocaulis before and after combined with Sparganium stoloniferum,and provide reference for showing the compatibility mechanism of C. pha-eocaulis and S. stoloniferum. METHODS:HPLC was used to simultaneously determine the contents of 4 active ingredients(curdi-one,curcumol,germacrone and β-elemene) in the volatile oil of C. phaeocaulis after C. phaeocaulis single decoction and com-bined decoction with S. stoloniferum. And the fried rates of each ingredient were compared. RESULTS:Compared with C. phaeo-caulis single decoction,there was significant difference in the fried amounts of curdione,curcumol,germacrone in the volatile oil after combined decoction(P<0.05)and no significant difference in fried rate ofβ-elemene(P>0.05). CONCLUSIONS:The com-bined decoction of C. phaeocaulis and S. stoloniferum can effectively improve the dissolution of curdione,curcumol,germacrone in the volatile oil. It may be the reason for the enhancement of efficacy after compatibility.