A Novel growth guidance system for early onset scoliosis: a preliminary in vitro study.

PURPOSE: The purpose of the study was to describe a novel growth guidance system, which can avoid metal debris and reduce the sliding friction forces, and test the durability and glidability of the system by in vitro test. METHOD: Two major modifications were made to the traditional Shilla system, including the use of ultra-high molecular weight polyethylene (UHMWPE) gaskets to avoid direct contact between the screw and rod, and polishing the surface of the sliding part of the rod. We tested the durability of the system by a fatigue test, which the samples were test on the MTS system for a 10 million cycle of a constant displacement. Pre and post-testing involved weighing the UHMWPE gaskets and observing the wear conditions. The sliding ability were measured by a sliding displacement test. The maximum sliding displacement of the system was measured after a 300 cycles of dynamic compressive loads in a sinusoidal waveform. RESULTS: After the fatigue test, all the UHMWPE gaskets samples showed some of the fretting on the edge of the inner sides, but its still isolated and avoided the friction between the screws and rods. There was no production of metallic fretting around the sliding screws and rods. The average wear mass of the UHMWPE gaskets was 0.002 ± 0.001 g, less than 1.7% of the original mass. In the sliding test, the novel growth guidance system demonstrated the best sliding ability, with an average maximum sliding distance(AMSD) of 35.75 ± 5.73 mm, significantly better than the group of the traditional Shilla technique(AMSD 3.65 ± 0.46 mm, P < 0.0001). CONCLUSION: In conclusion, we modified the Shilla technique and designed a novel growth guidance system by changing the friction interface of sliding screw and rod, which may significantly reduce the metallic debris and promote spine growth. The fatigue test and sliding dislocation test demonstrated the better durability and glidability of the system. An in vivo animal experiment should be performed to further verify the system.

High-performance electrosorption of lanthanum ion by Mn3O4-loaded phosphorus-doped porous carbon electrodes via capacitive deionization.

Transition-metal-oxide@heteroatom doped porous carbon composites have attracted considerable research interest because of their large theoretical adsorption capacity, excellent electrical conductivity and well-developed pore structure. Herein, Mn3O4-loaded phosphorus-doped porous carbon composites (Mn3O4@PC-900) were designed and fabricated for the electrosorption of La3+ in aqueous solutions. Due to the synergistic effect between Mn3O4 and PC-900, and the active sites provided by Mn-O-Mn, C/PO, C-P-O and Mn-OH, Mn3O4@PC-900 exhibits high electrosorption performance. The electrosorption value of Mn3O4@PC-900 was 45.34% higher than that of PC-900, reaching 93.02 mg g-1. Moreover, the adsorption selectivity reached 87.93% and 89.27% in La3+/Ca2+ and La3+/Na+ coexistence system, respectively. After 15 adsorption-desorption cycles, its adsorption capacity and retention rate were 50.34 mg g-1 and 54.12%, respectively. The electrosorption process is that La3+ first accesses the pores of Mn3O4@PC-900 to generate an electric double layer (EDL), and then undergoes further Faradaic reaction with Mn3O4 and phosphorus-containing functional groups through intercalation, surface adsorption and complexation. This work is hoped to offer a new idea for exploring transition-metal-oxide @ heteroatom doped porous carbon composites for separation and recovery of rare earth elements (REEs) by capacitive deionization.

Dual Growing Rods and the Apical Control Technique for Treating Congenital Early-Onset Scoliosis: Lessons Learned.

BACKGROUND: Congenital early-onset scoliosis (CEOS) is characterized by a spectrum of vertebral anomalies, including formation failures and segmentation failures at the apex segment, which makes CEOS different from other etiologies of early-onset scoliosis. To date, studies on patients who have graduated from CEOS treatment using traditional dual growing rods (TDGR) have been scarce, and the preliminary results of TDGR with or without the apical control technique (ACT) have varied. We therefore compared the final outcomes of patients with CEOS who graduated from TDGR with or without the ACT. METHODS: A retrospective study of patients with CEOS who had graduated from TDGR treatment performed from 2007 to 2020 was conducted. Graduation included final fusion or observation after reaching skeletal maturity. Patients were divided into the ACT-TDGR group (apical vertebrectomy and/or hemivertebrectomy with short fusion and TDGR) and the TDGR-only group. Demographic characteristics, radiographic data, patient-reported clinical outcomes, pulmonary function, and complications were analyzed. RESULTS: A total of 41 patients with CEOS were enrolled: 13 in the ACT-TDGR group and 28 in the TDGR-only group. The lengthening intervals were longer in the ACT-TDGR group (mean [and standard deviation], 1.26 ± 0.66 years) than in the TDGR-only group (0.80 ± 0.27 years). The preoperative main curve was larger in the ACT-TDGR group (80.53° ± 19.50°) than in the TDGR-only group (64.11° ± 17.50°). The residual curve was comparable between groups (26.31° ± 12.82° in the ACT-TDGR group compared with 27.76° ± 15.0° in the TDGR group) at the latest follow-up. The changes in apical vertebral rotation and thoracic rotation were significantly larger in the ACT-TDGR group. Patients had comparable T1-12 and T1-S1 heights, pulmonary function, and 22-item Scoliosis Research Society (SRS-22) scores at the latest follow-up. The mean number of mechanical-related complications per patient was lower in the ACT-TDGR group (0.77 ± 0.73) than in the TDGR-only group (1.54 ± 1.43). Seventeen patients underwent final fusion. CONCLUSIONS: In this small-scale study, we observed that both ACT-TDGR and TDGR-only could correct the deformity while allowing for spinal growth in patients with CEOS. ACT-TDGR yielded better correction in severe cases and did not have a deleterious effect on spinal height. A large number of cases will be needed to validate the clinical value of the ACT. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

[Preparation of Bamboo-based N, P Co-doped Activated Carbon and Its Lanthanum Ion Adsorption Performance].

Using diammonium hydrogen phosphate as an activator and N and P source and and bamboo chips as the carbon source, N, P co-doped activated carbon was prepared by one-step pyrolysis and used to efficiently remove La3+ in aqueous solutions. The effects of activation temperature and pH value on the adsorption performance of La3+ were analyzed, and the activation and adsorption mechanisms were explored using TG-IR, SEM-EDX, pore structure, XPS, and hydrophilicity. The results showed that diammonium hydrogen phosphate easily decomposed at a high temperature to produce ammonia and phosphoric acid, which activated the material and promoted the increase in the specific surface area and pore volume of the activated carbon. As an N and P source, the addition of diammonium hydrogen phosphate successfully achieved the N, P co-doping of activated carbon, and the introduction of N- and P-containing functional groups was the key to enhance the adsorption of La3+. Among them, graphitic nitrogen could provide interactions between La3+-π bonds, and C-P=O and C/P-O-P could provide active sites for the adsorption of La3+ through complexation and electrostatic interaction. The adsorption of La3+ on N, P co-doped activated carbons was endothermic and spontaneous, and the adsorption process conformed to the Langmuir isotherm and secondary kinetic model. Under the process conditions of an activation temperature of 900℃ and pH=6, the adsorption capacity of the N, P co-doped activated carbon was as high as 55.18 mg·g-1, which was 2.53 times higher than that of the undoped sample, and its adsorption selectivity for La3+ in the La3+/Na+and La3+/Ca2+ coexistence systems reached 93.49% and 82.49%, respectively. Additionally, the removal efficiency remained above 54% after five successive adsorption-desorption cycle experiments.

Traditional Dual Growing Rods With 2 Different Apical Control Techniques in the Treatment of Early-Onset Scoliosis.

OBJECTIVE: Based on traditional dual growing rods (TDGR), apical control techniques (ACTs) were introduced as adjuvant procedures to improve deformity correction at the apex segment in the treatment of early-onset scoliosis (EOS). We aimed to explore whether TDGR+ ACTs have different indications, attain more deformity correction, have negative effects on spinal growth, and have different complications. METHODS: Between 2004 and 2019, a retrospective study of EOS patients treated with TDGR with or without ACTs was conducted and divided into 3 groups: TDGR group; hybrid technique (HT) group: Vertebrectomy/hemivertebrectomy with short fusion and TDGR; ACPS group: apical convex control pedicle screws (ACPS) and TDGR. Demographic, radiographic parameters, clinical outcomes, complications, and revisions were analyzed and compared. RESULTS: Seventy-eight EOS patients were enrolled. The preoperative main curve was the largest in the HT group. ACPS group had the smallest residual curve (19° ± 8.9°) and apical vertebral translation (12.0 ± 9.0 mm) at the latest follow-up, followed by the HT group (30° ± 17.4°, 22.1 ± 13.4 mm) and TDGR group (30° ± 13.2°, 32.8 ± 17.1 mm). ACPS group had the largest T1-12 height and T1-S1 height after index surgery. Complications and revisions in the ACTs groups was lower than the TDGR group. Scoliosis Research Society-22 self-image questionnaire was superior in the ACPS group. CONCLUSION: According to our intermediate results, TDGR+ACTs could improve correction ability of apex deformity. ACTs had little deleterious effects on spinal height during the lengthening procedures, with a lower complication rate than TDGR. TDGR+ACTs might be a supplemental option for suitable EOS patients.

A time-resolved fluorescence immunoassay for rapid and precise automatic quality control of human papillomavirus type 68 VLPs in human papillomavirus vaccine.

The effectiveness and necessity of human papillomavirus (HPV) vaccination to prevent HPV infection and cervical cancer are increasingly recognized by people. The 15-valent HPV vaccine, which protects against almost high-risk types of HPV viruses identified by WHO, has attracted much attention. However, as the valence of vaccines increases, quality control in the HPV vaccine production process is facing more challenges. The precise quality control of the HPV type 68 virus-like particles (VLPs), one of the unique components of the 15-valent HPV vaccine that distinguishes it from existing vaccines, is the new requirement for vaccine manufacturers. Here we developed a novel time-resolved fluorescence immunoassay (TRFIA) for rapid and precise automatic quality control of HPV68 VLPs in HPV vaccine. Two murine monoclonal antibodies specifically targeting the HPV68 L1 protein were used to establish a classical sandwich assay. Except for pretreating the vaccine sample, the whole analysis process was performed by a fully automated machine, which saves detection time and gets rid of manual error. Multiple experiments established that the current novel TRFIA can efficiently and reliably analyses HPV68 VLPs. Present novel TRFIA has exhibited merits with speed, robustness, high sensitivity with a minimum detection value of 0.08 ng/mL, considerable accuracy, a wide detection range (up to 1000 ng/mL) and excellent specificity. It is also expected to provide a new detection method for quality control for each HPV type VLPs. To summarize, the novel TRFIA is of great interest for application in HPV vaccine quality control.

Ten-year trends in surgical management of 1207 congenital scoliosis.

PURPOSE: To report and analyze development trends in the surgical treatment of congenital scoliosis (CS) in a large CS cohort over a 10-year period. METHODS: We retrospectively searched and extracted medical records of CS inpatients receiving posterior instrumented fusion surgery at our institute from January 2010 to December 2019. We analyzed information on demographics and surgical information, including the surgical approach, number of fused segments, use of osteotomy and titanium cage implantation, length of stay, intraoperative blood loss, and rates of complications and readmission. RESULTS: 1207 CS inpatients were included. In the past decade, the proportion of patients younger than 5 years increased from 15.5 to 26.9%. The average number of fused segments decreased from 9.24 to 7.48, and the proportion of patients treated with short-segment fusion increased from 13.4 to 30.3%. The proportion of patients treated with osteotomy and titanium cage implantation increased from 55.65% and 12.03% to 76.5% and 40.22%. The average length of stay and blood loss decreased from 16.5 days and 816.1 ml to 13.5 days and 501.7 ml. The complication and readmission rates also decreased during these ten years. CONCLUSION: During this ten-year period, the surgical treatment of CS at our institute showed trends toward a younger age at fusion, lower number of fused segments, higher rate of osteotomy and titanium cage implantation, reduced blood loss, shorter length of stay and lower rate complications and readmission. These results suggest performing osteotomy combined with titanium cage implantation at an earlier age can achieve fewer fused segments and complications.

A custom-made time-resolved fluoroimmunoassay for the quantitation of the host cell protein of Vero in rabies vaccine.

Host cell proteins (HCPs) are the process-specific and inevitable impurities during the manufacture via a host cell, which affect the safety or efficacy of the bio-product. However, the commercial HCP enzyme-linked immunosorbent assay (ELISA) kits may not apply to specific products such as rabies vaccine from Vero cells. More advanced and process-specific assay methods are needed in the quality control of rabies vaccine throughout the whole manufacturing process. Therefore, a novel time-resolved fluoroimmunoassay (TRFIA) for the detection of process-specific HCP of Vero cells in rabies vaccine was established in this study. Liquid chromatography coupled tandem mass spectrometry (LC-MS/MS) was used during the preparation of HCP antigen. Based on a sandwich-type immunoassay format, analytes in samples were captured by one antibody coating in the wells and "sandwiched" by another antibody labeled with europium chelates. Due to the complex composition of HCP, both the capture and detected antibodies are polyclonal antibodies from the same anti-HCP antibodies pool. Multiple experiments have identified the optimal conditions to allow the valid and reliable detection of HCP in rabies vaccine. The TRFIA had a satisfactory limit of detection value (0.011 µg/ml) under optimal conditions, with the linear range from 0.0375 to 2.4 µg/ml of HCP. The coefficient variations (CVs) were all < 10%, and the recoveries were in the range of 97.00-102.42%. All the test results of Vero cell protein reference substance were included in the expected concentration, which demonstrated that the present method was available for the test of HCP in rabies vaccine. Based on these results, the novel TRFIA to detect HCP appears to be important for application in modern vaccine quality control during the whole manufacturing process.

Retrospective Analysis of Associated Anomalies in 636 Patients with Operatively Treated Congenital Scoliosis.

BACKGROUND: Congenital scoliosis is frequently associated with anomalies in multiple organ systems. However, the prevalence and distribution of associated anomalies remain unclear, and there is a large amount of variation in data among different studies. METHODS: Six hundred and thirty-six Chinese patients who had undergone scoliosis correction surgery at Peking Union Medical College Hospital from January 2012 to July 2019 were recruited, as a part of the Deciphering disorders Involving Scoliosis and COmorbidities (DISCO) study. The medical data for each subject were collected and analyzed. RESULTS: The mean age (and standard deviation) at the time of presentation for scoliosis was 6.4 ± 6.3 years, and the mean Cobb angle of the major curve was 60.8° ± 26.5°. Intraspinal abnormalities were found in 186 (30.3%) of 614 patients, with diastematomyelia being the most common anomaly (59.1%; 110 of 186). The prevalence of intraspinal abnormalities was remarkably higher in patients with failure of segmentation and mixed deformities than in patients with failure of formation (p < 0.001). Patients with intraspinal anomalies showed more severe deformities, including larger Cobb angles of the major curve (p < 0.001). We also demonstrated that cardiac anomalies were associated with remarkably worse pulmonary function, i.e., lower forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), and peak expiratory flow (PEF). Additionally, we identified associations among different concomitant malformations. We found that patients with musculoskeletal anomalies of types other than intraspinal and maxillofacial were 9.2 times more likely to have additional maxillofacial anomalies. CONCLUSIONS: In our cohort, comorbidities associated with congenital scoliosis occurred at a rate of 55%. To our knowledge, our study is the first to show that patients with congenital scoliosis and cardiac anomalies have reduced pulmonary function, as demonstrated by lower FEV1, FVC, and PEF. Moreover, the potential associations among concomitant anomalies revealed the importance of a comprehensive preoperative evaluation scheme. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Dual Growing Rods Combined With the Apical Convex Control Pedicle Screw Technique Versus Traditional Dual Growing Rods for the Surgical Treatment of Early-Onset Scoliosis: A Case-Matched 2-Year Study.

BACKGROUND: Combination of apical control convex pedicle screws (ACPS) with traditional dual growing rods (TDGRs) had better apex control ability for early-onset scoliosis (EOS); however, there is a paucity of studies on the ACPS technique. OBJECTIVE: To compare 3-dimensional deformity correction parameters and complications between the apical control technique (DGR + ACPS) and TDGR in the treatment of EOS. METHODS: A retrospective case-match analysis consisting of 12 cases of EOS treated with the DGR + ACPS technique (group A) from 2010 to 2020, and matched with TDGR case (group B) at a ratio of 1:1 by age, sex, curve type, major curve degree, and apical vertebral translation (AVT). Clinical assessment and radiological parameters were measured and compared. RESULTS: Demographic characteristics, preoperative main curve, and AVT were comparable between groups. The correction ability of the main curve, AVT, and apex vertebral rotation were better in group A at index surgery ( P < .05). The increase in T1-S1 and T1-T12 height was large in group A at index surgery ( P = .011, P = .074). The annual increase in spinal height was slower in group A, but without significant difference. The surgical time and estimated blood loss were comparable. Six complications occurred in group A, and 10 occurred in group B. CONCLUSION: In this preliminary study, ACPS seems to provide better correction of apex deformity, while attaining the comparable spinal height at 2-year follow-up. Larger cases and longer follow-up are needed to achieve reproducible and optimal results.

Clinical outcomes of the traditional dual growing rod technique combined with apical pedicle screws in the treatment of early-onset scoliosis: preliminary results from a single center.

OBJECTIVE: Limited control of an apical deformity is a major disadvantage in the traditional dual growing rod (TDGR) technique. Previous literature has reported the results of apical pedicle screw placement (APS) as an apical control technique in patients with early-onset scoliosis (EOS). However, the clinical outcomes, indications, and complications of the TDGR technique combined with APSs have not been well described. The purpose of this study was to evaluate the preliminary clinical outcomes of the TDGR technique combined with APSs in EOS patients. METHODS: Clinical data of 12 patients with EOS who were treated with the TDGR technique combined with APSs at the index surgery at the authors' center from January 2010 to January 2020, with a minimum 2-year follow-up, were retrospectively reviewed. Indications for the use of APSs included 1) no vertebral segmentation failure, fused ribs, or multiple hemivertebrae at the apex; 2) at least 2 normal discs around the apex; and 3) proper development of apical pedicles on the convex side. Etiology, age at index surgery, number of lengthening procedures, follow-up duration, and complications were recorded. Radiographic measurements included Cobb angle, apical vertebral translation (AVT), apical vertebral rotation (AVR), thoracic kyphosis, lumbar lordosis, spine height, and space available for the lung (SAL). RESULTS: The mean follow-up period was 4.0 ± 1.4 years, with a mean of 4.8 lengthening procedures per patient. The mean Cobb angle improved from 61.7° ± 10.4° to 19.9° ± 9.0° after the index surgery (19.6° ± 9.4° at the latest follow-up). The mean postindex AVT decreased to 16.8 ± 8.9 mm from a preindex AVT of 56.3 ± 9.7 mm and further improved to 13.6 ± 10.0 mm at the latest follow-up. The mean annual increases in T1-12 and T1-S1 height were 9.0 ± 4.7 mm and 13.9 ± 6.5 mm, respectively. The SAL improved from 0.91 to 1.04 at the latest follow-up. AVR improved significantly after the index surgery (p = 0.013), while minor deterioration was observed after repeat lengthening procedures. Five complications (2 implant related and 3 alignment related) occurred in 4 patients. CONCLUSIONS: For EOS patients with good flexibility (without segmentation failure or multiple hemivertebrae at the apex), the TDGR technique combined with APSs can improve primary curve correction, maintain good correction results, and allow continuous spine growth, which may reduce the risks of complications during lengthening treatment. More multicenter prospective studies with larger samples are needed to further validate the findings of this study.

Hybrid technique versus traditional dual growing rod technique to treat congenital early-onset scoliosis: a comparative study with more than 3 years of follow-up.

OBJECTIVE: The authors' objective was to compare the intermediate outcomes of patients with severe congenital early-onset scoliosis (CEOS) treated with posterior vertebrectomy/hemivertebrectomy with short fusion and dual growing rods (hybrid technique [HT]) and those treated with traditional dual growing rods (TDGRs). METHODS: A retrospective study of patients who underwent the HT and TDGR technique for CEOS was conducted. The inclusion criteria were CEOS (age < 10 years), Risser stage 0, treatment with HT or TDGR, index surgery performed between 2004 and 2017, and minimum follow-up of 3 years. For patients who completed lengthening procedures, the last lengthening procedure was considered the latest follow-up. Demographic, radiographic, clinical, and patient-reported outcomes and revisions were compared between groups. RESULTS: Sixty-one patients with CEOS were included in this study, with 16 treated with HT and 45 with TDGR technique. There were no differences in age at index surgery, duration of treatment, or number of lengthening procedures. The lengthening interval was longer in the HT group. The preoperative mean ± SD main curve was 81.8° ± 17.1° for the HT group and 63.3° ± 16.9° for the TDGR group (p < 0.05). However, main curve correction was better in the HT group, and no differences in residual curve were found between groups. Although the preoperative apex vertebral translation (AVT) of the HT group was greater, the correction of AVT was better in the HT group (p < 0.05). No differences in T1-S1 and T1-12 height were found between groups at the latest follow-up. The growth of T1-S1 height was less in the HT group (p < 0.05), whereas the growth of T1-12 height was similar between groups. Patients in the HT group had a lower risk of mechanical complications but higher risks of dural tears and neurological complications. CONCLUSIONS: HT may provide better correction and apex control ability than TDGR for EOS patients with severe and rigid deformity at the apex level, and it significantly decreased the risk of mechanical complications with little influence on growth of the thoracic spine. HT may be an option for patients with severe CEOS with large asymmetrical growth potential around the apex of the curve.

Lowest Instrumented Vertebra at L3 Versus L4 in Posterior Fusion for Moderate Lenke 5C Type Adolescent Idiopathic Scoliosis: A Case-Match Radiological Study.

OBJECTIVE: To compare the radiological outcomes in Lenke 5C type patients whose lowest instrumented vertebra (LIV) was L3 or L4 in a case-match study. METHODS: We conducted a retrospective case-match study and included 82 patients in the study. Radiological results before surgery, after surgery, and at last follow-up were recorded and analyzed in the L3 and L4 groups. RESULTS: After matching the age, Risser's sign, sex, and main Cobb, 41 pairs of patients were enrolled in our study. The total fusion segments in the L3 group (median [interquartile range]: 5.0 [6.0-5.0]) were shorter than those in the L4 group (6.0 [6.5-6.0]). The main curve was significantly corrected after surgery in both groups, and was comparable at the last followup between groups. In addition, according to the results of Fisher precision probability test, there was no significant difference of coronal or sagittal imbalance between the 2 groups at the 2-year follow-up. CONCLUSION: The correction in coronal and sagittal planes in L3 group and L4 group remains similar. On account of more motion segments, L3 could be an ideal choice as LIV in moderate Lenke 5C type AIS. Long-term follow-up is needed to evaluate the effect of larger compensatory lumbar-sacral curve when stopping at L3.

Ultrabright nanoparticle-labeled lateral flow immunoassay for detection of anti-SARS-CoV-2 neutralizing antibodies in human serum.

The level of anti-SARS-CoV-2 neutralizing antibodies (NAb) is an indispensable reference for evaluating the acquired protective immunity against SARS-CoV-2. Here, we established an ultrabright nanoparticles-based lateral flow immunoassay (LFIA) for one-step rapid semi-quantitative detection of anti-SARS-CoV-2 NAb in vaccinee's serum. Once embedded in polystyrene (PS) nanoparticles, the aggregation-induced emission (AIE) luminogen, AIE490, exhibited ultrabright fluorescence due to the rigidity of PS and severe inhibition of intramolecular motions. The ultrabright AIE490-PS nanoparticle was used as a fluorescent marker of LFIA. Upon optimized conditions including incubation time, concentrations of coated proteins and conjugated nanoparticles, amounts of antigens modified on the surface of nanoparticles, dilution rate of serum samples, and so on, the ultrabright nanoparticles-based LFIA could accurately identify 70 negative samples and 63 positive samples from human serum (p < 0.0001). The intra- and inter-assay precisions of the established method are above 13% and 16%, respectively. The established LFIA has tremendous practical value of generalization as a rapid semi-quantitative detection method of anti-SARS-CoV-2 NAb. Meanwhile, the AIE490-PS nanoparticle is also promising to detect many other analytes by altering the protein on the surface.

Dual-color quantum dot-loaded nanoparticles based lateral flow biosensor for the simultaneous detection of gastric cancer markers in a single test line.

A dual-color quantum dots-loaded nanoparticles (QPs) based lateral flow biosensor with single test line has been developed. Red and green emitted QPs were conjugated with antibodies and served as detecting probes in assays respectively, while the mixture of various antibodies were immobilized on nitrocellulose membranes as one detection line. Benefit from eliminating the heterogeneity caused by different position on the membrane, current biosensor achieved higher accuracy comparing with prevalent multi-lines or multi-strips lateral flow systems, which is of great significance for analyzing ratio-related diagnostics. The capability and reliability of the multiplex biosensor are also demonstrated by utilizing pepsinogen I (PG I) and pepsinogen II (PG II) as the model analytes. Under the optimal conditions, quantitative detection was achieved with ultra-low limits of detection at 6.9 pM (0.29 ng mL-1, PG I) and 15.7 pM (0.66 ng mL-1, PG II) respectively. The spectra crosstalk was negligible and no apparent cross-reaction was found in simultaneous detection. Furthermore, a good linear correlation of the QPs based lateral flow biosensor and commercial time-resolved fluoroimmunoassay was obtained in the detection of clinical samples, indicating the high reliability of the proposed biosensor.

Europium (III) chelate nanoparticle-based lateral flow immunoassay strips for rapid and quantitative detection of cystatin C in serum.

The concentration of Cys C in the patient's serum can reflect the level of glomerular filtration rate and indicate the occurrence of renal failure. The establishment of a simple and rapid analytical method to quantitatively monitor the concentration of Cys C in serum could help timely detection of renal failure. In this study, we have developed an Eu (III) chelate nanoparticles based lateral flow immunoassay to fulfill real-time monitoring of Cys C concentration in serum within 15 min. This method was performed as a sandwich immunoassay with a wide detection range (0.05-10 µg/mL) and a low limit of detection (24.54 ng/mL). The intra and inter-assay coefficients of variation were 8.31-8.61% and 8.92-9.95%, respectively. Furthermore, the application of this method was evaluated by comparing the determined results with those obtained by chemiluminescence immunoassay, exhibiting a satisfactory correlation (R2 = 0.9830). The developed LFIA method with satisfactory analytical performance has great potential for real-time monitoring of renal failure and self-detection for the high-risk population.

Rapid Monitoring of Vancomycin Concentration in Serum Using Europium (III) Chelate Nanoparticle-Based Lateral Flow Immunoassay.

Establishing personalized medication plans for patients to maximize therapeutic efficacy and minimize the toxicity of vancomycin (VAN) requires rapid, simple, and accurate monitoring of VAN concentration in body fluid. In this study, we have developed a simple and rapid analytical method by integrating Eu (III) chelate nanoparticles (CN-EUs) and lateral flow immunoassay (LFIA) to achieve the real-time monitoring of VAN concentration in serum within 15 min. This approach was performed on nitrocellulose (NC) membrane assembled LFIA strips via indirect competitive immunoassay and exhibited a wide linear range of detection (0.1-80 µg*ml-1) with a low limit of detection (69.2 ng*ml-1). The coefficients of variation (CV) of the intra- and inter-assay in the detection of VAN were 7.12-8.53% and 8.46-11.82%, respectively. The dilution test and specificity indicated this method had a stability that was not affected by the serum matrix and some other antibiotics. Furthermore, the applicability of the proposed method was assessed by comparing the determined results with those measured by LC-MS/MS, showing a satisfactory correlation (R 2 = 0.9713). The proposed CN-EUs-based LFIA manifested promising analytical performance, which showed potential value in the real-time monitoring of VAN and could help optimize the clinical use of more antibiotics.

A chemiluminescence immunoassay for precise automatic quality control of glycoprotein in human rabies vaccine.

Currently, quality control of glycoprotein in the human rabies vaccine is based on enzyme-linked immunosorbent assay (ELISA). However, ELISA does not match the needs of a modernised quality control system. For a long time, human rabies virus vaccine manufacturers have been devoted to seeking a detection platform that is sensitive, accurate, automatic, and feasible for practical applications. Therefore, our team invested major efforts into establishing a fully automated micromagnetic particle (MMP)-based chemiluminescence immunoassay (CLIA) platform. For vaccine quality control, MMP-coupled rabies virus glycoprotein monoclonal antibodies (S037) were used to capture the rabies virus. Another rabies virus glycoprotein antibody (S053) labelled with acridinium ester was added as a signal tracer. After pretreating the vaccine sample, the entire analysis was performed using a fully automated machine, which had a limited detection time (only 30 min) and eliminated manual error. Multiple experiments have identified the optimal conditions allowing valid and reliable assessment of vaccine potency. The CLIA platform has exhibited merits in terms of speed, robustness, high sensitivity (with a minimum detection value of 0.45 mIU/mL), considerable accuracy, and a wide linear range of detection (9.4-1200 mIU/mL). Furthermore, the results showed that the CLIA platform is consistent with the National Institutes of Health test and time-resolved fluorescent immunoassay (TRFIA) in quantitative analysis, and had a better analytic performance than TRFIA. Therefore, the CLIA platform presented here may be important for application in modern vaccine quality control.

Outcomes of Posterior Lumbar Hemivertebra Resection and Short Fusion in Patients With Severe Sacral Tilt.

OBJECTIVE: To introduce surgical strategies to restore coronal balance during limited fusion for early lumbar hemivertebra resection in patients with severe sacral tilt. METHODS: Sacral tilt was defined as a sacral tilt angle ≥ 5, and severe sacral tilt was defined as a sacral tilt angle > 10. From July 2004 to December 2017, 73 consecutive patients treated with posterior hemivertebra resection and short fusion in our institution were evaluated. Severe sacral tilt was noted in 26 patients (14 boys and 12 girls), and all were enrolled in this study. Undercorrection of the primary lumbar curve as compensation for the sacral tilt and short fusion was performed in these patients. The medical charts and imaging data of the patients were retrospectively reviewed to evaluate the outcomes. RESULTS: All patients were followed for at least 2 years. The mean age at the time of surgery was 3.7 (2-9) years old, with a total of 31 lumbar hemivertebra excised. On average, 2.8 (2-5) segments were fused for each patient. Sacral tilt minimally improved from 14.5° preoperatively to 13.6° postoperatively (p = 0.15) and remained stable at the follow-up. The overall lumbar curve was 41.9° preoperatively, 11.7° immediately postoperatively, and 14.6° at the final follow-up. The segmental scoliosis curve was 39.1° preoperatively, 9.7° immediately postoperatively, and 11.2° at the final follow-up. Segmental kyphosis was corrected from 27.2° to 6.5° after the surgery and was 7.1° at the latest follow-up. CONCLUSION: Sacral tilt is seen in patients with congenital scoliosis in lumbar hemivertebra. Undercorrection of the lumbar curve and segmental scoliosis to compensate for sacral tilt and short fusion after hemivertebra resection may be helpful to restore coronal balance and preserve mobility in segments in patients with pronounced severe sacral tilt.

Older fusion-surgery age in congenital scoliosis patients is a risk factor for extended length of stay, more estimated blood loss, longer fused segments and higher medical costs: a retrospective study.

BACKGROUND: Contradictory opinions about whether early correction and fusion surgeries should be performed for congenital scoliosis (CS) patients at a young age exist. The objectives of this study were to analyze the association between patient characteristics and fusion-surgery outcomes in CS patients treated with spinal correction and fusion surgeries and to report risk factors for extended length of stay (LOS), more estimated blood loss (EBL), longer fused segments and higher medical costs. METHODS: We analyzed data of 1,207 CS inpatients treated with fusion surgeries in our institute from January 2010 - December 2019. All patients underwent spinal X-ray, CT, MRI, echocardiogram and urogenital ultrasound. We analyzed demographic and clinical information and outcome measures, including LOS, EBL, fused segments and medical costs. RESULTS: Age at fusion (OR = 1.053; p < 0.001), musculoskeletal defects (OR = 1.670; p = 0.004) and thoracic deformity (OR = 1.519; p = 0.03) were risk factors for extended LOS. Age at fusion (OR = 1.117; p < 0.001), male sex (OR = 1.813; p < 0.001), mixed defects (OR = 1.662; p = 0.027) and failure of formation (OR = 1.718; p = 0.021) were risk factors for more EBL. Age at fusion (OR = 1.213; p < 0.001) was a risk factor for longer fused segments. Age at fusion (OR = 1.091; p < 0.001) and thoracic deformity (OR = 1.853; p = 0.004) were risk factors for higher medical costs. CONCLUSIONS: We found that older age at fusion in CS patients is a risk factor for extended LOS, more EBL, longer fused segments and higher medical costs with the risk increasing by 5-21 % for each year of age. Other identified risk factors include thoracic deformity for extended LOS; longer fused segments, higher medical costs, and musculoskeletal defects for extended LOS; and CS type (FF and MD) and sex (male) for more EBL.