Dynamic Optical Encryption Fueled via Tunable Mechanical Composite Micrograting Systems.

Optical grating devices based on micro/nanostructured functional surfaces are widely employed to precisely manipulate light propagation, which is significant for information technologies, optical data storage, and light sensors. However, the parameters of rigid periodic structures are difficult to tune after manufacturing, which seriously limits their capacity for in situ light manipulation. Here, a novel anti-eavesdropping, anti-damage, and anti-tamper dynamic optical encryption strategy are reported via tunable mechanical composite wrinkle micrograting encryption systems (MCWGES). By mechanically composing multiple in-situ tunable ordered wrinkle gratings, the dynamic keys with large space capacity are generated to obtain encrypted diffraction patterns, which can provide a higher level of security for the encrypted systems. Furthermore, a multiple grating cone diffraction model is proposed to reveal the dynamic optical encryption principle of MCWGES. Optical encryption communication using dynamic keys has the effect of preventing eavesdropping, damage, and tampering. This dynamic encryption method based on optical manipulation of wrinkle grating demonstrates the potential applications of micro/nanostructured functional surfaces in the field of information security.

Dynamically Rotating Magnetic Levitation to Characterize the Spatial Density Heterogeneity of Materials.

Magnetic levitation (MagLev) is a promising technology for density-based analysis and manipulation of nonmagnetic materials. One major limitation is that extant MagLev methods are based on the static balance of gravitational-magnetic forces, thereby leading to an inability to resolve interior differences in density. Here a new strategy called "dynamically rotating MagLev" is proposed, which combines centrifugal force and nonlinear magnetic force to amplify the interior differences in density. The design of the nonlinear magnetic force in tandem with centrifugal force supports the regulation of stable equilibriums, enabling different homogeneous objects to reach distinguishable equilibrium orientations. Without reducing the magnetic susceptibility, the dynamically rotating MagLev system can lead to a relatively large change in orientation angle (∆ψ > 50°) for the heterogeneous parts with small inclusions (volume fraction VF = 2.08%). The rich equilibrium states of levitating objects invoke the concept of levitation stability, which is employed, for the first time, to characterize the spatial density heterogeneity of objects. Exploiting the tunable nonlinear levitation behaviors of objects provides a new paradigm for developing operationally simple, nondestructive density heterogeneity characterization methods. Such methods have tremendous potential in applications related to sorting, orienting, and assembling objects in three dimensions.

[Effective substances and mechanism of Yishen Guluo Mixture in treatment of chronic glomerulonephritis based on metabolomics and serum pharmacochemistry].

This study aimed to investigate the effective substances and mechanism of Yishen Guluo Mixture in the treatment of chronic glomerulonephritis(CGN) based on metabolomics and serum pharmacochemistry. The rat model of CGN was induced by cationic bovine serum albumin(C-BSA). After intragastric administration of Yishen Guluo Mixture, the biochemical indexes related to renal function(24-hour urinary protein, serum urea nitrogen, and creatinine) were determined, and the efficacy evaluations such as histopathological observation were carried out. The serum biomarkers of Yishen Guluo Mixture in the treatment of CGN were screened out by ultra-performance liquid chromatography-quadrupole time-of-flight/mass spectrometry(UPLC-Q-TOF-MS) combined with multivariate statistical analysis, and the metabolic pathways were analyzed. According to the mass spectrum ion fragment information and metabolic pathway, the components absorbed into the blood(prototypes and metabolites) from Yishen Guluo Mixture were identified and analyzed by using PeakView 1.2 and MetabolitePilot 2.0.4. By integrating metabolomics and serum pharmacochemistry data, a mathematical model of correlation analysis between serum biomarkers and components absorbed into blood was constructed to screen out the potential effective substances of Yishen Guluo Mixture in the treatment of CGN. Yishen Guluo mixture significantly decreased the levels of 24-hour urinary protein, serum urea nitrogen, and creatinine in rats with CGN, and improved the pathological damage of the kidney tissue. Twenty serum biomarkers of Yishen Guluo Mixture in the treatment of CGN, such as arachidonic acid and lysophosphatidylcholine, were screened out, involving arachidonic acid metabolism, glycerol phosphatide metabolism, and other pathways. Based on the serum pharmacochemistry, 8 prototype components and 20 metabolites in the serum-containing Yishen Guluo Mixture were identified. According to the metabolomics and correlation analysis of serum pharmacochemistry, 12 compounds such as genistein absorbed into the blood from Yishen Guluo Mixture were selected as the potential effective substances for the treatment of CGN. Based on metabolomics and serum pharmacochemistry, the effective substances and mechanism of Yishen Guluo Mixture in the treatment of CGN are analyzed and explained in this study, which provides a new idea for the development of innovative traditional Chinese medicine for the treatment of CGN.

Surgical Management for Chronic Destructive Septic Hip Arthritis: Debridement, Antibiotics, and Single-Stage Replacement is as Effective as Two-Stage Arthroplasty.

OBJECTIVE: To compare the surgical outcomes of debridement, antibiotics, and single-stage total hip replacement (DASR) vs two-stage arthroplasty (two-stage arthroplasty) for chronic destructive septic hip arthritis (SHA). METHODS: Cases of chronic destructive SHA treated by DASR or two-stage arthroplasty in our department from January 2008 to October 2021 were retrospectively reviewed. Patient demographic information, perioperative inflammation markers, intraoperative blood loss, microbial culture, and metagenomic new generation sequencing results were recorded. The perioperative complications, hospital stay, hospitalization cost, infection recurrence rate, and Harris Hip Score (HHS) at the last follow-up were compared between the two groups. RESULTS: A total of 28 patients were included in the study, including 11 patients who received DASR and 17 patients who received two-stage arthroplasty. There was no significant difference in demographic information, preoperative serum inflammatory markers, synovial fluid white blood cell count, or percentage of polymorphonuclear leukocytes between the two groups. The DASR group demonstrated significantly lower intraoperative blood loss [(368.2 ± 253.3) mL vs (638.2 ± 170.0) mL, p = 0.002], hospital stay [(22.6 ± 8.1) days vs (43.5 ± 13.2) days, p < 0.0001], and hospitalization expenses [(81,269 ± 11,496) RMB vs (137,524 ± 25,516) RMB, p < 0.0001] than the two-stage arthroplasty group. In the DASR group, one patient had dislocation as a complication. There were no cases with recurrence of infection. In the two-stage arthroplasty group, there was one case complicated with spacer fracture, one case with spacer dislocation, and one case with deep vein thrombosis of the lower limbs. There were no cases with recurrence of infection. There were no significant differences in the readmission rate, complication rate, or HHS at the last follow-up between the two groups. CONCLUSIONS: Both DASR and two-stage arthroplasty achieved a satisfactory infection cure rate and functional recovery for chronic destructive SHA, and DASR demonstrated significantly lower intraoperative blood loss, hospital stay, and hospitalization costs than two-stage arthroplasty. For appropriately indicated patients, if microbial data are available and a standardized debridement protocol is strictly followed, DASR can be a treatment option.

Femtometer-amplitude imaging of coherent super high frequency vibrations in micromechanical resonators.

Dynamic measurement of femtometer-displacement vibrations in mechanical resonators at microwave frequencies is critical for a number of emerging high-impact technologies including 5G wireless communications and quantum state generation, storage, and transfer. However, the resolution of continuous-wave laser interferometry, the method most commonly used for imaging vibration wavefields, has been limited to vibration amplitudes just below a picometer at several gigahertz. This is insufficient for these technologies since vibration amplitudes precipitously decrease for increasing frequency. Here we present a stroboscopic optical sampling approach for the transduction of coherent super high frequency vibrations. Phase-sensitive absolute displacement detection with a noise floor of 55 fm/√Hz for frequencies up to 12 GHz is demonstrated, achieving higher bandwidth and significantly lower noise floor simultaneously compared to previous work. An acoustic microresonator with resonances above 10 GHz and displacements smaller than 70 fm is measured using the presented method to reveal complex mode superposition, dispersion, and anisotropic propagation.

Pump-free microfluidic magnetic levitation approach for density-based cell characterization.

Magnetic levitation (MagLev) provides a simple but promising method for density-based analysis and detection down to the individual cell level. However, each existing MagLev configuration for the single-cell density measurement, mainly consisting of a capillary (∼50 mm) placed between two magnets, yields a fairly low sample utilization because of no knowledge about the sample cells in the regions other than the limited microscope vision. Moreover, the quantitative analysis may be affected due to the unclearly defined measurement area, which is specifically associated with the uneven magnetization of magnets, cell size, degree of aggregation. In this work, we explore a pump-free microfluidic magnetic levitation approach for density-based cell characterization, enabling sensitive and effective cellular density measurement on small sample volumes. The microfluidic MagLev comprises a pump-free microfluidic chip placed between two ring magnets with like poles facing. With no external pumps, connectors or control facility, much smaller amounts of fluids (∼4 µL) could be driven automatically in the entire microchannel in 16 s. Based on the pump-free mechanism, unique density signatures of cells from different lineages (ARPE-19, HCT116, HeLa, HT1080, Huh7) are characterized by monitoring the levitation profiles. Furthermore, variation in density of A549 lung cancer cells subjected to a drug treatment are observed in our platform, allowing evaluation of the efficacy of the drug treatment at the individual cell level. Thereby, the proposed pump-free microfluidic MagLev platform, a low-cost, fully automatic and portable design for label-free density-based cell characterization, provides a universal detection tool that operates efficiently within small-volume environments.

[Effective substance and mechanism of Ziziphi Spinosae Semen extract in treatment of insomnia based on serum metabolomics and network pharmacology].

This study aims to study the effective substance and mechanism of Ziziphi Spinosae Semen extract in the treatment of insomnia based on serum metabolomics and network pharmacology. The rat insomnia model induced by p-chlorophenylalanine(PCPA) was established. After oral administration of Ziziphi Spinosae Semen extract, the general morphological observation, pentobarbital sodium-induced sleep test, and histopathological evaluation were carried out. The potential biomarkers of the extract in the treatment of insomnia were screened by ultra-high performance liquid chromatography-mass spectrometry(UHPLC-MS) combined with multivariate analysis, and the related metabolic pathways were further analyzed. The "component-target-pathway" network was constructed by ultra-high performance liquid chromatography coupled with quadrupole-Exactive mass spectrometry(UHPLC-Q-Exactive-MS/MS) combined with network pharmacology to explore the effective substances and mechanism of Ziziphi Spinosae Semen in the treatment of insomnia. The results of pentobarbital sodium-induced sleep test and histopathological evaluation(hematoxylin and eosin staining) showed that Ziziphi Spinosae Semen extract had good theraputic effect on insomnia. A total of 21 endogenous biomarkers of Ziziphi Spinosae Semen extract in the treatment of insomnia were screened out by serum metabolomics, and the metabolic pathways of phenylalanine, tyrosine and tryptophan biosynthesis, phenylalanine metabolism, and nicotinate and nicotinamide metabolism were obtained. A total of 34 chemical constituents were identified by UHPLC-Q-Exactive-MS/MS, including 24 flavonoids, 2 triterpenoid saponins, 4 alkaloids, 2 triterpenoid acids, and 2 fatty acids. The network pharmacological analysis showed that Ziziphi Spinosae Semen mainly acted on target proteins such as dopamine D2 receptor(DRD2), 5-hydroxytryptamine receptor 1 A(HTR1 A), and alpha-2 A adrenergic receptor(ADRA2 A) in the treatment of insomnia. It was closely related to neuroactive ligand-receptor interaction, serotonergic synapse, and calcium signaling pathway. Magnoflorine, N-nornuciferine, caaverine, oleic acid, palmitic acid, coclaurine, betulinic acid, and ceanothic acid in Ziziphi Spinosae Semen may be potential effective compounds in the treatment of insomnia. This study revealed that Ziziphi Spinosae Semen extract treated insomnia through multiple metabolic pathways and the overall correction of metabolic disorder profile in a multi-component, multi-target, and multi-channel manner. Briefly, this study lays a foundation for further research on the mechanism of Ziziphi Spinosae Semen in treating insomnia and provides support for the development of innovative Chinese drugs for the treatment of insomnia.

Salmonella Osteomyelitis in Adults: A Systematic Review.

The aim of this systematic review was to characterize the clinical features of adults with Salmonella osteomyelitis and summarize diagnosis and treatment methods to provide guidance for clinicians. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We conducted a literature search in the PubMed, EMBASE, and Cochrane Library databases. Article screening and data extraction were performed by two reviewers individually. All the included studies were independently evaluated by two reviewers using the Methodological Index for Non-Randomized Studies (MINORS) criteria. A total of 67 articles published between 1970 and 2019 were selected, which include 69 patients with an average age of 47.5 years (range, 18-79).The majority of cases (47.76%) occurred in immunocompetent adults without common risk factors. Aspiration and biopsy cultures were all positive in Salmonella osteomyelitis patients who underwent aspiration or biopsy. All infections were monomicrobial, and a total of 12 different serotypes were identified. The three most commonly reported Salmonella serotypes were Salmonella typhi (19 cases), Salmonella typhimurium (12 cases), and Salmonella enteritidis (11 cases). Only 12 of the 67 cases in our data (17.91%) had diarrhea symptoms, and 44 of the 67 cases (65.67%) had fever symptoms. Fifty-nine of the 67 cases (88.06%) had local inflammatory manifestations, such as erythema, swelling, and tenderness in the affected area. The commonly reported involved sites were the vertebrae, femur, and tibia. Antibiotic therapy alone was utilized in 30 cases, and 24 patients (80.00%) were eventually cured. In total, 75.68% of patients achieved satisfactory results after treatment with surgery and antibiotics. Third-generation cephalosporins were most commonly utilized, and antibiotic treatment was administered for an average of 11.3 weeks (95% CI, 8.31-14.37 weeks). Salmonella osteomyelitis should be considered in patients without any common risk factors. Aspiration or biopsy can facilitate the identification of pathogens to guide antibiotic choice. Empirical therapy with a third-generation cephalosporin is recommended until the susceptibility of the strain is determined.

Destination Joint Spacers: A Similar Infection-Relief Rate But Higher Complication Rate Compared with Two-Stage Revision.

OBJECTIVE: To evaluated the clinical outcomes of periprosthetic joint infection (PJI) patients with destination joint spacer compared with that of two-stage revision. METHODS: From January 2006 to December 2017, data of PJI patients who underwent implantation with antibiotic-impregnated cement spacers in our center due to chronic PJI were collected retrospectively. The diagnosis of PJI was based on the American Society for Musculoskeletal Infection (MSIS) criteria for PJI. One of the following must be met for diagnosis of PJI: a sinus tract communicating with the prosthesis; a pathogenis isolated by culture from two separate tissue or fluid samples obtained from the affected prosthetic joint; four of the following six criteria exist: (i) elevated ESR and CRP; (ii) elevate dsynovial fluid white blood cell (WBC) count; (iii) elevated synovial fluid neutrophil percentage (PMN%); (iv) presence of purulence in the affected joint; (v) isolation of a microorganism in one periprosthetic tissue or fluid culture; (vi) more than five neutrophilsper high-power fields in five high-power fields observed from histological analysis of periprosthetic tissue at ×400 magnification. Age, sex, body mass index (BMI), and laboratory test results were recorded. All patients were followed up regularly after surgery, the infection-relief rates were recorded, Harris hip score (HHS) and knee society score (KSS) were used for functional evaluation, a Doppler ultrasonography of the lower limb veins was performed for complication evaluation. The infection-relief rates and complications were compared between destination joint spacer group and two-stage revision group. RESULTS: A total of 62 patients who were diagnosed with chronic PJI were enrolled, with an age of 65.13 ± 9.94 (39-88) years. There were 21 cases in the destination joint spacer group and 41 cases in the temporary spacer group, namely, two-stage revision group (reimplantation of prosthesis after infection relief). The Charlson comorbidity index (CCI) in the destination joint spacer group was higher than that in the temporary spacer group, and this might be the primary reason for joint spacer retainment. As for infection-relief rate, there were three cases of recurrent infection (14.29%) in the destination joint spacer group and four cases of recurrent infection (9.76%) in the two-stage revision group, there were no significant differences with regard to infection-relief rate. Moreover, there two patients who suffered from spacer fractures, three cases of dislocation, one case of a periarticular fracture, and three cases of deep venous thrombosis in destination joint spacer group, while there was only one case of periprosthetic hip joint fracture, one case of dislocation, and one patient suffered from deep venous thrombosis of the lower extremity in two-stage revision. The incidence of complications in the destination joint spacer group was higher than that of two-stage revision. CONCLUSIONS: In summary, the present work showed that a destination joint spacer might be provided as a last resort for certain PJI patients due to similar infection-relief rate compared with two-stage revision.

Nonparametric Bayesian Prior Inducing Deep Network for Automatic Detection of Cognitive Status.

Pilots' brain fatigue status recognition faces two important issues. They are how to extract brain cognitive features and how to identify these fatigue characteristics. In this article, a gamma deep belief network is proposed to extract multilayer deep representations of high-dimensional cognitive data. The Dirichlet distributed connection weight vector is upsampled layer by layer in each iteration, and then the hidden units of the gamma distribution are downsampled. An effective upper and lower Gibbs sampler is formed to realize the automatic reasoning of the network structure. In order to extract the 3-D instantaneous time-frequency distribution spectrum of electroencephalogram (EEG) signals and avoid signal modal aliasing, this article also proposes a smoothed pseudo affine Wigner-Ville distribution method. Finally, experimental results show that our model achieves satisfactory results in terms of both recognition accuracy and stability.

Electrically Activated Soft Robots: Speed Up by Rolling.

Soft robots show excellent body compliance, adaptability, and mobility when coping with unstructured environments and human-robot interactions. However, the moving speed for soft locomotion robots is far from that of their rigid partners. Rolling locomotion can provide a promising solution for developing high-speed robots. Based on different rolling mechanisms, three rolling soft robot (RSR) prototypes with advantages of simplicity, lightweight, fast rolling speed, good compliance, and shock resistance are fabricated by using dielectric elastomer actuators. The experimental results demonstrate that the impulse-based and gravity-based RSRs can move both stably and continuously on the ground with a maximum speed higher than 1 blps (body length per second). The ballistic RSR exhibits a high rolling speed of ∼4.59 blps. And during its accelerating rolling process, the instantaneous rolling speed of the robot prototype reaches about 0.65 m/s (13.21 blps), which is much faster than most of the previously reported locomotion robots driven by soft responsive materials. The structure design and implementation methods based on different rolling mechanisms presented can provide guidance and inspiration for creating new, fast-moving, and hybrid mobility soft robots.

Rare Occurrence of Acute Hematogenous Periprosthetic Joint Infection Due to Fusobacterium Nucleatum in the Background of a Dental Procedure: A Case Report.

OBJECTIVE: Fusobacterium nucleatum is an anaerobic gram-negative bacilli that is one of the oral and other mucosal surface microbiota. It involves a wide range of human diseases and was first found in periodontal diseases, but reports of bone-related infections caused by F. nucleatum are rare, especially periprosthetic joint infections (PJI). METHODS: Here, we present the first case of acute hematogenous PJI of the hip joint caused by F. nucleatum, and debridement, antibiotics, and implant retention (DAIR) was performed. RESULTS: The patient was successfully treated with DAIR, identification of isolates by metagenomics next-generation sequencing was confirmed by polymerase chain reaction. CONCLUSIONS: For stable acute hematogenous PJI after hip replacement, quick and accurate diagnosis, the identification of pathogenic microorganisms, and the use of DAIR combined with sufficient sensitive antibiotics have a certain clinical effect and can achieve the purpose of both preserving the prosthesis and infection control.

Total Knee Arthroplasty in Patients with Unsuspected Tuberculosis of the Joint: A Report of Four Cases and a Systematic Review of the Literature.

OBJECTIVES: To provide a case series and systematic review that explores the clinical manifestations, treatments, and methods for defining tuberculosis diagnoses in patients who have undergone total knee arthroplasty (TKA). METHODS: Four patients (three women, one man; average age, 59.5 ± 8.89 years; range, 48-69 years) underwent TKA and were subsequently treated for previously unsuspected knee tuberculosis between January 2013 and December 2019. We also reviewed published cases of tuberculous periprosthetic joint infections (TBPJIs) following TKA through databases of MEDLINE/PubMed, the Cochrane Library, and EMBASE. We reviewed studies that were published between January 1980 and December 2019. RESULTS: In our four cases, the preoperative diagnoses were osteoarthritis (n = 2), rheumatoid arthritis (one case), and Charcot's arthropathy (one case). The main clinical manifestations were knee swelling and pain, without fever, weakness, or weight loss. Comorbidities included multiple joints with rheumatoid arthritis or Charcot's arthropathy, diabetes mellitus, and uremia. One patient had a history of lumbar tuberculosis treated with debridement and intervertebral fusion. Preoperative elevated erythrocyte sedimentation rates (ESRs) were detected in all cases, and elevated C-reactive protein (CRP) levels were observed in three cases. The tuberculosis diagnoses were confirmed via histopathologic analysis (three cases) and second-generation sequencing (one case). Three patients received antituberculosis therapy for 1 year, without surgical intervention. Two-stage exchange arthroplasty was performed in one patient because of prosthesis loosening. Within an average follow-up period of 24.75 months, tuberculosis reactivation was not observed and overall functional improvement was demonstrated. Forty-four TBPJI cases were reported in the literature between January 1980 and December 2019. Most (59.09%) occurred within the first year after the index arthroplasty, and the diagnoses were confirmed by culturing Mycobacterium tuberculosis in 88.64% of cases. Favorable outcomes were achieved in 90.91% of the patients who did not undergo surgery, 71.43% of those treated with debridement, 93.33% undergoing revision arthroplasty, and in 90.91% of those undergoing resection and arthrodesis. CONCLUSIONS: Clinical manifestations of knee tuberculosis and TBPJI are atypical. Thus, attention should be paid to finding the causes of increased ESRs and CRP levels, particularly in patients with weakened immune functioning, before performing TKA. Pathological examination is an effective method for diagnosing tuberculosis, although sending multiple specimens for pathological examination is necessary.

Pathogenic Detection by Metagenomic Next-Generation Sequencing in Osteoarticular Infections.

Objectives: To evaluate metagenomic next-generation sequencing (mNGS) as a diagnostic tool in detecting pathogens from osteoarticular infection (OAI) samples. Methods: 130 samples of joint fluid, sonicate fluid, and tissue were prospectively collected from 92 patients with OAI. The performance of mNGS and microbiology culture was compared pairwise. Results: The overall sensitivity of mNGS was 88.5% (115/130), significantly higher than that of microbiological culture, which had a sensitivity of 69.2% (90/130, p < 0.01). Sensitivity was significantly higher for joint fluid (mNGS: 86.7% vs. microbiology culture: 68.7%, p < 0.01) and sonicate fluid (mNGS: 100% vs. microbiology culture: 66.7%, p < 0.05) samples. mNGS detected 12 pathogenic strains undetected by microbiological culture. Additional pathogens detected by mNGS were Coagulase-negative Staphylococci, Gram-negative Bacillus, Streptococci, Anaerobe, non-tuberculosis mycobacterium, MTCP (p > 0.05), and Mycoplasma (OR = ∞, 95% confidence interval, 5.12-∞, p < 0.001). Additionally, sensitivity by mNGS was higher in antibiotic-treated samples compared to microbiological culture (89.7 vs. 61.5%, p < 0.01). Conclusions: mNGS is a robust diagnostic tool for pathogenic detection in samples from OAI patients, compared to routine cultures. The mNGS technique is particularly valuable to diagnose pathogens that are difficult to be cultured, or to test samples from patients previously treated with antibiotics.

Cup-Cage Solution for Massive Acetabular Defects: A Systematic Review and Meta-Analysis.

Our systematic review compiled multiple studies and evaluated survivorship and clinical outcomes of cup-cage construct usage in the management of massive acetabular bone defects. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Various combinations of "acetabular", "pelvis", "cup cage" and their corresponding synonyms were used to search relevant articles in the Cochrane, EMBASE, and PubMed databases. Basic information of the functional scores, implant revision rate, and complication rate were selected as outcomes for analysis. Finally, a total of 11 articles published between 1999 and 2019 were selected, which include 232 patients with an average age of 68.5 years (range, 30-90). The mean follow-up period was 48.85 months (range, 1-140). Our study shows that the cup-cage construct has a good clinical outcome with a low revision rate and a low complication rate. Improved clinical outcomes of cup-cage constructs were seen with a revision rate of 8% and an all-cause complication rate of 20%. The most commonly reported complication was dislocation, followed by aseptic loosening, infection, and nerve injuries. In summary, it is a promising method for managing large acetabular bone defects in total hip revision.

Debridement, Antibiotics, and Implant Retention for Acute Periprosthetic Joint Infection.

OBJECTIVE: To report on our clinical outcomes and on the experience of managing acute periprosthetic joint infection (PJI) with debridement, antibiotics, and implant retention (DAIR). METHODS: We performed a retrospective review of all patients who were diagnosed with acute PJI after primary hip or knee replacement surgeries and who were managed with DAIR in our prospective joint replacement registry from 2008 to 2019. The diagnosis of PJI was made according to the 2011 Musculoskeletal Infection Society (MSIS) criteria. The symptom onset duration, inflammatory marker levels (i.e. C-reactive protein [CRP], erythrocyte sedimentation rate [ESR], white cell count [WBC], and synovial WBC count), functional scores including the Knee Society Score (KSS), the KSS functional score and the Harris Hip Score (HHS), bacteriology, and surgical outcomes of the patients were tracked and recorded. A paired sample of joint fluid and tissues was also sent for a metagenomic next-generation sequencing (mNGS) test. A paired-samples t-test was used to compare the differences in the inflammatory markers and functional scores before and after surgery. RESULTS: A total of 24 patients with 7 infections after hip replacements and 17 infections after knee replacements were included. A total of 21 patients exhibited early postoperative infections, and 3 exhibited late acute hematogenous infections. During a mean follow-up time of 29.2 ± 15.1 months, 22 patients were successfully treated, whereas 2 patients were unsuccessfully treated and required repeated DAIR. The overall success rate of DAIR was 91.7%. For staphylococcal infections, DAIR had a 100% success rate. Five patients who presented with symptoms between 4 and 8 weeks also achieved a 100% success rate. At the last follow-up, the mean CRP level decreased from 52.6 ± 34.0 to 5.4 ± 3.5 (P < 0.001), and the mean ESR level decreased from 72.3 ± 34.3 to 20.2 ± 12.1 (P < 0.001). The mean KSS score increased from 44.8 ± 12.2 to 81.4 ± 9.2 (P < 0.001), and the mean KSS functional score increased from 38.1 ± 3.5 to 73.9 ± 23.0 (P < 0.001), and the mean HHS score increased from 34.4 ± 6.9 to 84.1 ± 15.1 (P < 0.001). The overall pathogen identification rate was 91.7% (22/24 cases). The success rates for Staphylococcus, Streptococcus, and the other pathogens were 100% (9/9 cases), 71.4% (5/7 cases), and 100% (6/6 cases), respectively. CONCLUSION: Debridement, antibiotics, and implant retention has a high success rate for the treatment of acute PJI and may be performed in selected patients whose symptoms have been sustained for over 4 weeks. A high rate of success for staphylococcal infections was reported with the use of DAIR.

Primary gastric melanoma: A case report with imaging findings and 5-year follow-up.

BACKGROUND: Most melanomas identified in the stomach are metastatic; primary gastric melanoma (PGM) is extremely rare, and the relevant studies are relatively scarce. PGM may be incorrectly diagnosed as other gastric malignant tumor types. CASE SUMMARY: We describe a rare case of PGM confirmed through long-term clinical observation and pathological diagnosis. A 67-year-old woman presented to our hospital with recurrent chest tightness and chest pain. Digital gastrointestinal radiography revealed a circular shadow in the gastric cardia. Computed tomography (CT) revealed a heterogeneous tumor with uneven enhancement. Enlarged lymph nodes were noted in the lesser curvature of the stomach. On magnetic resonance imaging (MRI), T1- and T2-weighted imaging revealed hyperintensity in and hypointensity in the tumor, respectively, both of which increased substantially after uneven enhancement. Near total gastrectomy was performed, and the tumor was pathologically confirmed to be a gastric melanoma. Because no other possible primary site of malignant melanoma was suspected, a clinical diagnosis of PGM was made. The patient was followed for nearly 5 years, during which she received CT reexamination, but no recurrence or metastasis was observed. CONCLUSION: Certain imaging characteristics could be revealed in PGM. Imaging examination can be of great value in preoperative diagnosis, differential diagnosis, and follow-up of patients with PGM.

Bioinspired Variable Stiffness Dielectric Elastomer Actuators with Large and Tunable Load Capacity.

This article proposes a bioinspired variable stiffness dielectric elastomer actuator (VSDEA) that is inspired by the leaf habit of monocots. The VSDEA is a fully flexible strip with a curved cross section and a tip dielectric elastomer minimum energy structure (DEMES). An arc fixture is used to clamp the strip that imitates the connection mode between the leaf and the cylindrical stem of the monocot. When applying voltage on the tip DEMES, the transverse curvature of the strip is changed, and then, the bending stiffness of the VSDEA can be tuned. Effects of applied voltage and important design parameters on the bending behavior of the VSDEA are experimentally studied in detail. The results show that the bending stiffness of the VSDEA approximately decreases linearly with the increase of applied voltage, which is very advantageous for stiffness control. The load capacity of the VSDEA is enhanced due to the bioinspired clamping mechanism and can be tuned by the applied voltage. It can also be found from the tested VSDEA prototypes that, when the applied voltage ranges from 0 V to 5.6 kV, the maximum relative stiffness and critical load changes reach about 71.8% and 75.6%, respectively. The maximum stiffness and critical load are, respectively, 157.8 N/m and 889.9 mN, which are two orders greater in magnitude than general DEMESs; as a result, this VSDEA can bear a payload 139 times its weight. It demonstrates that the bioinspired VSDEA can be useful for soft robots, vibration control, and morphing applications.

Tension-Induced Raman Enhancement of Graphene Membranes in the Stretched State.

The intensity ratio of the 2D band to the G band, I2D /IG , is a good criterion in selecting high quality monolayer graphene samples; however, the evaluation of the ultimate value of I2D /IG for intrinsic monolayer graphene is a challenging yet interesting issue. Here, an interesting tension-induced Raman enhancement phenomenon is reported in supported graphene membranes, which show a transition from the corrugated state to the stretched state in the vicinity of wells. The I2D /IG of substrate-supported graphene membranes near wells are significantly enhanced up to 16.74, which is the highest experimental value to the best of knowledge, increasing by more than 600% when the testing points approach the well edges.The macroscopic origin of this phenomenon is that corrugated graphene membranes are stretched by built-in tensions. A lattice dynamic model is proposed to successfully reveal the microscopic mechanism of this phenomenon. The theoretical results agree well with the experimental data, demonstrating that tensile stresses can depress the amplitude of in-plane vibration of sp2 -bonded carbon atoms and result in the decrease in the G band intensity. This work can be helpful in furthering the development of the method of suppressing small ripples in graphene and acquiring ultraflat 2D materials.

Transplantation of a Peripheral Nerve with Neural Stem Cells Plus Lithium Chloride Injection Promote the Recovery of Rat Spinal Cord Injury.

Transplantation of neural stem cells (NSCs) holds great potential for the treatment of spinal cord injury (SCI). However, transplanted NSCs poorly survive in the SCI environment. We injected NSCs into tibial nerve and transplanted tibial nerve into a hemisected spinal cord and investigated the effects of lithium chloride (LiCl) on the survival of spinal neurons, axonal regeneration, and functional recovery. Our results show that most of the transplanted NSCs expressed glial fibrillary acidic protein, while there was no obvious expression of nestin, neuronal nuclei, or acetyltransferase found in NSCs. LiCl treatment produced less macrosialin (ED1) expression and axonal degeneration in tibial nerve after NSC injection. Our results also show that a regimen of LiCl treatment promoted NSC differentiation into NF200-positive neurons with neurite extension into the host spinal cord. The combination of tibial nerve transplantation with NSCs and LiCl injection resulted in more host motoneurons surviving in the spinal cord, more regenerated axons in tibial nerve, less glial scar area, and decreased ED1 expression. We conclude that lithium may have therapeutic potential in cell replacement strategies for central nervous system injury due to its ability to promote survival and neuronal generation of grafted NSCs and reduced host immune reaction.