Environmental Microbiology is an important basic course of Environmental Engineering.Its characteristic is content broad,quick development and strong practicality,thus this curriculum's teaching has certain degree of difficulty.Some suggestions and concrete measures about teaching reform,which included curriculum's course content,teaching method,experiment teaching and assessment methods were proposed in this paper.

Objective To investigate the possible mechanism of endonuclease G (Endo G)-mediated non-Caspase-dependent apoptotic pathway in brain neuronal apoptosis in chronic fluorosis rats.Methods Sixty Sprague Dawley (SD) rats (half male and half female) were randomly divided into two groups:control group fed with tap water with fluoride content ＜ 0.5 mg/L and fluorine group in which sodium fluoride was added into drinking water with fluoride content of 50.0 mg/L.Both groups were fed with standard food with fluorine content ＜ 0.5 mg/kg.The experiment period was 10 months.At the end of the experiment,all the animals were sacrificed,and brain tissue was taken.Flow cytometry was used to examine apoptosis rate,immune-histochemistry was employed to detect the distribution of Endo G in brain tissue;Western blotting was used to test the protein expression of Endo G.Results Compared to the apoptosis rate of control group [(1.3 ± 0.6)％,(1.9 ± 0.3)％],the apoptosis rate in hippocampus and cortex of rats with chronic fluorosis [(2.6 ± 0.6)％,(3.1-± 0.7)％] was significantly increased (t =3.1,3.4,all P ＜ 0.05).The Endo G positive neurons and their degree of staining in CA1,CA2,CA3 and CA4 of hippocampus,frontal cortex as well as the upper layer of parietal cortex [(11.1 ± 2.2),(10.2 ± 1.9),(9.8 ± 3.1),(9.9 ± 1.6),(10.6 ± 2.9),(8.2 ± 2.4),(11.1 ± 2.8) scores] in rats with chronic fluorosis were significantly higher than those in the control group [(5.8 ± 1.8),(6.7 ± 2.6),(5.2 ± 2.4),(7.2 ± 2.1),(7.7 ± 2.6),(6.1 ± 1.9),(8.1 ± 2.6) scores,t =2.9,2.5,2.4,2.3,2.2,2.5,2.3,P ＜ 0.01 or ＜ 0.05].The protein level of Endo G in the mitochondria of rat brains with chronic fluorosis [(86.4 ± 7.2)％,(83.9 ± 6.8)％] was significantly lower than that of control group [(100.0 ± 6.1)％,(100.0 ± 5.5)％,t =2.6,2.3,all P ＜ 0.05].Meanwhile,the protein level of Endo G in the nucleus of neurons from chronic fluorosis rats [(117.5 ± 6.4)％,(115.2 ± 6.2)％] was significantly higher than that of the control [(100.0 ± 5.2)％,(100.0 ± 5.5)％,t =2.5,2.2,all P ＜ 0.05].Conclusion The high expression of Endo G and nuclear transfer are related to the neuron apoptosis in chronic fluorosis rat,which may be one of the mechanisms of brain injury of the disease.

Objective To determine the Golgi dispersal in radiation damaged cells and the protective effect of vanillin derivatives.Methods Immunofluorescence, cell cycle analysis of flow-cytometry,Western blot,and clone formation were used.Results Immunofluorescence observation showed that the Golgi dispersal caused by 2 Gy 60 Coγ-ray was significantly increased in a dose-dependent manner in the range of 4-10 Gy as was demonstrated by the fact that the Golgi area was significantly increased. When the irradiated cells were treated with the radioprotective agent VND3207, a vanillin derivative,the Golgi dispersal induced by radiation was significantly reduced.The radiation-induced Golgi dispersal was also displayed in a pattern of time-course after irradiation in the HeLa cells, and persisted at least to 36 h post-irradiation. Cell cycle test results indicated that the Golgi dispersal was not associated with the G2/M arrest triggered by radiation-induced DNA damage response.VND3207 could promote cell survival by plate colony formation assay.Conclusion The Golgi dispersal can be caused byγ-ray irradiation in a dose-and time-dependent manner, and VND3207 can provide a good protection against radiation injury associated with inhibited Golgi dispersal.

Objective To observe the pronunciation characteristics of vowels' tone in prelingual hearing-impaired children accepted cochlear implant (CI). Methods 8 prelingual hearing-impaired children accepted CI aged 3~4 years (group CI) and 8 normal-hearing children (group NH) with the same age were asked to pronounce the vowels of /a/, /o/, /e/, /i/, /u/, and /ü/ in four tones with the direction of speech training teacher. The sounds were recorded and analyzed with Praat software extract Formants (F1, F2) and duration of the sounds. Results The error of vowels in four tones was more in group CI than in group NH, but difficult level was almost the same between groups. There was significant difference in the F1 of /e/, F2 of /i/ and /u/ in tone 2, F2 of /e/ and duration of /o/, /e/, and /ü/ in tone 3 between groups (P<0.05). Conclusion Pronouncing the four tones of vowels is more difficult for the hearing-impaired children. For vowels articulation training,it is important to focus on the mouth and breath training.

Objective: To investigate the occupational health status of medical radiation workers in Hangzhou City, so as to provide the basis for their occupational health risk assessment. Methods: Data on medical radiological workers who underwent occupational health examinations from 2021 to 2022 were collected through the Physical Examination Information Management System of the Hangzhou Occupational Disease Prevention and Control Hospital. The physical examination data including blood routine, eye lens, thyroid ultrasound, thyroid function, liver function, renal function and blood lipid were collected, and the abnormal rates of occupational health examinations among workers with different genders, working years and occupational exposure types were analyzed. Results: A total of 3 968 medical radiation workers were investigated, including 2 310 males (58.22%) and 1 658 females (41.78%). There were 2 039 (51.39%), 821 (20.69%) and 1 108 (27.92%) workers with 1-<6, 6-<10 years and 10 years and above of work, respectively. Diagnostic radiology was the predomenant type of exposure, with 2 240 workers accounting for 56.45%. The abnormal rates of thyroid ultrasound and blood lipid were 47.73% and 45.21%, respectively, which were relatively higher than other items. The abnormal rates of micronucleus rate, thyroid ultrasound, thyroid function and renal function were higher in females than in males, while the abnormal rates of lymphocyte count, liver function and blood lipid in males were higher in males than in females (all P<0.05). With the increase of working years, the abnormal rates of micronucleus rate and blood lipid showed upward trends (both P<0.05). There were statistically significant differences in the abnormal rates of thyroid ultrasound, liver function and blood lipid among different occupational exposure types (all P<0.05). Conclusion Long-term low-dose ionizing radiation environment affects the thyroid, micronucleus rate and blood lipid of medical radiation workers in Hangzhou City, with differences observed among workers with different genders and occupational exposure types.

Objective To investigate the effects of TLR7 on imiquimod induced apoptosis of THP-1 derived macrophages.Methods Three cell lines ( THP-1 derived macrophages, MDCK cell line and HUVEC cell line) with different capabilities of expressing TLR7 were selected.The survival rates of cells af-ter the treatment with different concentrations of imiquimod were detected by MTT assay.The levels of IL-6 in the supernatants of TLR7 inhibitor chloroquine or TLR7-siRNA treated cells were detected by enzyme-linked immunosorbent assay.The apoptosis of cells was detected by flow cytometry after inhibiting the ex-pression of TLR7.Results Imiquimod induced the apoptosis of THP-1 derived macrophages, MDCK cell lines and HUVEC cell lines.The levels of IL-6 were significantly decreased as the expression of TLR7 was inhibited by treating THP-1 derived macrophages with chloroquine or TLR7-siRNA.Treating THP-1 derived macrophages with chloroquine or TLR7-siRNA did not affect the cell apoptosis induced by imiquimod.Con-clusion Imiquimod could induce the apoptosis of THP-1 derived macrophages through TLR7 independent pathway.

Objective To evaluate the value of transvaginal ultrasound in diagnosing intrauterine adhesions.Methods Transvaginal ultrasound was performed in 136 patients with suspicious intrauterine adhesions and compared with hysteroscopy correspondingly .The ultrasonographic features of intrauterine adhesions on transvaginal ultrasound were summarized .Results One hundred and twenty one cases (89.0%, 121/136 ) of intrauterine adhesions were verified by hysteroscopy .The hysteroscopic findings included:(1) Forty seven cases(38.9%,47/121) were minimal intrauterine adhesions , 46 cases(38.0%, 46/121) were moderate intrauterine adhesions , and 28 cases (23.1%,28/121) were severe intrauterine adhesions.(2) Sixty one cases(50.4%,61/121) were central intrauterine adhesions , 24 cases(19.8%, 24/121) were marginal intrauterine adhesions , and 36 cases (29.8%, 36/121) were mixed type of intrauterine adhesions.The transvaginal ultrasound findings included:(1)Nineteen cases(40.4%,19/47) were minimal intrauterine adhesions ,33 cases(71.7%,33/46)were moderate intrauterine adhesions ,and 23 cases(82.1%,23/28) were severe intrauterine adhesions .(2) Thirty nine cases (63.9%,39/61) were central intrauterine adhesions ,9 cases(37.5%,9/24) were marginal intrauterine adhesions ,and 27 cases (75.0%, 27/36 ) were mixed type of intrauterine adhesions .By transvaginal ultrasound, seventy-five (62.0%,75/121) cases of intrauterine adhesions were correctly diagnosed , whereas 46 cases (38.0%, 46/121) were missed.And 3 cases ( 3.8%, 3/78 ) were misdiagnosed as intrauterine adhesions on transvaginal ultrasound,including one endometrial polyp ,one thin endometrium and one septate uterus .The sensitivity, specificity and accuracy of transvaginal ultrasound in diagnosing intrauterine adhesions were 62.0%(75/121), 80.0%(12/15) and 64.0%(87/136) respectively.There were significant statistical differences in diagnosing different degrees of intrauterine adhesions ( χ2 =15.956,P=0.000) and different parts of intrauterine adhesions( χ2 =8.792,P=0.012) by transvaginal ultrasound.Conclusions Transvaginal ultrasound is an effective, easy to perform and noninvasive technique in screening and diagnosing intrauterine adhesions.Transvaginal ultrasound is an effective way in diagnosing intrauterine adhesions showing a noninvasive and simpler way than hysteroscopy .Transvaginal ultrasound is of great value in screening and diagnosing intrauterine adhesions .

In most mammalian central nervous system diseases, axons are damaged.Due to the limited ability of damaged neurons to promote axonal regeneration, the formation of glial scar and the release of inhibitory nutrients, it is difficult to regenerate axons of damaged neurons. The purpose of this study was to investigate the effect of cerebroprotein hydrolysate for injection (II) (CBL) on neuritogenesis and its underlying mechanism. Immunofluorescence staining was used to detect the axon length of mouse neuroma cells (Neuro-2a) and mouse primary cortical neuronal cells. Western blotting was used to detect the expression of phosphorylated TrkB protein in Neuro-2a cells and mouse primary cortical neuronal cells. The results showed that CBL could increase the axon length of Neuro-2a cells or mouse primary cortical neuronal cells, and that the phosphorylation level of TrkB in neuronal cells was significantly increased when 5 μg/mL CBL was applied to neuronal cells for 1 h. In conclusion, CBL can promote neuritogenesis, and increase the expression of phosphorylated TrkB, which may be related to the activation of TrkB signaling pathway.

Background Trachoma is a common disease in ophthalmology,but few reports about the pathogenetic genotype are reported.Objective This study was to investigate the genotypes of Chlamydia trachomatis.Methods Conjunctival specimens were collected in 16 patients with trachoma in Beijing Tongren Eye Center from January,2003 and August,2006.Variable sequence 4 (VS4) of ompl fragment was amplified by nested PCR(n-PCR) using specific primer of Chlamydia trachomatis,and then the PCR products were sequenced.The DNA sequences were analyzed by software Clustal X and MEGA2,and the genetic characteristics were compared with the known sequences of GenBank.Results The PCR product fragment of MOMP gene of trachoma was 277 bp.Three types of Chlamydia trachomatis strains were idcntified in the 16 specimens,including B-genotype in 9 strains (56.3％),C-genotype in 4 strains(25.0％) and D-genotype in 3 strains(18.7％).High homology was seen in the gene sequences of Chlamydia trachomatis strains between the B-genotype or C-genotype strains and the same genotypes of GenBank or those from some districts of China.However,some differences were exhibited among the Dgenotype strains.Conclusions Identification of genotype of Chlamydia trachomatis has differential effect on trachoma and inclusion conjunctivitis.

Objective To explore the role of apoptosis-inducing factors (AIF) mediated non-apoptosis classic pathway involved in neuron apoptosis of rats with chronic fluorosis.Methods Sixty Sprague Dawley (SD) rats (body weight 100-120 g) were divided into two groups (30 rats in each group,half male and half female) by random number table according to body weight.Control group was fed with tap water with fluoride content ＜ 0.5 mg/L and fluorine group was fed with water with fluoride content of 50.0 mg/L.Both groups were fed with standard food with fluorine content ＜ 0.5 mg/kg.After 10 months,all the animals were sacrificed though heart perfusion using phosphate buffer,and brain tissue was taken.Immunohistochemical method was employed to detect the distribution of AIF in brain tissue.Western blotting was used to test the protein expression of AIF,cl-caspase-3 and cl-caspase-9.Flow cytometry was used to examine apoptosis rate.Results The AIF positive distribution and degree of staining in the neurons of hippocampal CA1,CA2 and CA3,as well as the parietal cortex (7.50 ± 2.17,9.00 ± 1.63,8.00 ±0.82,10.24 ± 1.80) in rats with chronic fluorosis were significantly higher than those of the control group (5.18 ±1.66,6.27 ± 1.42,6.36 ± 1.96,6.96 ± 2.62,t =2.76,4.09,2.45,5.77,all P ＜ 0.05).The AIF protein expression of neuronal mitochondria in the cerebral tissue of rats with chronic fluorosis [(89.46 ± 8.47)％] was significantly lower than that of the control group [(100.00 ± 7.12)％,t =3.16,P ＜ 0.01],while the AIF protein expression of the neuronal nucleus [(112.80 ± 7.10)％] was significantly higher than that of the control group [(100.00 ± 8.20)％,t =3.75,P ＜ 0.01];cl-caspase-3 and cl-caspase-9 protein expression in the neurons of hippocampus and cortex from the rats with chronic fluorosis [(132.14 ± 18.66)％,(107.31 ± 2.58)％,(121.33 ± 14.86)％,(112.97 ± 7.97)％]were significantly higher than those of the control group [(100.00 ± 11.99)％,(100.00 ± 3.74)％,(100.00 ± 16.87)％,(100.00 ± 8.04)％,t =3.55,3.94,2.32,2.81,P ＜ 0.01 or ＜ 0.05].As compared with those of the control group [(1.28 ± 0.59)％,(1.88 ± 0.25)％],the apoptosis rates in hippocampus and cortex of the rats with chronic fluorosis [(2.55 ± 0.58)％,(3.05 ± 0.65)％] were significantly increased (t =3.08,3.40,all P ＜ 0.05).Conclusion Both of AIF-mediated caspase-independent apoptosis and the classic caspase-dependent apoptosis pathways have participated in neuron apoptosis in rat induced by chronic fluorosis,which may be one of the mechanisms of brain damage of the disease.