This study aims to overcome the shortcomings such as low efficiency, high cost and difficult to carry out multi-parameter research, which limited the optimization of infusion bag configuration and manufacture technique by experiment method. We put forward a fluid cavity based finite element method, and it could be used to simulate the stress distribution and deformation process of infusion bag under external load. In this paper, numerical models of infusion bag with different sizes was built, and the fluid-solid coupling deformation process was calculated using the fluid cavity method in software ABAQUS subject to the same boundary conditions with the burst test. The peeling strength which was obtained from the peeling adhesion test was used as failure criterion. The calculated resultant force which makes the computed peeling stress reach the peeling strength was compared with experiment data, and the stress distribution was analyzed compared with the rupture process of burst test. The results showed that considering the errors caused by the difference of weak welding and eccentric load, the flow cavity based finite element method can accurately model the stress distribution and deformation process of infusion bag. It could be useful for the optimization of multi chamber infusion bag configuration and manufacture technique, leading to cost reduction and study efficiency improvement.
This study explored the variation of bursting force of multi-chamber infusion bag with different geometry size, providing guidance for its optimal design. Models of single-chamber infusion bag with different size were established. The finite element based on fluid cavity method was adopted to calculate the fluid-solid coupling deformation process of infusion bag to obtain corresponding critical bursting force. As a result, we proposed an empirical formula predicting the critical bursting force of one chamber infusion bag with specified geometry size. Besides, a theoretical analysis, which determines the force condition of three chamber infusion bag when falling from high altitude, was conducted. The proportion of force loaded on different chamber was gained. The results indicated that critical bursting force is positively related to the length and width of the chamber, and negatively related to the height of the chamber. While the infusion bag falling, the impact force loaded on each chamber is proportional to the total liquid within it. To raise the critical bursting force of in fusion bag, a greater length and width corresponding to reduced height are recommended considering the volume of liquid needed to be filled in.
It has been found for more than one century that when experiencing mechanical loading, the structure of bone will adapt to the changing mechanical environment, which is called bone remodeling. Bone remodeling is charaterized as two processes of bone formation and bone resorption. A large number of studies have confirmed that the shear stress is resulted from interstitial fluid flow within bone cavities under mechanical loading and it is the key factor of stimulating the biological responses of bone cells. This review summarizes the major research progress during the past years, including the biological response of bone cells under fluid flow, the pressure within bone cavities, the theoretical modeling, numerical simulation and experiments about fluid flow within bone, and finally analyzes and predicts the possible tendency in this field in the future.
Objective To determine the effectiveness of sodium hyaluronate (SHA) in preventing intraperitoneal (IP) adhesion. Methods Thirty-eight rats were randomly divided into A,B,C groups, normal saline, 6% Dextran-40 or SHA were applied on the present serosal injury respectively, during operation. Biopsy was taken on the 14th postoperative day.Results There were statistically significant differences in the extent of adhesion among three groups (Ｐ＜0.01). Mild inflammatory changes and less fibrous proliferation were found in group C by microscopy and decreased production of collagen (by fibroblast) and active mesothelial cells proliferation were observed in group C under electron microscope. Conclusion SHA appeares to reduce the extent of postoperative IP adhesion, which is more satisfactory than Dextran-40.
Objective To summarize experience and efficacy of multidisciplinary treatment for severe intra-abdominal infection. Methods The clinical data of 17 patients with severe intra-abdominal infection underwent multidisciplinary treatment were analyzed retrospectively. There were 5 cases of severe acute pancreatitis, 4 cases of postoperative biliary fistula, 2 cases of intestinal fistula, 2 cases of pancreatic trauma, 1 case after resection for intestinal necrosis, 1 case of abdominal trauma, 1 case after operation for liver abscess, 1 case of unexplained severe intra-abdominal infection. The experiences of multidisciplinary treatment including the intensive care unit (ICU), surgery, blood purification center, and departments of pharmacy, nutrition, and digestion and internal medicine, and so on were summarized. Results After multidisciplinary treatment, 13 patients were cured, of which 4 patients treated by non-open operation. Three patients died, including 1 patient died of infectious shock, 1 patient died of pancreatic bed bleeding, 1 patient died of multiple organ failure. There was 1 case of automatic discharge. Conclusions Multidisciplinary treatment including ICU, surgery, blood purification center, and departments of pharmacy, nutrition, and digestion and internal medicine, and so on has an exact clinical curative effect in patients with severe intra-abdominal infection. Concept of damage control should be followed by surgical intervention. Abdominal cavity puncture and drainage has some advantages of small trauma and good clinical effect, which is suitable for infection control of patients with severe intra-abdominal infection, it could provide surgical condition and opportunity for patients required further surgical treatment.
Objective To summarize the clinical experience of capture technology in the large diameter of abdominal aortic aneurysm in endovascular repair of abdominal aortic aneurysm(EVAR). Methods We retrospectively analyzed clinical data of 6 patients with abdominal aortic aneurysm (maximum diameter of 6.0 cm or bigger) in our hospital between July 2013 and May 2014.There were 3 males and 3 females at age of 76.2(73–81) years. Two patients of ruptured abdominal aortic aneurysm, in EVAR, established orbit using the capture technology successfully. Results The capture technology made the thread through the proximal tumor neck smoothly, successful repaired. One patient of rupture of abdominal aortic aneurysm was dead after 10 hours. One patient was lost to follow-up. Four patients were followed up for 3 to 11 months. The four patients had not occurred bracket displacement, internal leakage, thrombosis, or other serious complications. Conclusion For the patients with larger abdominal aortic aneurysm, capture technology may be used to the thread through the proximal tumor neck, to build a convey or track easily, to shorten the operation time, to improve the success rate of surgery.
Anti-vascular endothelial growth factor (VEGF) drugs have been widely used in clinic by inhibiting angiogenesis to treat ocular diseases such as malignant tumors and diabetic retinopathy. However, recent studies have shown that intravitreal injection of anti-VEGF drugs may have significant systemic absorption, leading to a series of renal damages such as worsening hypertension, proteinuria, new glomerular disease, and thrombotic microangiopathy. This article reviews the renal toxicity of intravitreal injection of anti-VEGF drugs in the treatment of diabetic retinopathy and other ocular diseases, aiming to provide recommendations for clinicians.
Objective To evaluate the results of the treatmenton femoral fractures with inverse limited marrow cavity rasping intramedullary interlocking nail . Methods From Jun. 1999 to Sep. 2003, 74 patients with femoralfractures were treated by intramedullary interlocking nail (inverse limited marrow cavity rasping) .There were 62 males and 12 females. Among them, 5 caseswere type 32A1, 7 cases were type 32A2, 12 cases were type 32A3, 35 cases were type 32B2, and 15 cases were type 32C2. Results Seventyfour patients were followed up for 13 to 29 months(15.4 months in average). Thetime for fracture union ranged from 3 to 5 months(3.8 months in average). The overall rate of excellence was 98.7% by Wuyuesong grading. There was 1 case of non-union, 1 case of delayed infection, and 2 cases of bent screw. Conclusion The treatment on femoral fractures with inverse limited marrow cavity rasping intramedullary interlocking nail is easy to operate and has minimum impairment to local circulation. It also promotes the healing and early function.
Objective To observe and analyze the risk factors of secondary intraocular hypertension in diabetic macular edema (DME) patients after treatment with dexamethasone vitreous cavity implant (DEX). MethodsA retrospective observational study. A total of 352 patients with type 2 diabetes mellitus (T2DM) secondary macular edema diagnosed by ophthalmic examination and treated with DEX in Department of Ophthalmology of Harbin 242 Hospital from January 2016 to March 2022 were included in the study. Among them, 221 were males and 131 were females, with the mean age of (55.56±8.09) years. There were 194 patients with disseminated macular edema, 158 patients with cystoid macular edema. All patients underwent vitreous cavity implantation of DEX. Intraocular pressure (IOP) was measured once a month for 3 months after treatment, with IOP over than 25 mm Hg (1 mm Hg=0.133 kPa) or higher than 10 mm Hg from baseline as secondary intraocular hypertension. The relevant clinical data were collected, and the risk factors of secondary intraocular hypertension in DME patients after DEX treatment were analyzed by binary logistic regression. ResultsAmong 352 patients, 116 patients (32.95%, 116/352) were in the intraocular hypertension. Among them, 29 patients (25.00%, 29/116), 69 patients (59.48%, 69/116) and 18 patients (15.52%, 18/116) occurred intraocular hypertension at 1, 2 and 3 months after treatment, respectively. Compared with the normal IOP group, the IOP in the intraocular hypertension group increased significantly at 1, 2 and 3 months after treatment, with statistical significance (t=10.771, 21.116, 13.761; P＜0.001). Compared with normal IOP group, the patients in the intraocular hypertension group had younger age (t=6.967), longer duration of diabetes (t=5.950), longer axial length (AL) (t=14.989), higher proportion of DME grade 3 (Z=6.284), higher proportion of DEX implantation in pars plana (χ2=23.275), and higher HbA1c level (t=10.764), the differences were statistically significant (P＜0.05). Logistic regression analysis showed that longer AL [odds ratio (OR)=1.428, 95% confidence interval (CI) 1.054-1.934], DEX implantation in pars plana (OR=1.358, 95%CI 1.063-1.735), and higher HbA1c (OR=1.702, 95%CI 1.225-2.366) were the risk factors for secondary intraocular hypertension in DME patients after DEX treatment (P＜0.05), older age was a protective factor (OR=0.548, 95%CI 0.380-0.789, P＜0.05). ConclusionsLong AL, DEX implantation in pars plana and high HbA1c are the risk factors for secondary intraocular hypertension after DEX treatment in DME patients, older age is a protective factor.
Objective To compare the effects of double-channel core decompression (CD) combined with medullary cavity irrigation with those of simple CD on progression of collapse and clinical outcomes in non-traumatic osteonecrosis of the femoral head (ONFH). Methods A retrospective analysis was conducted on the clinical data of 19 patients (30 hips) with non-traumatic ONFH who underwent double-channel CD combined with medullary cavity irrigation and admitted between January 2024 and October 2024 (CD+irrigation group). According to a 1: 2 ratio, 54 patients (60 hips) who underwent simple CD and were matched in terms of age, gender, and body mass index (BMI) were included as the control (CD group). There was no significant difference in baseline data such as age, gender, BMI, affected side, ONFH type, preoperative Association Research Circulation Osseous (ARCO) stage, bone marrow edema stage, visual analogue scale (VAS) score for pain, and Harris score between the two groups (P>0.05). The postoperative discharge time and occurrence of complications were recorded for both groups. The VAS scores before operation and at discharge after operation were compared, and the differences between pre- and post-operation (change values) were calculated for intergroup comparison. The Harris scores before operation and at discharge and 3 months after operation were also compared. During follow-up, X-ray film, CT, and MRI were performed for reexamination. The ARCO stage and bone marrow edema stage were evaluated at 3 months after operation and compared with those before operation to determine whether there was radiological progression or relief. Results All incisions in both groups healed by first intention after operation, with no infection, femoral neck fracture, or other operation-related complications. All patients were followed up, and the follow-up time of the CD+irrigation group was (146.8±27.7) days, and that of the CD group was (164.3±48.2) days; there was no significant difference between the two groups (t=1.840, P=0.069). There was no significant difference in the length of hospital stay between the two groups (P>0.05). At discharge after operation, the VAS score of the CD+irrigation group was significantly lower than that of the CD group (P<0.05), and the change value was significantly higher than that of the CD group (P<0.05). The Harris scores at discharge and 3 months after operation in the CD+irrigation group were significantly higher than those in the CD group (P<0.05). The Harris score gradually increased with time, and the differences between different time points were significant (P<0.05). Radiological reexamination showed that there was no significant difference in the ARCO stage and the incidence of radiological progression between the two groups at 3 months after operation (P>0.05); however, the bone marrow edema stage and the degree of bone marrow edema relief in the CD+irrigation group were better than those in the CD group, with significant differences (P<0.05).Conclusion Double-channel CD combined with medullary cavity irrigation can significantly alleviate hip joint pain and improve joint function in patients with non-traumatic ONFH, reduce the degree of bone marrow edema in the femoral head, and delay the progression of ONFH.