A new strategy for imaging biomolecular events through interactions between liquid crystals and oil-in-water emulsions.

In this study, we demonstrate a new strategy to image biomolecular events through interactions between liquid crystals (LCs) and oil-in-water emulsions. The optical response had a dark appearance when a nematic LC, 4-cyano-4'-pentylbiphenyl (5CB), is in contact with emulsion droplets of glyceryl trioleate (GT). In contrast, the optical response had a bright appearance when 5CB is in contact with GT emulsions decorated with surfactants such as sodium oleate. Since lipase can hydrolyze GT and produce oleic acid, the optical response also displays a bright appearance after 5CB has been in contact with a mixture of lipase and GT emulsions. These results indicate the feasibility of monitoring biomolecular events through interactions between LCs and oil-in-water emulsions.

Using liquid crystals to report molecular interactions between cationic antimicrobial peptides and lipid membranes.

In this study, we develop a novel method for label-free and real-time imaging of molecular interactions between cationic antimicrobial peptides and lipid membranes using liquid crystals (LCs). The optical appearance of LCs changes from bright to dark after transferring phospholipids onto the aqueous/LC interface, representing an orientational transition of LCs from planar to homeotropic state. Bright domains are observed when an antimicrobial agent is in contact with the LC interface decorated with a lipid monolayer of negatively charged phospholipids, while, there is no change in the optical response when the antimicrobial agent is in contact with the LC interface decorated with neutral phospholipids. This approach holds great promise for studying membrane disruption or permeabilization caused by antimicrobial agents.

A real-world retrospective study of pelvic floor muscle training efficacy using an APP-based home device / 复旦学报（医学版）

Objective To retrospectively investigate the efficacy of pelvic floor muscle training(PFMT)using APP-based home device in the real-world scenario.Methods A retrospective survey was conducted among 171 000 Chinese female users over 18 years old who freely registered APP and performed PFMT using a domestic manufactured home device from Oct 1,2019 to Mar 31,2021.The Patient Global Impression of Improvement(PGI-I)questionnaires concerning pelvic floor general condition,sexual satisfaction and other three major symptoms related to pelvic floor muscle laxity such as stress urinary incontinence(SUI),pelvic organ prolapse(POP),and vaginal laxity(VL)were broadcast public online for users to self-assess the improvement.The vaginal muscle strength values prior and post training recorded by APP were also reported.All data were collected anonymously for further stratified analysis.Results A total of 984 valid questionnaires were collected by systematic sampling.The PGI-I scores of pelvic floor general condition(P=0.000 1),sexual satisfaction(P=0.009),SUI(P=0.000 1),POP(P=0.044)and VL(P=0.034)were statistically significant in users who reported to use the device for 3 months or more compared with those less than 3 months.In addition,the increase of vaginal muscle strength was related to the improvement of PGI-I scores in SUI and POP with statistical significance.There were no significant difference in subgroups such as age,education,parity,and delivery mode.Conclusion The subjective benefit of pelvic floor function-related symptoms and the improvement of vaginal muscle strength could be observed after PFMT for three months or more using APP-based home device in Chinese women in the real-world scenario.

The Clinical Effect of Pretreatment with Heat-sensitive Moxibustion on Primary Dysmenorrhea and Its Influence on Uterine Artery Blood Flow： A Randomized， Blinded Controlled Trial / 中医杂志

ObjectiveTo compare the clinical effect of heat-sensitive moxibustion before menstruation and since the first day of menstruation on primary dysmenorrhoea （PD）， thereby optimizing the clinical treatment plan. MethodsSixty patients with PD were randomly divided into pretreatment group （treated before menstruation） and conventional treatment group （treated since the first day of menstruation） of 30 cases each. For all patients， the area surrounded by bilateral Zigong （EX-CA1） and bilateral Guilai （ST 29） in the supine position， and that formed by bilateral Shenshu （BL 23） and Ciliao （BL 32） in the prone position were selected for circling moxibustion （2 min）， sparrow-pecking moxibustion （1 min）， and then moxibustion along the channels to stimulate the moxibustion sensation and obtain two heat-sensitive points with the best sensation for treatment. In the pretreatment group， moxibustion was applied 3-7 days before the onset of menstruation， and in the conventional treatment group， moxibustion was applied on the day of menstruation. Both groups were treated once daily for 7 days per menstrual cycle for 3 consecutive cycles. The clinical outcomes of the two groups were measured before and after treatment in terms of the COX menstrual pain symptom scale （CMSS） scores， visual analogue scale for pain （VAS） scores， and uterine artery hemodynamic indicators including blood pulsation index （PI） and resistance index （RI）， and the clinical effect was compared. ResultsAfter treatment， the CMSS scores， VAS scores， PI and RI in the two groups decreased， and lower scores were found in the pretreatment group （P＜0.05 or P＜0.01）. The total effective rate after treatment was 93.3% （28/30） in the pretreatment group， which was better than 73.3% （22/30） in the conventional treatment group （P＜0.05）. ConclusionThe clinical effect of heat-sensitive moxibustion before the menstruation for PD was better than that implemented since the first day of menstruation， by significantly improving the patients' dysmenorrhoea symptoms and uterine artery blood flow index.

Research advances in the clinical features and diagnosis and treatment of non-puerperal mastitis / 解放军医学杂志

Non-puerperal mastitis(NPM)is a group of chronic inflammatory diseases with breast pain,lumps,abscesses and sinus tracts/fistulas as the main clinical manifestations,which is easily confused with breast cancer or other benign breast diseases.NPM always leads to a long treatment cycle and high recurrence rate,which may cause a large economic and psychological burden to patients.At present,the etiology and pathogenesis of NPM are still unclear,but it has a certain correlation with immune abnormality,bacterial infection,hormone disorder and other factors.Although several diagnostic methods available,the diagnosis of NPM relies on histopathological examination mainly.The treatment methods of the disease include observation and follow-up,pharmacotherapy,surgical treatment,etc.,but there is still no unified standard for specific treatment timing and treatment selection.In view of the controversy over etiology and treatment selection of NPM,this paper comprehensively summarizes the latest research progress in disease characteristics,clinical diagnosis and treatment of NPM based on domestic and foreign literature,aiming to provide reference and inspiration for the selection of reasonable clinical diagnosis and treatment.

Contamination and antimicrobial resistance of Vibrio parahaemolyticus isolated from seafood in a place of Zhejiang Province / 上海预防医学

Objective:To understand the contamination and antimicrobial resistance of Vibrio parahaemolyticus in seafood sold in a place of Zhejiang Province， and to provide basic data for the prevention and control of food-borne diseases caused by V. parahaemolyticus. Methods:V. parahaemolyticus was isolated and identified from seafood according to GB 4789.7—2013 method. The virulence genes were identified by real-time fluorescent PCR， and the antimicrobial sensitivity test was performed by Kirby-Bauer method. Results:V. parahaemolyticus was isolated from 55 of 210 seafood samples. The detection rate was 26.19%， and the detection rates of different species were quite different. None of the 55 isolates contained virulence genes tdh and trh， while all isolates have species-specific genes tlh and toxR. Most isolates were resistant to ampicillin and amoxicillin， with the same antimicrobial resistance rate of 96.36%. All isolates were fully sensitive to ampicillin/sulbactam， tetracycline， ciprofloxacin， levofloxacin， loxacin and chloramphenicol. Conclusion:V. parahaemolyticus contamination is common in sold seafood. The antimicrobial resistance of the isolates has reached a certain level. Monitoring of the pollution status of V. parahaemolyticus in seafood should be strengthened and the aquaculture and clinical use of antibiotics should be standardized.

Induction of thoracic aortic dissection: a mini-review of β-aminopropionitrile-related mouse models / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Thoracic aortic dissection (TAD) is one of the most lethal aortic diseases due to its acute onset, rapid progress, and high rate of aortic rupture. The pathogenesis of TAD is not completely understood. In this mini-review, we introduce three emerging experimental mouse TAD models using β-aminopropionitrile (BAPN) alone, BAPN for a prolonged duration (four weeks) and then with added infusion of angiotensin II (AngII), or co-administration of BAPN and AngII chronically. We aim to provide insights into appropriate application of these three mouse models, thereby enhancing the understanding of the molecular mechanisms of TAD.

Gamma 3 nails combined with hollow compression screw fixation for intertrochanteric fracture of risky external wall type / 中华创伤骨科杂志

Objective:To evaluate Gamma 3 nails combined with hollow compression screw fixation in the treatment of intertrochanteric fracture of risky external wall type.Methods:From November 2015 to December 2017, 60 patients with intertrochanteric fracture of risky external wall type were treated at Department of Orthopaedic Surgery, Wuhan Fourth Hospital. Of them, 27 ones, 15 males and 12 females with an age of 57.5 years±16.2 years (group A), were fixated with Gamma 3 nails and hollow compression screws, including 14 cases of AO type of 31-A2.2 and 13 cases of AO type of 31-A2.3. The other 33 patients, 18 males and 15 females with an age of 59.3 years±15.1 years (group B), were fixated with Gamma 3 nails alone, including 17 cases of AO type of 31-A2.2 and 16 cases of AO type of 31-A2.3. The 2 groups were compared in terms of operation time, hospitalization time, intraoperative blood loss, weight-bearing time, fracture healing time, complications and Harris hip scores at the final follow-up.Results:The 2 groups were comparable due to insignificant differences between them in preoperative general data ( P>0.05). The 60 patients obtained an average follow-up of 22.6 months (from 12 to 36 months). There were no statistically significant differences in operation time, intraoperative blood loss or hospital stay between the 2 groups ( P>0.05). Group A had a significantly lower incidence of external wall redisplacement [7.4% (2/27)], significantly shorter weight-bearing time(5.4 weeks±1.0 weeks) and fracture healing time(18.3 weeks±3.9 weeks), and significantly higher Harris hip scores at the final follow-up (89.3±7.1) than group B did [24.2% (8/33), 7.4 weeks±1.3 weeks, 21.7 weeks±5.6 weeks and 79.5±8.3, respectively] (all P< 0.05). Follow-ups revealed no complications like femoral head cutting, implant breakage, deep vein thrombosis of lower limb, fat embolism, hip varus deformity or nail breakage in either group. Conclusion:In the treatment of intertrochanteric fracture of risky external wall type, compared with Gamma 3 nails alone, Gamma 3 nails combined with hollow compression screw fixation can avoid external wall displacement or fixation failure after external medullary fixation or intramedullary fixation alone but does not increase operation time or intraoperative blood loss, leading to better functional recovery.

Induction of thoracic aortic dissection: a mini-review of β-aminopropionitrile-related mouse models / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Thoracic aortic dissection (TAD) is one of the most lethal aortic diseases due to its acute onset, rapid progress, and high rate of aortic rupture. The pathogenesis of TAD is not completely understood. In this mini-review, we introduce three emerging experimental mouse TAD models using β-aminopropionitrile (BAPN) alone, BAPN for a prolonged duration (four weeks) and then with added infusion of angiotensin II (AngII), or co-administration of BAPN and AngII chronically. We aim to provide insights into appropriate application of these three mouse models, thereby enhancing the understanding of the molecular mechanisms of TAD.

Evaluation of Kangli hollow screws with sliding compression locking plate system for treatment of femoral neck fractures / 中华创伤骨科杂志

Objective To evaluate Kangli hollow screws with sliding compression locking plate system (KHS) in the treatment of femoral neck fractures.Methods From February 2015 to October 2016,47 femoral neck fractures were treated at Department of Orthopaedics,Wuhan Fourth Hospital,Wuhan Puai Hospital Affiliated to Tongji Medical College,Huazhong University of Science and Technology.They were 30 men and 17 women,aged from 26 to 68 years (average,43.5 years).According to the Pauwels classification,there were 24 cases of type Ⅰ,16 cases of type Ⅱ and 7 cases of type Ⅲ;according to the Garden classification,there were 23 cases of type Ⅱ,19 cases of type Ⅲ and 5 cases of type Ⅳ.All the fractures were immobilized with KHS after closed reduction or open reduction (3 cases).The fracture union time,femoral head necrosis and femoral neck shortening were observed after operation.The Harris scores were used to evaluate therapeutic effects at the final follow-up.Results All the patients were followed up for an average of 29.7 months (from 22 to 39 months).All the fractures obtained solid bony union after 9 to 15 weeks (average,12.2 weeks).Femoral head necrosis occurred in one case (2.1％).Femoral neck shortening ≤ 5 mm was observed in 6 cases and femoral neck shortening ＞ 5 mm ＜ 10 mm in 2 cases,giving a total shortening rate of 17.0％.The Harris scores at the final follow-up ranged from 77 to 98 points,averaging 92.2 points.There were 42 excellent,3 good and 2 moderate cases,giving an excellent and good rate of 95.7％.Conclusion KHS can lead to excellent therapeutic effects in the treatment of femoral neck fractures.

Evaluation of Kangli hollow screws with sliding compression locking plate system for treatment of femoral neck fractures / 中华创伤骨科杂志

Objective@#To evaluate Kangli hollow screws with sliding compression locking plate system (KHS) in the treatment of femoral neck fractures.@*Methods@#From February 2015 to October 2016, 47 femoral neck fractures were treated at Department of Orthopaedics, Wuhan Fourth Hospital, Wuhan Puai Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology. They were 30 men and 17 women, aged from 26 to 68 years (average, 43.5 years). According to the Pauwels classification, there were 24 cases of type Ⅰ, 16 cases of type Ⅱ and 7 cases of type Ⅲ; according to the Garden classification, there were 23 cases of type Ⅱ, 19 cases of type Ⅲ and 5 cases of type Ⅳ. All the fractures were immobilized with KHS after closed reduction or open reduction (3 cases). The fracture union time, femoral head necrosis and femoral neck shortening were observed after operation. The Harris scores were used to evaluate therapeutic effects at the final follow-up.@*Results@#All the patients were followed up for an average of 29.7 months (from 22 to 39 months). All the fractures obtained solid bony union after 9 to 15 weeks(average, 12.2 weeks). Femoral head necrosis occurred in one case (2.1%). Femoral neck shortening ≤ 5 mm was observed in 6 cases and femoral neck shortening >5 mm <10 mm in 2 cases, giving a total shortening rate of 17.0%. The Harris scores at the final follow-up ranged from 77 to 98 points, averaging 92.2 points. There were 42 excellent, 3 good and 2 moderate cases, giving an excellent and good rate of 95.7%.@*Conclusion@#KHS can lead to excellent therapeutic effects in the treatment of femoral neck fractures.

Epidemiological research of risk factors for hypertension in north Fujian rural area／ / 心血管康复医学杂志

To study and analyze prevalence condition of hypertension and complicated cardiovascular risk factors in north Fujian rural area .Methods : By cluster sampling , an epidemiological questionnaire and physical ex‐amination were performed among 1784 residents using standardized survey method , who were ≥35 years from six towns and eight villages in north Fujian rural area from Jun 2013 to Mar 2014. Hypertension was diagnosed accord‐ing to The 2010 Chinese Guideline for the Prevention and Treatment of Hypertension , multivariate Logistic regres‐sion was used to analyze independent risk factors for hypertension in these subjects .Results : Prevalence rate of hy‐ pertension was 17.43% (31／1784 ) in north Fujian rural area .After population standardization , it＇s 23. 21%(18.66% in men and 16. 13% in women) , there was no significant difference in prevalence rate of hypertension be‐tween men and women in any age layer , P＞0. 05 all.Multivariate Logistic regression analysis indicated that age , overweight (BMI≥24 kg／m2 ) , high triglyceride and fasting blood glucose were independent risk factors for hyper‐tension in north Fujian rural area (OR＝1.107－2.096 , P＜0. 05 or ＜0. 01).Conclusion : Prevalence rate of hyper‐tension is high in north Fujian rural area , age , overweight , smoking , high triglyceride and fasting blood glucose are the main risk factors .

Clinical effect of individualized dose of rivaroxaban for thrombus prevention after hip arthroplasty / 重庆医学

Objective To explore the efficacy and safety of adjusting rivaroxaban dose for preventing deep vein thrombosis(DVT) according to extreme body mass in the patients with orthopedic surgery.Methods One hundred and two patients undergoing the first time total hip arthroplasty(THA) from January 2014 to December 2016 included 102 cases of body mass ＜50 kg and 27 cases of body mass ＞100 kg,which were divided into the experimental subgroup and control subgroup respectively.Each subgroup was given different doses of rivaroxaban for 35 d.The coagulation function,hemoglobin,D-dimer change,bleeding events and VTE incidence rate were recorded.Results The extension values of PT and APTT had no statistically significant difference between the experimental group and control group(P＞0.05).Hb and PLT in the ＜50 kg group were decreased,and the incision drainage amount was less than that in the ＜50 kg group,the intra-group comparison in the ＞100 kg group had no statistical difference (P＞0.05).All cases had no bleeding in other sites.The difference of DVT and PE occurrence had no statistical significance(P＞0.05).Conclusion Adjusting the rivaroxaban dose according to the extreme body mass can effectively prevent the DVT occurrence after orthopedic operation and reduces the occurrence rate of adverse drug reactions.

Treatment of Seinsheimer type Ⅲ subtrochanteric femoral fractures with prolonged Gamma3 nails and titanium wire fixation in the aged patients / 中华创伤骨科杂志

Objective To investigate the treatment of subtrochanteric femoral fractures of Sein-sheimer type Ⅲ with prolonged Gamma3 nails and titanium wire fixation in the aged patients. Methods From October 2014 to December 2015, 23 old patients with subtrochanteric femoral fracture were treated with prolonged Gamma3 nails and titanium wire fixation. They were 7 men and 16 women, aged from 62 to 78 years ( 69. 3 years on average ) . By Seinsheimer classification, 14 cases were type ⅢA and 9 type ⅢB. The time from injury to surgery averaged 3. 4 days ( from 2 to 6 days ) . Their operation time, intraoperative bleeding, hospital stay, fracture union time and hip function at the final follow-up were documented. Results Their operation time averaged 1. 3 hours ( from 1. 0 to 1. 6 hours ) , intraoperative bleeding 161 mL ( from 115 to 215 mL ) , and hospital stay 10. 7 days ( from 9 to 12 days ) . They obtained follow-ups from 5 to 12 months ( 9. 3 months on average ) . All the fractures achieved bony union after an average of 15. 4 weeks ( from 12 to 20 weeks ) . The function of the affected hip assessed at the final follow-up according to the Harris scoring was excellent in 15 cases, good in 5 and fair in 3, resulting in an excellent to good rate of 87. 0％. Their follow-ups revealed no deep venous thrombosis of lower limb, fat embolism, coxa vara, refracture, cut-in of the femoral head by the lag screw, or implant breakage. Conclusions In the treatment of senile subtrochanteric femoral fractures of Seinsheimer type Ⅲ, prolonged Gamma3 nails and titanium wire fixation exhibits advan-tages of limited operative trauma, rigid fixation, a high rate of union and limited complications. Additionally, this treatment can increase the accuracy of inserting distal locking nails, shorten operation time and improve functional recovery.

Orientational behaviors of liquid crystals coupled to chitosan-disrupted phospholipid membranes at the aqueous-liquid crystal interface.

In this study, we investigated the orientational behavior of liquid crystals (LCs) which is associated with the chitosan-disrupted phospholipid membrane at the aqueous/LC interface. The optical response of LCs changed from dark to bright after the transfer of an aqueous solution of chitosan onto the LC interface decorated with self-assembled monolayers of a negatively charged phospholipid, dioleoyl-sn-glycero-3-phospho-rac-(1-glycerol) sodium salt (DOPG). The chitosan-lipid interactions induced a rearrangement of the membrane, and thus, resulted in an orientational transition of LCs from a homeotropic to a planar state, thereby triggering a dark-to-bright shift in the optical response. We observed that LCs exhibited a bright-to-dark shift after an aqueous solution of lysozyme was transferred onto the chitosan-disrupted membrane, which implied that an enzymatic reaction between lysozyme and chitosan took place. We found that the addition of bovine serum album (BSA) induced a bright-to-dark change in the optical response; while LCs remained to appear bright after the transfer of chymotrypsin onto the aqueous/LC interface. We then further examined the interactions between other polyelectrolytes and phospholipid membranes.

Value of VFM technique in determination of left ventricular flow energy loss in different phases and segments in hypertensive patients / 心血管康复医学杂志

Objective:To explore value of vector flow mapping (VFM) technique in quantitative determination of left ventricular flow energy loss (LVFEL) in different phases and segments in hypertensive patients.Methods:A total of 130 hypertensive patients treated in our hospital from Jan 2014 to Jan 2017 were enrolled as hypertension group.Another 130 healthy subjects undergoing physical examination simultaneously were enrolled as healthy control group.According to clinical pattern,hypertension group was further divided into normal structure group (NS group,n＝40),concentric remodeling group (CR group,n＝ 56) and concentric hypertrophy group (CH group,n＝34).LVFEL of different phases and segments were measured and compared by VFM technique among all groups.Re-sults:LVFELs of different phases and segments in hypertension group were significantly higher than those of health-y control group,P＝0.001 all.Compared with NS group,there were significant rise in [ (15.10 ± 1.22) N·m-1· s-1vs.(17.94 ± 1.28) N·m-1·s-1vs.(16.76 ± 1.24) N·m-1·s-1] in CR group and CH group,and that of CR group was significantly higher than that of CH group,P＝0.001 all;compared with NS group and CH group,there was significant rise in middle segment flow EL [ (8.10 ± 1.20) N· m-1·s-1,(8.22 ± 1.18) N· m-1· s-1vs.(8.94 ± 1.16) N· m-1·s-1] in CR group,P＜ 0.01 all;apical segment flow EL of CH group was significantly higher than that of NS group [ (4.59 ± 1.07) N·m-1·s-1vs.(3.91 ± 1.09) N·m-1·s-1],P＝0.006;mid-di-astolic flow EL of CR group was significantly higher than that of NS group [ (8.87 ± 1.03) N·m-1·s-1vs.(8.25 ± 1.05) N·m-1·s-1],P＝0.006.Conclusion:Vector flow mapping technique can accurately and quantitatively determine LVFEL in different phases and segments in hypertensive patients,which provides reliable evidence for early revealing hemodynamic changes.

Euthyphoria reduction combined with percutaneous iliosacral screw fixation for irreducible sacroiliac dislocation / 中华创伤骨科杂志

Objective To evaluate euthyphoria reduction combined with percutaneous iliosacral screw fixation in the treatment of irreducible sacroiliac dislocation.Methods From March 2012 to May 2015,29 patients with irreducible sacroiliac dislocation were treated using euthyphoria reduction followed by percutaneous iliosacral screw fixation.They were 18 men and 11 women,aged from 25 to 68 years (average,37.9 years).According to the Tile classification,there were 7 cases of type Cl,9 cases of type C2,and 13 cases of type C3.The intervals from injury to surgery ranged from 6 to 32 days (average,11.3 days).Results The operation time for this cohort ranged from 40 to 125 minutes (average,76.2 minutes).The intraoperative bleeding ranged from 50 to 360 mL (average,148.6 mL).Their follow-ups ranged from 24 to 41 months (average,28.9 months).According to the Matta criteria for reduction,20 cases were rated as excellent and 9 as good,yielding an excellent to good rate of 100％.Their Majeed scores at the final follow-up averaged 90.1 points (range,from 67 to 100 points),giving 20 excellent,7 good and 2 fair cases (with an excellent to good rate of 93.1％).No screw loosening or lameness of the affected limb was observed during follow-ups.Conclusions Euthyphoria reduction combined with percutaneous iliosacral screw fixation can lead to satisfactory outcomes in the treatment of irreducible sacroiliac dislocation.Additionally it may improve operative safety.

Biomechanical comparison of Kangli hollow screws with sliding compression locking plate system and conventional cannulated lag screws for fixation of type Pauwels Ⅲ femoral neck fracture / 中华骨科杂志

Objective To compare the biomechanical performance of Kangli hollow screws with sliding compression locking plate system (KHS) and conventional cannulated lag screws for fixation of type Pauwels Ⅲ femoral neck fracture.Methods 7 cadaveric femurs were selected,vertical fractures (Pauwels Ⅲ fracture,at 70° to the horizontal) were artificially conducted in these cadaveric proximal femurs by an orthopaedic surgeon and fixed by KHS screws with plate system or conventional cannulated lag screws.Samples were positioned at 75° of the femoral shaft to the horizontal,embedded in the mould and fixed in the experimental console.Optical sensors were set at the femoral neck around the osteotomy line.Then the loading were input in the vertical,horizontal lateral direction and rotating direction around the femoral neck axis,the maximal and minimal values between the fractured fragments and the corresponding values of the loading were recorded.The values of stiffness in three directions were calculated and compared.The CT data of the left femur of a 25 year-old healthy male volunteer was input into the co(m)esponding software and vertical femoral neck fracture model was generated.Two finite element analysis models were obtained after the fracture being fixed using these two different implants,and the Von Mises stress distribution on the femur,implants and the interface between the fractured fragments and the relative motion between the fractured fragments were compared.Results In the vertical,horizontal lateral direction and rotating direction around the femoral neck axis,the stiffness of the KHS were 3 904±1 148 N/mm,4 324±1 234 N/mm and 11.45±4.95 N · m/° respectively,higher than those of the CSs method with the values of 3 020±1 150 N/mm,3 020± 854 N/mm.and 6.53±4.83 N· m/° respectively.The differences between the two groups were statistically significant (t=2.7194,4.7694 and 2.9424;P=0.0347,0.0050 and 0.0423).In the finite element analysis test,the maximal Von Mises stress values distributing on the femur and the screws in the KHS group were 40.1 MPa and 126.4 MPa,and those in the CSs group were 98.1 MPa and 145.5 MPa respectively,and both values of the former were lower than the latter.But the Von Mises stress value on the interface between the fractured fragments in the KHS group was 14.37 MPa,which was much higher than that in the CSs groupwhich was 9.39 MPa.The gap at the fracture site of the CSs fixation model was dramatically larger than that of KHS fixation model.Conclusion The KHS screws and plate system could provide better immobilization effect for vertical femoral neck fracture compared to the cannulated lag screws.The risk of the screws failure was lower and the fracture union would be easier to obtained by the fixation of KHS screws with plate system.

Using liquid crystals for the label-free detection of catalase at aqueous-LC interfaces.

In this study, we developed a simple label-free method for the detection of catalase (CAT) using liquid crystals (LCs). The optical appearance of LCs changed from bright to dark when hydrogen peroxide was in contact with the dodecanal-doped nematic LC, 4-cyano-4'-pentylbiphenyl (5CB). Since hydrogen peroxide can oxidize aldehyde into carboxylic acid, an orientational transition of the LC from the planar to homeotropic state was induced by the self-assembled carboxylate monolayer formed at the aqueous/LC interface. The optical response of LCs exhibited a higher sensitivity to the presence of hydrogen peroxide in an alkaline solution. A new type of LC-based sensor was developed to monitor the presence of CAT in the aqueous phase. Due to the enzymatically catalytic hydrolysis of hydrogen peroxide, the bright-to-dark shift in the optical signal did not take place in the aqueous mixture of hydrogen peroxide and catalase. In contrast, the optical response changed from bright to dark when the mixture in the optical cell was replaced with an aqueous solution of hydrogen peroxide. Considering the optical response of LCs related to the absence and presence of hydrogen peroxide, the aldehyde-doped 5CB might have potential utility in real-time recognition and detection of chemical and biological events associated with hydrogen peroxide.

Imaging trypsin activity through changes in the orientation of liquid crystals coupled to the interactions between a polyelectrolyte and a phospholipid layer.

In this study, we developed a new type of liquid crystal (LC)-based sensor for the real-time and label-free monitoring of enzymatic activity through changes in the orientation of LCs coupled to the interactions between polyelectrolyte and phospholipid. The LCs changed from dark to bright after an aqueous solution of poly-l-lysine (PLL) was transferred onto a self-assembled monolayer of the phospholipid, dioleoyl-sn-glycero-3-phospho-rac-(1-glycerol) sodium salt (DOPG), at the aqueous/LC interface. Interactions between the positively charged PLL and the negatively charged DOPG drove the reorganization of the phospholipid membrane, which induced an orientational transition in the LCs from a homeotropic to planar state. Since the serine endopeptidase trypsin can enzymatically catalyze the hydrolysis of PLL, the dark-to-bright shift in the optical response was not observed after transferring a mixed solution of PLL and trypsin onto the DOPG-decorated LC interface, indicating that no orientational transitions in the LCs occurred. However, the optical response from dark to bright was observed when the mixture in the optical cell was replaced by an aqueous solution of PLL. Control experiments with trypsin or an aqueous mixture of PLL and deactivated trypsin further confirmed the feasibility of this approach. The detection limit of trypsin was determined to be ~1 µg/mL. This approach holds great promise for use in the development of LC-based sensors for the detection of enzymatic reactions in cases where the biological polyelectrolyte substrates of enzymes could disrupt the organization of the membrane and induce orientational transitions of LCs at the aqueous/LC interface.