The biological storage equipment for liquid nitrogen has gone through three main development stages:biological container for liquid nitrogen,large-diameter container for liquid nitrogen,and tank for gas-phase liquid nitrogen,becoming a cross-product with multidisciplinary integrating cryobiology,vacuum and cryogenics technique,intelligent control technique and mechanical manufacturing.With the development of biological storage equipment for liquid nitrogen,a great deal of application achievements have been obtained in cryogenic insulation technology,vacuum technology,structure design,manufacturing process and experimental research in China.In view of the demand of the construction for large-scale biological sample bank in China,some key technologies and solutions in the development of the tank for gas-phase liquid nitrogen towards integration,intelligence and green were reviewed in this paper.At the same time,in order to make the tank for gas-phase liquid nitrogen,a new product,to suit for the development of industrial intelligence in China,we proposed suggestion to incorporate this kind of product into the standardized management as soon as possible.

Objective:To evaluate the mechanical stability of the bone block after LeFort Ⅰ osteotomy with maxillary advancement using absorbable plates fixed with tenon-and-mortise structures.Methods:This study developed three finite element models: one for the maxillary LeFort Ⅰ osteotomy with anterior advancement fixed with absorbable plates (Model 1); another for the maxillary LeFort Ⅰ osteotomy with anterior advancement fixed with absorbable plates assisted by tenon-and-mortise structures (Model 2); and the last one for the maxillary LeFort Ⅰ osteotomy with anterior advancement fixed with titanium plates and screws (Model 3). Simulated occlusal forces were applied on the anterior and posterior teeth in each model. The displacement changes of the nasal-palatine point (NP) and posterior nasal spine point (PNS) in the finite element coordinate system were compared and analyzed. The Mises equivalent stress distributions of the metal and absorbable plates were also examined to assess the mechanical stability of the three finite element models. Clinical data from 45 patients with dentofacial deformities treated from January 2017 to January 2023 at the Stomatology Hospital of China Medical University were collected. The age of the patients was 21±3 years. Among these, 15 patients had absorbable plates for fixation, 15 had absorbable plates assisted by tenon-and-mortise structures, and 15 had titanium plates and screws fixation after maxillary advancement. All patients underwent preoperative (T0), postoperative 3 days (T1), and 6 months (T2) spiral CT scans. The CT data in DICOM format were input into digital software, which was used to calculate the distances from the NP and PNS points to the horizontal plane (HP), right sagittal plane (FZSR), and coronal plane (CP) at T1 and T2. The distances at T1 and T2 were statistically analyzed using the Wilcoxon signed-rank test with SPSS 20.0, and a P value of<0.05 was considered statistically significant.Results:The finite element analysis showed that in the absorbable plate-only fixation group, the maximum displacement of the NP point (mm) under anterior and posterior tooth force conditions were 0.6 and 0.12, respectively, and for the PNS point, the maximum displacements were 0.5 and 0.11. In the tenon-and-mortise-assisted absorbable plate fixation group, the displacement of the NP point was 0.40 and 0.02 mm, and the displacement of the PNS point was 0.5 and 0.015 mm. In the titanium plate-screw fixation group, the NP point displacement was 0.33 and 0.055 mm, and the PNS point displacement was 0.16 and 0.1 mm. The Mises equivalent stress on the absorbable plates with tenon-and-mortise structure was significantly lower than that in the absorbable plate-only fixation group, while the titanium plate experienced the highest Mises equivalent stress. The clinical data analysis showed that in the horizontal direction, the postoperative stability of the three fixation methods was similar. However, in the vertical and anterior-posterior directions, the absorbable plate-only fixation group showed significant differences in the distances of PNS-HP, PNS-CP, and NP-CP between T1 and T2 ( P=0.018, P=0.009, P=0.017), suggesting significant postoperative bone displacement. In contrast, the tenon-and-mortise-assisted absorbable plate fixation group and the titanium plate-screw fixation group showed no significant differences in displacement during surgery and postoperatively(all P>0.05), demonstrating higher stability. Conclusions:The tenon-and-mortise-assisted absorbable plate fixation provides comparable stability to titanium plate fixation in clinical results, and it is more stable than absorbable plate-only fixation. In the mechanical study, when force was applied on the anterior teeth, the stability of the tenon-and-mortise-assisted absorbable plate fixation was slightly less than that of titanium plate fixation, but when posterior teeth were used, its stability exceeded both titanium plate fixation and absorbable plate-only fixation. The tenon-and-mortise-assisted absorbable plate fixation serves as an effective alternative to titanium plate fixation after LeFort Ⅰ osteotomy.

Reninoma is a rare renal secretory tumor，prevalent in the young population. This disease is mostly surgically resected，and the use of microwave ablation to treat reninoma in children is scarce. A case of reninoma in a child was reported in this paper. The patient presented with refractory hypertension，hypokalemia，hyperreninemia and hyperaldosteronemia. Enhanced CT and contrast-enhanced ultrasound showed mass in the lower pole of the right kidney，which was considered as reninoma and microwave ablation was performed. The renin concentration decreased to 68.42 pg/ml at 4 hours after surgery. After 1 year of postoperative follow-up，there was no recurrence of hypertension and hypokalemia，and no signs of tumor recurrence were seen on repeated ultrasound examinations.

OBJECTIVE: To utilize Spinal Cord Toolbox (SCT) to measure the morphological parameters of healthy cervical spinal cords and explore the impact of gender, age and vertebral levels on them. METHODS: A retrospective study was conducted, collecting cervical spinal cord magnetic resonance images of 184 healthy adults. Then, cross-sectional area (CSA), eccentricity, antero-posterior diameter (AP) and right-left diameter (RL) were each computed for every subject. Then, impacts of gender, age and vertebral level on CSA and eccentricity were explored. Moreover, linear correlation analysis was conducted among CSA, AP and RL. RESULTS: The CSA of the cervical spinal cord in males was significantly larger than that in females at C2~C7 segments (P＜0.05) . For C2~C6 segments, there was no statistically significant difference in CSA between the young and middle-aged groups, but both were significantly larger than that of the elderly group. CSA of C4 was the largest whereas CSA of C7 was the smallest. Eccentricity values of C4 and C5 were significantly larger than those of other vertebral levels (P＜0.05). Linear correlation was established between CSA, AP and RL at C2~C7 segments. CONCLUSION The results allow for minimizing inter-subject variability using normalization, and thereby highlighting the importance of morphological parameters as biomarkers in the research of cervical spinal lesions.
Humans ; Female ; Male ; Retrospective Studies ; Middle Aged ; Adult ; Cervical Cord/anatomy & histology* ; Magnetic Resonance Imaging ; Young Adult ; Aged ; Cervical Vertebrae/anatomy & histology*

Objective:To observe the imaging features of extramacular retinoschisis (EMRS) and paravascular abnormalities (PVA) in myopic patients, and preliminary analyze the differences in age, best corrected visual acuity (BCVA), spherical equivalent (SE), axial length (AL), and subfoveal choroidal thickness (SFCT).Methods:A cross-sectional clinical study. A total of 60 myopia patients with EMRS who were admitted to Department of Ophthalmology of The First Affiliated Hospital of Zhengzhou University from January 2023 to June 2024 were included in the study. There were 18 male cases with 18 eyes and 42 female cases with 42 eyes. Age was (37.57±17.14) years; SE was (-10.76±4.66) D; AL was (28.36±1.87) mm. According to the characteristics of ultra-wide-angle optical coherence tomography images, PVA was divided into perivascular cysts (PC), perivascular microfolds (PM) and perivascular lamellar holes (PLH). According to the splitting level, EMRS can be divided into inner layer, middle layer and outer layer. According to SE, the affected eyes were divided into low myopia group, moderate myopia group and high myopia group. The occurrence of EMRS near optic disc, supratemporal, suprasal and subnasal, as well as the clinical characteristics of patients with EMRS at different locations, levels and forms of PVA were observed. Age, BCVA, SE, AL and SFCT of EMRS patients at different locations and levels were compared by independent sample t test. χ2 test or Fisher exact probability test were used to compare the categorical variables between groups. Results:In 60 eyes, EMRS were located in supratemporal, infratemporal, supranasal, subnasal, and paratopic discs in 36, 43, 15, 13, and 14 eyes, respectively. The EMRS in the inner and outer layers were 59 (98.3%, 59/60) and 35 (58.3%, 35/60) eyes, respectively. PVA was present in 47 eyes (78.3%, 47/60). Among them, PC, PM and PLH were 45, 39 and 18 eyes, respectively. The age of those with paratopic splitting was older than those without paratopic splitting ( t=2.720). Those with temporal splitting had worse BCVA and longer AL than those without splitting ( t=2.139, 2.119). Those with subnasal splitting had worse BCVA, higher myopia, longer AL and thinner SFCT than those without splitting. The differences were statistically significant ( t=2.926, -2.640, 2.635, -3.938; P<0.05). Compared with other types of EMRS, patients with inner EMRS had younger age ( t=-2.383), better BCVA ( t=-4.825), shorter AL ( t=-4.767), lower myopia ( t=4.791), and thicker SFCT ( t=4.791); patients with full-layer EMRS were older ( t=2.419), worse BCVA ( t=3.656), longer AL ( t=2.677), higher degree of myopia ( t=-2.755), and thinner SFCT ( t=-3.283), with statistical significance ( P<0.05). There was significant difference in SFCT among patients with or without PC ( t=-2.396, P<0.05). Compared with eyes without PM and PLH, eyes with PM had worse BCVA, longer AL, higher myopia, and thinner SFCT, and the differences were statistically significant (PM: t=2.514, 3.078, -2.811, -4.205; P<0.05; PLH: t=2.514, 2.992, -2.949, -1.773; P<0.05). Conclusions:EMRS primarily occurs in the temporal side, with the highest frequency in the inner layer. Patients with inner-layer EMRS are younger, have better BCVA, shorter AL, lower myopia, and thicker SFCT, whereas patients with full-layer EMRS exhibit the opposite characteristics.

Objective:To observe and analyze the imaging features of pathologic myopic paravascular abnormalities (PVA) and macular retinoschisis (MRS) and their relationship with clinical features.Methods:A retrospective case series study. A total of 371 eyes of 224 patients with pathological myopia with PVA and/or MRS diagnosed by examination in Department of Ophthalmology of the First Affiliated Hospital of Zhengzhou University from September 2021 to December 2023 were included in the study. There were 74 eyes in 48 males and 297 eyes in 176 females. Age were 54 (49, 61) years; equivalent spherical lens (SE) was -13.375 (-18.00,-10.00) D. Axial length (AL) was 29.84 (28.27, 31.24) mm. According to the features of ultra-wide-angle sweep source optical coherence tomography, PVA morphology was divided into blood vessels and paravascular microfolds, paravascular retinal cysts, paravascular retinal splits and paravascular lamellar macular holes. MRS was divided into inner layer, outer layer and mixed layer according to splitting level, and grouped accordingly. The presence of dome-shaped macula (DSM), internal and external lamellar macular hole, and full lamellar macular hole (FTMH) were recorded. According to whether PVA combined with MRS or not, the affected eyes were divided into PVA group and PVA combined with MRS group. According to whether MRS involved the fovea, the affected eyes were divided into two groups: MRS not involved the fovea group and MRS involved the fovea group. Mann-Whitney U test was used to compare age, SE and AL among different groups. Qualitative data were compared by χ2 test. Results:In 371 eyes, there were 120 eyes in the simple PVA group; in the MRS group, there were 251 eyes, of which 208 eyes were in the PVA combined with MRS group. There were 33, 27, 3, 14, 12, 56, 28, and 7 eyes with or without retinal detachment, choroidal neovascularization, DSM, preretinal membrane, and simple superficial detachment of neuroepithelium in inner lamina, outer lamina, and FTMH, respectively. In 328 eyes with PVA, blood vessels and paravascular microfolds, paravascular retinal cysts, paravascular retinal splits and paravascular lamellar macular holes were 151, 236, 202 and 72 eyes, respectively. There were 142 eyes with single lesion (43.29%, 142/328). There were 186 eyes with 2 or more lesions (56.71%, 186/328). There were 34 eyes in the inner MRS group, 92 eyes in the outer MRS group and 125 eyes in the mixed MRS group, respectively. It involved 155 eyes in the fovea group; 96 eyes in the fovea group were not involved. There were significant differences in the number of PVA eyes between the outer MRS group, the inner MRS group and the mixed MRS group ( χ2=30.614, 28.379; P<0.001). Compared with PVA group, PVA group combined with MRS group was more likely to have two or more PVA lesions, the difference was statistically significant ( χ2=30.535, P<0.001). Compared with the inner MRS group and mixed MRS group, the age of the simple PVA group was younger, and the age of the outer MRS group was older, and the differences were statistically significant ( P<0.05). Compared with the inner MRS group and the outer MRS group, the simple PVA group had short AL, less myopia and better optimal corrected visual acuity (BCVA), while the mixed MRS group had long AL, more myopia and worse BCVA, and the differences were statistically significant ( P<0.05). Compared with the PVA group and the inner MRS group, the fovea was more involved in the outer MRS group and the mixed MRS group, and the difference was statistically significant ( χ2=3.906, 10.836; P<0.05). Those with MRS involved in fovea were older, AL was longer, myopia was more severe, and BCVA was worse ( P<0.001). DSM-associated splits were less likely to involve macula ( P<0.001). Conclusion:PVA and MRS exhibit a variety of presentations, and their imaging features correlate with clinical features.

Objective:To compare and observe the fundus imaging characteristics of eyes with glucocorticoid-related central serous chorioretinopathy (CSC).Methods:A retrospective clinical study. A total of 149 CSC patients with 166 eyes diagnosed at Department of Ophthalmology of The First Affiliated Hospital of Zhengzhou University from March 2021 to October 2024 were included in the study. The duration of the disease from the appearance of symptoms to treatment was less than 3 months. All affected eyes underwent best-corrected visual acuity (BCVA), fundus color photography, swept-source optical coherence tomography (SS-OCT), and fundus fluorescein angiography (FFA) examinations. BCVA was tested using an international standard vision chart and converted into logarithm of the minimum angle of resolution (logMAR) visual acuity for statistical analysis. The SS-OCT instrument measured subfoveal choroidal thickness (SFCT), central macular thickness (CMT), choroidal vascular volume (CVV), and the width and height of flat irregular pigment epithelial detachment (FIPED). FIPED, subretinal fibrin, and choroidal layer strong reflective spots were identified from SS-OCTA B-scan images; multiple leakages (leak points >3) were identified from FFA images. Based on the presence or absence of a clear history of glucocorticoid administration before the onset, patients were divided into glucocorticoid-related and non-glucocorticoid-related groups, comprising 41 patients with 53 eyes and 108 patients with 113 eyes, respectively. Clinical and fundus imaging characteristics of the two groups were compared. The comparison of quantitative data between the two groups was performed using independent samples t test or non-parametric independent samples Wilcoxon test; the comparison of qualitative data was performed using χ2 test. Results:Compared with the non-glucocorticoid-related group, the glucocorticoid-related group had a smaller male-to-female ratio and a higher bilateral incidence, and the differences were statistically significant ( χ2=4.925, 17.849; P<0.05). The logMAR BCVA for the glucocorticoid-related and non-glucocorticoid-related groups were 0.45±0.33 and 0.21±0.21, respectively; SFCT were (644.43±131.91) and (507.26±121.79) μm; CMT were (389.51±233.45) and (362.59±140.85) μm; CVV were (4.44±1.07) and (3.67±0.82) mm 3; FIPED incidence were 58.49% (31/58) and 20.35% (23/113), respectively; FIPED width and height were (1 122.01±533.98) and (742.90±388.79) μm, and (99.13±92.17) and (33.01±15.99) μm; subretinal fibrin were observed in 24 (45.28%, 24/53) and 15 (13.27%, 15/113) eyes; choroidal strong reflections were found in 38 (71.70%, 38/53) and 45 (39.82%, 45/113) eyes; multiple leak points were identified in 35 (66.03%, 35/53) and 40 (35.40%, 40/113) eyes, respectively. Compared with the non-glucocorticoid-related group, the glucocorticoid-related group had worse BCVA ( Z=-4.984), thicker SFCT ( t=6.586), larger CVV ( t=5.160), higher incidence of FIPED ( χ2=23.908), and greater width and height of FIPED ( t=2.895, Z=-3.703). The glucocorticoid-related group also had a significantly increased incidence of subretinal fibrin, choroidal strong reflections, and multiple leak points, with all differences being statistically significant ( χ2=20.565, 14.663, 13.675; P<0.05); however, the comparison of CMT showed no statistically significant difference ( Z=-0.651, P>0.05). Conclusion:Compared with non-glucocorticoid-related CSC, glucocorticoid-related CSC patients have poorer vision, are more likely to affect both eyes, show no gender bias; choroidal vascular dilation is more significant, and damage to the outer retina and retinal pigment epithelium is more severe.

Objective:To investigate the relationship between single nucleotide polymorphisms (SNP) in the CHRM1 gene and genetic susceptibility to high myopia (HM) in the Han population of Henan Province. Methods:A retrospective case-control study. From January 2021 to April 2023, 576 HM patients (HM group) and 768 healthy volunteers (control group) were recruited from the Department of Ophthalmology, the First Affiliated Hospital of Zhengzhou University. All participants were of Han ethnicity from Henan Province. SNP data for the CHRM1 gene in the Northern Han Chinese population were downloaded from the 1000 Genomes Project Online Website, with screening criteria of Hardy-Weinberg equilibrium P>0.05 and minor allele frequency> 0.05. Haploview software was used to analyze HapMap genotypes, identifying 5 tagSNP: rs55885673, rs544978, rs56995061, rs1942499, and rs2075748. MassARRAY system was employed for genotyping the 5 tagSNP loci. The SHEsis online software was employed to analyze the distribution differences of genotypes and allele frequencies between the two groups. Linkage disequilibrium coefficient D' was used to evaluate the recombination events between SNP loci, and haplotypes with frequencies exceeding 3% were constructed for statistical analysis. Results:The age of the HM group was significantly lower than that of the control group ( t=18.515, P<0.05), while no significant difference was observed in gender distribution ( χ2=2.869, P=0.087). Compared with the control group, the HM group showed significantly higher frequencies of the C allele [odds ratio ( OR)=1.44, 95% confidence interval ( CI): 1.09-1.91, Pc=0.045)] and CC genotype ( OR=1.50, 95% CI: 1.11-2.02, Pc=0.038) at the rs56995061 locus, and significantly lower frequencies of the T allele ( OR=0.69, 95% CI: 0.52-0.91, Pc=0.045) and CT genotype ( OR=0.67, 95% CI: 0.49-0.91, Pc=0.045). Additionally, the CT genotype frequency at the rs2075748 locus was significantly lower in the HM group ( OR=0.66, 95% CI: 0.53-0.84, Pc=0.002). The haplotype G-T-A-A formed by rs55885673-rs56995061-rs1942499-rs544978 was significantly less frequent in the HM group ( OR=0.71, 95% CI: 0.54-0.94, P=0.170). Conclusions:The polymorphisms at the SNP loci rs56995061 and rs2075748 in the CHRM1 gene are associated with the genetic susceptibility to high myopia in the Chinese Han population. The G-T-A-A haplotype composed of rs55885673-rs56995061-rs1942499-rs544978 reduces the susceptibility to high myopia.

Objective:To compare the clinical and imaging characteristics of eyes with idiopathic focal choroidal excavation (FCE) and acquired FCE, and to preliminarily analyze the association of FCE with different fundus diseases.Methods:A retrospective clinical study. A total of 90 patients (93 eyes) diagnosed with FCE at the Ophthalmology Department of The First Affiliated Hospital of Zhengzhou University from March 2021 to May 2024 were included in the study. All affected eyes underwent best-corrected visual acuity (BCVA) testing, intraocular pressure (IOP) measurement, ophthalmoscope, fundus color photography, and swept-source optical coherence tomography (SS-OCT). SS-OCT was used to measure subfoveal choroidal thickness (SFCT), choroidal thickness at the temporal, nasal, and inferior margins of the FCE, as well as the maximum width and depth of the FCE. Based on the presence of concomitant fundus diseases, FCE cases were divided into an idiopathic FCE group (51 eyes) and an acquired FCE group (42 eyes). Clinical characteristics at the initial and final visits were compared between the two groups. Clinical features were also analyzed for acquired FCE eyes with different associated fundus diseases. A logistic regression model was used to identify potential risk factors for FCE coexisting with other fundus diseases.Results:Compared to the idiopathic FCE group, the acquired FCE group had significantly decreased BCVA ( Z=?8.290), significantly increased FCE width ( Z=?2.762), and significantly higher incidence rates of saucer-shaped FCE ( χ2=8.352) and ellipsoid zone disruption ( χ2=7.999). These differences were all statistically significant ( P<0.05). No significant differences were found between the two groups in age, gender distribution, IOP, foveal involvement, proportion of conforming FCE, retinal pigment epithelium-Bruch’s membrane rupture, presence of hyperreflective material under the excavation, presence of surrounding thick vessels, FCE depth, SFCT, or choroidal thickness at the inferior, temporal, and nasal margins of the FCE ( P>0.05). Logistic regression analysis revealed that FCE width (odds ratio=1.002, 95% confidence interval: 1.001-1.004, P=0.005) was the sole risk factor for FCE coexisting with other fundus complications. In both the idiopathic and acquired FCE groups, FCE depth and width remained relatively stable during follow-up. BCVA improved in the acquired FCE group after treatment. Conclusions:FCE can coexist with various fundus diseases. FCE width is the only risk factor for the development of other fundus complications in FCE-affected eyes. Treating retinal or choroidal diseases associated with acquired FCE can provide visual benefits to patients.

BACKGROUND:Cervical instability is a common orthopedic disease in young and middle-aged people,and is the early manifestation of cervical spondylosis,which has a great impact on the quality of life of patients.Therefore,early diagnosis of cervical instability to implement early intervention has positive clinical and social significance.OBJECTIVE:The clinical prediction model of cervical instability in young and middle-aged people was constructed based on machine learning to realize early screening of cervical instability in young and middle-aged people before X-ray examination.METHODS:From September 2022 to October 2023,155 young and middle-aged adults with cervical instability and 88 with non-cervical instability recruited through recruitment advertisements and spinal department outpatient of Wangjing Hospital,China Academy of Chinese Medical Sciences were selected as research subjects.The research subjects'general information,living and working habits,discomfort symptoms,visual analog scale score,Neck Disability Index,and 36-ltem Short Form Health Survey were collected on site based on questionnaires.The above information was used as predictive factors.After screening,six machine learning algorithms of Support Vector Machine,LightGBM,RandomForest,Logistic,AdaBoost,and XGBClassifier were used to train the model by ten-fold cross-validation method,and the clinical prediction model of cervical instability was constructed.Area under the curve was used as the main evaluation index.Univariate analysis was performed on the predictors,and SHAP method was used to rank the importance of the predictors.Correlation heat maps were used to show the degree of linear correlation between the predictors and the cervical instability.RESULTS AND CONCLUSION:(1)Among the six machine learning models,RandomForest model was chosen as the final prediction model,including nine predictors,such as age,body mass index,neck circumference/neck length,visual analog scale score,Neck Disability Index,bodily pain,general health,vitality,and mental health,area under the curve=0.725 4,and the calibration degree was good.It could be used as a reference tool for early screening of cervical instability in young and middle-aged people.(2)There were significant differences in age,visual analog scale score,Neck Disability Index,bodily pain,general health,and vitality between the two groups(P＜0.05).(3)The order of importance of predictors was age,Neck Disability Index,visual analog scale score,general health,body mass index,vitality,bodily pain,neck circumference/neck length,mental health,among which age,visual analog scale score,Neck Disability Index were positively correlated with cervical instability,while general health,body mass index,vitality,bodily pain,neck circumference/neck length,and mental health were negatively correlated with cervical instability.