Immobilized enzyme-based enzyme electrode biosensors, characterized by high sensitivity and efficiency, strong specificity, and compact size, demonstrate broad application prospects in life science research, disease diagnosis and monitoring, etc. Immobilization of enzyme is a critical step in determining the performance (stability, sensitivity, and reproducibility) of the biosensors. Random immobilization (physical adsorption, covalent cross-linking, etc.) can easily bring about problems, such as decreased enzyme activity and relatively unstable immobilization. Whereas, directional immobilization utilizing amino acid residue mutation, affinity peptide fusion, or nucleotide-specific binding to restrict the orientation of the enzymes provides new possibilities to solve the problems caused by random immobilization. In this paper, the principles, advantages and disadvantages and the application progress of enzyme electrode biosensors of different directional immobilization strategies for enzyme molecular sensing elements by specific amino acids (lysine, histidine, cysteine, unnatural amino acid) with functional groups introduced based on site-specific mutation, affinity peptides (gold binding peptides, carbon binding peptides, carbohydrate binding domains) fused through genetic engineering, and specific binding between nucleotides and target enzymes (proteins) were reviewed, and the application fields, advantages and limitations of various immobilized enzyme interface characterization techniques were discussed, hoping to provide theoretical and technical guidance for the creation of high-performance enzyme sensing elements and the manufacture of enzyme electrode sensors.

Objective To analyze the stress changes of thoracic vertebra(T)11-sacrum(S)titanium rods in patients with ankylosing spondylitis after vertebral column decancellation(VCD)osteotomy,and provide reference for the selection and improvement of titanium rods before surgery.Methods The original data of the continuous scanning tomographic images of patients with ankylosing spondylitis after VCD osteotomy were imported into Mimics 21.0 in DICOM format,and T11-S vertebrae,screws and titanium rods were respectively reconstructed.They were imported into 3-Matic to establish a preliminary geometric modeling,and then processed with noise removal,paving,smoothing,etc.The improved model was imported into Hypermesh 10 software for grid division,and the material was imported into ANSYS 19.2 to display the finite element model after attribute assignment,Set the boundary and load conditions,and measure the stress value at the connection between the screw and the titanium rod.Results Under neutral position,forward bending,lateral bending,and axial rotation conditions,the titanium rod had the highest stress at the upper vertebrae(T11)and the lowest stress at the top vertebrae(L3);Under the backward extension condition,the titanium rod has the highest stress at the lower end vertebra(L5).Conclusion In the upper and lower vertebrae,it is possible to consider increasing the diameter of the titanium rod,enhancing its hardness,or changing it to a double rod.

Human brain banks use a standardized protocol to collect,process and store post-mortem human brains and related tissues,along with relevant clinical information,and to provide the tissue samples and data as a resource to foster neuroscience research according to a standardized operating protocols(SOP).Human brain bank serves as the foundation for neuroscience research and the diagnosis of neurological disorders,highlighting the crucial rule of ensuring the consistency of standardized quality for brain tissue samples.The first version of SOP in 2017 was published by the China Human Brain Bank Consortium.As members increases from different regions in China,a revised SOP was drafted by experts from the China Human Brain Bank Consortium to meet the growing demands for neuroscience research.The revised SOP places a strong emphasis on ethical standards,incorporates neuropathological evaluation of brain regions,and provides clarity on spinal cord sampling and pathological assessment.Notable enhancements in this updated version of the SOP include reinforced ethical guidelines,inclusion of matching controls in recruitment,and expansion of brain regions to be sampled for neuropathological evaluation.

The research progress in key technologies for dynamic perception of battlefield casualties was reviewed,including unmanned equipment dynamic mapping,dynamic environment semantic segmentation and casualty detection and identification.The discussion also covered the current state of research on casualty dynamic perception equipment in aerial and ground domains.The development trends of key technologies and equipment for dynamic perception of battlefield casualties were pointed out,and references were provided for enhancing the efficacy of battlefield casualty care and improving medical service support capabilities.[Chinese Medical Equipment Journal,2024,45(9):95-108]

Objective:To optimize the technical parameters related to the preparation of novel frozen human platelets and formulate corresponding protocol for its preparation.Methods:Novel frozen human platelets were prepared with O-type bagged platelet-rich plasma(PRP),the key technical parameters(DMSO addition,incubation time,centrifugation conditions,etc.)of the preparation process were optimized,and the quality of the frozen platelets was evaluated by routine blood tests,apoptosis rate,platelet activation rate and surface protein expression level.Results:In the preparation protocol of novel frozen human platelets,the operation of centrifugation to remove supernatant was adjusted to before the procedure of platelets freezing,and the effect of centrifugation on platelets was minimal when the centrifugation condition was 800 xg for 8 min.In addition,platelets incubated with DMSO for 30 min before centrifugation exhibited better quality after freezing and thawing.The indexes of novel frozen human platelets prepared with this protocol remained stable after long-term cryopreservation.Conclusion:The preparation technique of novel frozen human platelets was established and the protocol was formulated.It was also confirmed that the quality of frozen platelets could be improved by incubating platelets with DMSO for 30 min and then centrifuging them at 800 ×g for 8 min in the preparation of novel frozen human platelets.

Objective: To explore the clinical and imaging features of acute encephalopathy with biphasic seizures and late reduced diffusion(AESD) in children. Methods: For the case series study, 21 children with AESD from Peking University First Hospital, Provincial Children's Hospital Affiliated to Anhui Medical University, Children's Hospital of Fudan University, and Shanxi Children's Hospital who were diagnosed and treated from October 2021 to July 2023 were selected. Clinical data were collected to summarize their clinical information, imaging, and laboratory tests, as well as treatment and prognostic characteristics. Descriptive statistical analysis was applicated. Results: Of the 21 cases with AESD, 11 were males and 10 were females, with the age of onset of 2 years and 6 months (1 year and 7 months, 3 years and 6 months). Of the 21 cases, 18 were typical cases with biphasic seizures. All typical cases had early seizures within 24 hours before or after fever onset. Among them, 16 cases had generalized seizures, 2 cases had focal seizures, and 7 cases reached the status epilepticus. Of the 21 cases, 3 atypical cases had late seizures in biphasic only. The late seizures in the 21 cases occurred on days 3 to 9. The types of late seizures included focal seizures in 12 cases, generalized seizures in 6 cases, and both focal and generalized seizures in 3 cases. Diffusion-weighted imaging (DWI) test on days 3 to 11 showed reduced diffusion of subcortical white matter which was named "bright tree sign" in all cases. The diffuse cerebral atrophy predominantly presented in the front-parietal-temporal lobes was found in 19 cases between day 12 and 3 months after the onset of the disease. Among 21 cases, 20 had been misdiagnosed as autoimmune encephalitis, central nervous system infection, febrile convulsions, posterior reversible encephalopathy syndrome, acute disseminated encephalomyelitis, and hemiconvulsion-hemiplegia-epilepsy syndrome. All the cases received high-dose gammaglobulin and methylprednisolone pulse therapy with poor therapeutic effect. By July 2023, 18 cases were under follow-up. Among them, 17 cases were left with varying degrees of neurologic sequelae, including 11 cases with post-encephalopathic epilepsy; 1 recovered completely. Conclusions: AESD is characterized by biphasic seizures clinically and "bright tree sign" on DWI images. Symptomatic and supportive treatments are recommended. The immunotherapy is ineffective. The prognosis of AESD is poor, with a high incidence of neurological sequelae and a low mortality.
Male ; Female ; Child ; Humans ; Infant ; Child, Preschool ; Posterior Leukoencephalopathy Syndrome/complications* ; Seizures/etiology* ; Brain Diseases/diagnostic imaging* ; Status Epilepticus ; Seizures, Febrile/diagnostic imaging*

COVID-19 has been prevalent for three years. The virulence of SARS-CoV-2 is weaken as it mutates continuously. However, elderly patients, especially those with underlying diseases, are still at high risk of developing severe infections. With the continuous study of the molecular structure and pathogenic mechanism of SARS-CoV-2, antiviral drugs for COVID-19 have been successively marketed, and these anti-SARS-CoV-2 drugs can effectively reduce the severe rate and mortality of elderly patients. This article reviews the mechanism, clinical medication regimens, drug interactions and adverse reactions of five small molecule antiviral drugs currently approved for marketing in China, so as to provide advice for the clinical rational use of anti-SARS-CoV-2 in the elderly.

Ischemic stroke is the second leading cause of human death and the third reason of disability. Meanwhile, the incidence is rising year after year worldwide. Ischemic stroke could cause ischemia-reperfusion injury after blood recanalization treat-ment, but the mechanism of ischemia-reperfusion injury is still not very clear, so it is necessary to build a preclinical model with specific characteristics. Up to now, animal experiments have been still complicated, and the culture of brain slices has some limitations. The cell model in vitro has become a simplified and valuable tool widely used by researchers. The paper systematically summarizes the common type of nerve cells, and further analyzes establishment methods and principle, relevant research progress on the in vitro model of ischemia-reperfusion, in order to provide reference for rationally selecting hypoxia and reoxygenation model for basic research on cerebral ischemia and reperfusion and drug screening.

Aim To develop an UPLC-MS/MS method to determine the concentration of lorcaserin hydrochloride in beagle plasma, and study the pharmacokinetics of osmotic pump controlled-release tablets of lorcaserin hydrochloride. Methods A randomized crossover design was used, carbamazepine as the internal standard(IS), and plasma protein precipitation with acetonitrile. The chromatographic was Phenomenex Polar C18 column(100 mm×2. 1 mm, 3 μm), and acetonitrile - water(containing 10 mmol·L-1 ammonium acetate and 0.1% formic acid)(40:60, V/V)was mobile phase. Multiple reaction monitoring mode and electrospray positive ionization were used to detect lorcaserin hydrochloride. The MS/MS ion transitions were monitored at m/z 196.2→129.2 for lorcaserin hydrochloride and m/z 237→194.1 for carbamazepine, respectively. Results The linear range was 1 to 500 μg·L-1(r=0.999 2), the extraction recovery rate ranged from 87.70% to 89.70%, the precision RSD was 9.7%. The accuracy and matrix effect met the requirements, and the stability of lorcaserin hydrochloride was good in -20 ℃ refrigerator for 45 d, repeated freezing and thawing for three times, placed at room temperature for 24 h, and the disposed samples placed in automatsampler for 6 h were stable. The main pharmacokinetic parameters of the controlled-release tablet and immediate-release tablet were as follows:Tmax was(8.00±1.27)h and(1.00±0.13)h, Cmax was(70.56±3.73)μg·L-1 and(176.33±16.73)μg·L-1, and AUC0-t was(966.33±7.56)μg·h·L-1 and(973.05±69.09)μg·h·L-1, respectively. Conclusions The established UPLC-MS/MS method can be used to study the pharmacokinetics of lorcaserin hydrochloride in the plasma of beagle dogs, and osmotic pump controlled-release tablets has sustained release effect.

Femoral neck fracture (FNF) in the elderly patients is currently a major health challenge worldwide, with excessive consumption of medical resources, high incidence of complications as well as suboptimal outcome and prognosis. Hip joint arthroplasty (HJA) has been the mainstream treatment for FNF in the elderly, but the conventional surgical approaches and techniques are still confronted with a series of bottlenecks such as dislocation, limp and limb length discrepancy. In recent years, direct anterior approach (DAA) for HJA (DAA-HJA) has been a major new choice in the field of joint replacement, which achieves improved clinical effectiveness of HJA in the treatment of elderly FNF, due to the fact that DAA approach involves the neuromuscular interface and accords with the idea of soft tissue retention and enhanced recovery after surgery. However, there is still a lack of unified understanding of standard technique and procedure of DAA-HJA in the treatment of elderly FNF. Therefore, relevant experts from the Hip Joint Group of Chinese Orthopedics Association of Chinese Medical Association, Youth Arthrology Group of Orthopedic Committee of PLA, Orthopedic Committee of Chongqing Medical Association, Branch of Orthopedic Surgeons of Chongqing Medical Doctor Association and Sport Medicine Committee of Chongqing Medical Association were organized to formulate the " Chinese expert consensus on the technical standard of direct anterior hip arthroplasty for elderly femoral neck fracture ( version 2023)" based on evidence-based medicine. This consensus mainly proposed 13 recommendations covering indications, surgical plans, prosthesis selections, surgical techniques and processes, and postoperative management of DAA-HJA in elderly patients with FNF, aiming to promote standardized, systematic and patient-specific diagnosis and treatment to improve the functional prognosis of the patients.