Longitudinal intravital imaging of the bone marrow for analysis of the race for the surface in a murine osteomyelitis model

Critical knowledge gaps of orthopedic infections pertain to bacterial colonization. The established dogma termed the Race for the Surface posits that contaminating bacteria compete with host cells for the implant post-op, which remains unproven without real-time in vivo evidence. Thus, we modified the murine longitudinal intravital imaging of the bone marrow (LIMB) system to allow real-time quantification of green fluorescent protein (GFP+) host cells and enhanced cyan fluorescent protein (ECFP+) or red fluorescent protein (RFP+) methicillin-resistant Staphylococcus aureus (MRSA) proximal to a transfemoral implant. Following inoculation with ~105 CFU, an L-shaped metal implant was press-fit through the lateral cortex at a 90° angle ~0.150 mm below a gradient refractive index (GRIN) lens. We empirically derived a volume of interest (VOI) = 0.0161 ± 0.000675 mm3 during each imaging session by aggregating the Z-stacks between the first (superior) and last (inferior) in-focus LIMB slice. LIMB postimplantation revealed very limited bacteria detection at 1 h, but by 3 h, 56.8% of the implant surface was covered by ECFP+ bacteria, and the rest were covered by GFP+ host cells. 3D volumetric rendering of the GFP+ and ECFP+ or RFP+ voxels demonstrated exponential MRSA growth between 3 and 6 h in the Z-plane, which was validated with cross-sectional ex vivo bacterial burden analyses demonstrating significant growth by ~2 × 104 CFU/h on the implant from 2 to 12 h post-op (p < 0.05; r2  > 0.98). Collectively, these results show the competition at the surface is completed by 3 h in this model and demonstrate the potential of LIMB to elucidate mechanisms of bacterial colonization, the host immune response, and the efficacy of antimicrobials.

[Research progress on exosomes and exosomal microRNAs in the occurrence and development of diabetic peripheral neuropathy]

Diabetic peripheral neuropathy (DPN) is one of the chronic complications of diabetic neuropathy, and also the main cause of chronic wounds and disability. Exosomes and exosomal-microRNAs (miRNAs) are closely related to DPN and participate in the signal transduction and protein expression of the peripheral nervous system by mediating intercellular communication. However, the specific role and mechanism of EVs and exosomal-miRNAs in the occurrence and development of DPN in high-glucose environments are not fully understood. This article reviews the promotion of EVs and exosomal-miRNAs in the occurrence and development of DPN in inhibiting axon growth, promoting inflammatory response, and inducing vascular injury in a high glucose environment.

Exploring the boost of steaming with wine on Ligustri Lucidi Fructus in treating postmenopausal osteoporosis based on superior "multi-component structure" and iron/bone metabolism coregulation

BACKGROUND

Clinical studies indicated that postmenopausal osteoporosis (PMOP) often accompanied by iron overload risk factor, which exacerbated bone metabolism disorders and accelerated PMOP. Previous research found that multicomponent in Ligustri Lucidi Fructus (FLL) or wine-steamed FLL (WFLL) acted on the common targets of iron overload and PMOP simultaneously, which indicated that FLL and WFLL probably regulated iron/bone metabolism dually. Additionally, WFLL had more superior effect according to the theory of Chinese medicine for thousands of years.

PURPOSE

To reveal the "superior multi-component structure (SMCS)" and its molecular mechanisms in parallelly down-regulating iron overload and rescuing bone metabolism by WFLL.

DESIGNS AND METHODS

HPLC fingerprinting was established to compare the chemical profiles of FLL and WFLL; Then, the chemical compositions and quality markers of FLL and WFLL were analyzed by UPLC-Orbitrap-MS/MS coupled with OPLS-DA; the dynamic contents of quality markers and the multi-component structure at different wine steaming times (WST) were simultaneously determined by HPLC-DAD. Meanwhile, the dynamic efficacy of FLL at different WST were hunt by systematic zebrafish model. Subsequently, potential mechanism of WFLL in treating PMOP accompanied with iron overload was obtained from network pharmacology (NP) and molecular docking (MD). Finally, zebrafish and ovariectomy rat model were carried out to validate this potential mechanism.

RESULTS

HPLC fingerprints similarity of 15 batches in FLL and WFLL were among 0.9-1.0. 126 compositions were identified, including 58 iridoids, 25 terpenes, 30 phenylethanoids, 7 flavonoids and 6 others. 20 quality markers associated with WFLL was revealed, and the ratio of phenylethanols: Iridoids: Triterpenes (P/I/T) was converted from 1: 15: 4.5 to 1: 0.8: 0.9 during steaming (0 - 24 h) calculated by the quantification of 11 quality markers; the bone mineralization and motor performance of zebrafish larvae indicated that the optimum efficacy of WFLL at 12 h (p < 0.05) in which the SMCS of P/I/T was converted to 1: 4: 1.8. NP discovered that BMP-Smad pathway is one of the potential mechanisms of FLL in anti PMOP and then regulated bone formation and iron overload simultaneously. MD revealed that 17 active ingredients and 10 core targets genes could spontaneously bind with appropriate affinity. Rats model verified that FLL and WFLL significantly reversed PMOP, based on the improvement in bone formation indexes (ALP, OPG, OGN), iron metabolism indicators (hepcidin, ferritin), bone microstructure (BMD, BV/TV, Tb. Th, Tb. N); Moreover, WFLL significant enhanced reversal effect in anti-PMOP compared to FLL (p < 0.05). FLL and WFLL increased genes and proteins expression (Hep, BMP-6, p-Smad1/5, Smad4) related to BMP-Smad pathway compared with model group, and WFLL was more superior than FLL (p< 0.05).

CONCLUSION

The SMCS of FLL was optimized by wine-steam, WFLL represented a dual effect in downregulating iron overload and promoting bone formation, and the BMP-Smad pathway is one of the potential molecular mechanisms.

Positive association between circulating Caveolin-1 and microalbuminuria in overt diabetes mellitus in pregnancy

AIMS

Mounting evidence has shown that caveolin-1 plays a pathological role in the progression of albuminuria. Our study aimed to provide clinical evidence showing whether circulating caveolin-1 levels were associated with microalbuminuria (MAU) in women with overt diabetes mellitus in pregnancy (ODMIP).

METHODS

A total of 150 pregnant women were enrolled in different groups, including 40 women with ODMIP and MAU (ODMIP + MAU), 40 women with ODMIP, and 70 women without ODMIP (Non-ODMIP). Plasma caveolin-1 levels were determined by ELISA. The presence of caveolin-1 in the human umbilical vein vascular wall was evaluated by immunohistochemical and western blot analysis, respectively. Albumin transcytosis across endothelial cells was measured using an established nonradioactive in vitro approach.

RESULTS

Significantly increased levels of plasma caveolin-1 were detected in ODMIP + MAU women. The Pearson's correlation analysis revealed a positive correlation between plasma caveolin-1 levels and Hemoglobin A1c (HbA1c %) as well as with MAU in the ODMIP + MAU group. Simultaneously, experimental knockdown or overexpression of caveolin-1 significantly decreased or increased the level of albumin transcytosis across both human and mouse glomerular endothelial cells (GECs), respectively.

CONCLUSIONS

Our data showed a positive association between plasma caveolin-1 levels and microalbuminuria in ODMIP + MAU.

Reduced angiogenesis and delayed endochondral ossification in CD163-/- mice highlights a role of M2 macrophages during bone fracture repair

While recent studies showed that macrophages are critical for bone fracture healing, and lack of M2 macrophages have been implicated in models of delayed union, functional roles for specific M2 receptors have yet to be defined. Moreover, the M2 scavenger receptor CD163 has been identified as a target to inhibit sepsis following implant-associated osteomyelitis, but potential adverse effects on bone healing during blockage therapy have yet to be explored. Thus, we investigated fracture healing in C57BL/6 versus CD163-/- mice using a well-established closed, stabilized, mid-diaphyseal femur fracture model. While gross fracture healing in CD163-/- mice was similar to that of C57BL/6, plain radiographs revealed persistent fracture gaps in the mutant mice on Day 14, which resolved by Day 21. Consistently, 3D vascular micro-CT demonstrated delayed union on Day 21, with reduced bone volume (74%, 61%, and 49%) and vasculature (40%, 40%, and 18%) compared to C57BL/6 on Days 10, 14, and 21 postfracture, respectively (p < 0.01). Histology confirmed large amounts of persistent cartilage in CD163-/- versus C57BL/6 fracture callus on Days 7 and 10 that resolves over time, and immunohistochemistry demonstrated deficiencies in CD206+ M2 macrophages. Torsion testing of the fractures confirmed the delayed early union in CD163-/- femurs, which display decreased yield torque on Day 21, and a decreased rigidity with a commensurate increase in rotation at yield on Day 28 (p < 0.01). Collectively, these results demonstrate that CD163 is required for normal angiogenesis, callus formation, and bone remodeling during fracture healing, and raise potential concerns about CD163 blockade therapy.

Evidence of bisphosphonate-conjugated sitafloxacin eradication of established methicillin-resistant S. aureus infection with osseointegration in murine models of implant-associated osteomyelitis

Eradication of MRSA osteomyelitis requires elimination of distinct biofilms. To overcome this, we developed bisphosphonate-conjugated sitafloxacin (BCS, BV600072) and hydroxybisphosphonate-conjugate sitafloxacin (HBCS, BV63072), which achieve "target-and-release" drug delivery proximal to the bone infection and have prophylactic efficacy against MRSA static biofilm in vitro and in vivo. Here we evaluated their therapeutic efficacy in a murine 1-stage exchange femoral plate model with bioluminescent MRSA (USA300LAC::lux). Osteomyelitis was confirmed by CFU on the explants and longitudinal bioluminescent imaging (BLI) after debridement and implant exchange surgery on day 7, and mice were randomized into seven groups: 1) Baseline (harvested at day 7, no treatment); 2) HPBP (bisphosphonate control for BCS) + vancomycin; 3) HPHBP (hydroxybisphosphonate control for HBCS) + vancomycin; 4) vancomycin; 5) sitafloxacin; 6) BCS + vancomycin; and 7) HBCS + vancomycin. BLI confirmed infection persisted in all groups except for mice treated with BCS or HBCS + vancomycin. Radiology revealed catastrophic femur fractures in all groups except mice treated with BCS or HBCS + vancomycin, which also displayed decreases in peri-implant bone loss, osteoclast numbers, and biofilm. To confirm this, we assessed the efficacy of vancomycin, sitafloxacin, and HBCS monotherapy in a transtibial implant model. The results showed complete lack of vancomycin efficacy while all mice treated with HBCS had evidence of infection control, and some had evidence of osseous integrated septic implants, suggestive of biofilm eradication. Taken together these studies demonstrate that HBCS adjuvant with standard of care debridement and vancomycin therapy has the potential to eradicate MRSA osteomyelitis.

Transcriptome profiling of intact bowel wall reveals that PDE1A and SEMA3D are possible markers with roles in enteric smooth muscle apoptosis, proliferative disorders, and dysautonomia in Crohn's disease

Background: Inflammatory bowel disease (IBD) is a complex and multifactorial inflammatory condition, comprising Crohn's disease (CD) and ulcerative colitis (UC). While numerous studies have explored the immune response in IBD through transcriptional profiling of the enteric mucosa, the subtle distinctions in the pathogenesis of Crohn's disease and ulcerative colitis remain insufficiently understood. Methods: The intact bowel wall specimens from IBD surgical patients were divided based on their inflammatory status into inflamed Crohn's disease (iCD), inflamed ulcerative colitis (iUC) and non-inflamed (niBD) groups for RNA sequencing. Differential mRNA GO (Gene Ontology), and KEGG (Kyoto Encyclopedia of Genes and Genomes), and GSEA (Gene Set Enrichment Analysis) bioinformatic analyses were performed with a focus on the enteric autonomic nervous system (ANS) and smooth muscle cell (SMC). The transcriptome results were validated by quantitative polymerase chain reaction (qPCR) and immunohistochemistry (IHC). Results: A total of 2099 differentially expressed genes were identified from the comparison between iCD and iUC. Regulation of SMC apoptosis and proliferation were significantly enriched in iCD, but not in iUC. The involved gene PDE1A in iCD was 4-fold and 1.5-fold upregulated at qPCR and IHC compared to that in iUC. Moreover, only iCD was significantly associated with the gene sets of ANS abnormality. The involved gene SEMA3D in iCD was upregulated 8- and 5-fold at qPCR and IHC levels compared to iUC. Conclusion: These findings suggest that PDE1A and SEMA3D may serve as potential markers implicated in enteric smooth muscle apoptosis, proliferative disorders, and dysautonomia specifically in Crohn's disease.

[BCS1Neonatal growth retardation and lactic acidosis initiated by novel mutation sites in L gene]

This study aims to analyze the clinical characteristics and genetic variations of two cases with developmental delay and lactic acidosis in a family, and to explore the relationship between genetic variations and clinical features. A retrospective analysis was conducted on the clinical characteristics of two siblings with developmental delay and lactic acidosis who were treated at the Neonatal Department of Children's Hospital of Chongqing Medical University in May 2019 and December 2021, respectively. Whole-exome sequencing was used to detect genetic variations in the affected children. Homology modeling of the BCS1L protein was performed to analyze the structural and functional changes of the protein. The correlation between genetic variations and clinical phenotypes was analyzed. The results showed that the main clinical features of the two affected children in this family were manifestations of mitochondrial respiratory chain complex Ⅲ deficiency, including prematurity, developmental delay, respiratory failure, lactic acidosis, cholestasis, liver dysfunction, renal tubular lesions, coagulation dysfunction, anemia, hypoglycemia, hypotonia, and early death. Whole-exome sequencing revealed a novel deletion mutation c.486_488delGGA (p.E163del) and a novel missense mutation c.992C>T (p.T331I) in the BCS1L gene. Structural analysis of the homology modeling showed that the compound heterozygous mutation had a significant impact on protein function. In conclusion, the novel mutation site c.992C>T (p.T331I) in the BCS1L gene is a "likely pathogenic" mutation, and the compound heterozygous mutation is closely related to the phenotype of mitochondrial respiratory chain complex Ⅲ deficiency.

Systematic investigation of the material basis, multiple mechanisms and quality control of Simiao Yong'an decoction combined with antibiotic in the treatment of sepsis

BACKGROUND

Sepsis is one of the major threats to human health with high mortality. Simiao Yong'an decoction (SMYAD) has the efficacy of anti-inflammation, improving coagulation and microcirculation, which is applicable for the clinical assistance treatment of sepsis. Yet, its material basis and relevant mechanisms are still vague.

PURPOSE

Explore the quality markers (Q-markers), biomarkers and potential mechanisms of SMYAD combined with imipenem/cilastatin sodium for anti-sepsis.

METHODS

Linear-Trap-LC/MSⁿ was employed to profile the compounds in the extract and medicated serum of SMYAD. Then, the components and targets obtained from databases were applied to network pharmacology. Q-markers' range was narrowed via the affinity of three times docking and determined as per its screening criteria. Also, the content of them was detected by HPLC. Next, cecal ligation and puncture (CLP) model was reproduced to observe the effect of SMYAD united antibiotic by survival rate, histopathology score, ELISA, western blot and qPCR. Finally, metabolomics based upon GC-MS was exerted to discover the differential endogenous metabolites, metabolic pathway and joint pathway of SMYAD combined with antibiotic for sepsis.

RESULTS

The 25 serum migrant ingredients derived from 113 chemical compounds of SMYAD were identified for the first time, and 6 components were determined as the Q-markers of SMYAD. The enrichment analysis indicated that the potential mechanism was mainly associated with the IL-17 signaling pathway, complement-coagulation cascades signaling pathway and VEGF signaling pathway. Then, SMYAD united antibiotic declined the mortality of septic rats, restored cytokine levels, ameliorated histopathological lesions and decreased the mRNA and protein expression of target proteins in a dose-dependent way. Furthermore, 8 differential metabolites were regarded as latent biomarkers related to the antiseptic effect of SMYAD united antibiotic, which were mainly involved in the Citrate cycle (TCA cycle) metabolic pathway.

CONCLUSIONS

Different skeletons of compounds, including iridoids, phenylpropanoids, organic acids, triterpenes and others, were the main compositions of SMYAD. Among them, 6 components were determined as the Q-markers, which provided a basis for the construction of quality standards for this ancient classic formula. The combination therapy of SMYAD and antibiotic obviously ameliorated inflammatory reaction, coagulation dysfunction and microcirculation abnormalities for sepsis by inhibiting IL-17 signaling pathway, complement-coagulation cascades signaling pathway and VEGF signaling pathway.

Evidence of Bisphosphonate-Conjugated Sitafloxacin Eradication of Established Methicillin-Resistant S. aureus Infection with Osseointegration in Murine Models of Implant-Associated Osteomyelitis

Eradication of MRSA osteomyelitis requires elimination of distinct biofilms. To overcome this, we developed bisphosphonate-conjugated sitafloxacin (BCS, BV600072) and hydroxybisphosphonate-conjugate sitafloxacin (HBCS, BV63072), which achieve "target-and-release" drug delivery proximal to the bone infection and have prophylactic efficacy against MRSA static biofilm in vitro and in vivo. Here we evaluated their therapeutic efficacy in a murine 1-stage exchange femoral plate model with bioluminescent MRSA (USA300LAC::lux). Osteomyelitis was confirmed by CFU on the explants and longitudinal bioluminescent imaging (BLI) after debridement and implant exchange surgery on day 7, and mice were randomized into seven groups: 1) Baseline (harvested at day 7, no treatment); 2) HPBP (bisphosphonate control for BCS) + vancomycin; 3) HPHBP (bisphosphonate control for HBCS) + vancomycin; 4) vancomycin; 5) sitafloxacin; 6) BCS + vancomycin; and 7) HBCS + vancomycin. BLI confirmed infection persisted in all groups except for mice treated with BCS or HBCS + vancomycin. Radiology revealed catastrophic femur fractures in all groups except mice treated with BCS or HBCS + vancomycin, which also displayed decreases in peri-implant bone loss, osteoclast numbers, and biofilm. To confirm this, we assessed the efficacy of vancomycin, sitafloxacin, and HBCS monotherapy in a transtibial implant model. The results showed complete lack of vancomycin efficacy, while all mice treated with HBCS had evidence of infection control, and some had evidence of osseous integrated septic implants, suggestive of biofilm eradication. Taken together these studies demonstrate that HBCS adjuvant with standard of care debridement and vancomycin therapy has the potential to eradicate MRSA osteomyelitis.

Preparation and application of sulfated lily polysaccharide bridged polyhedral oligomeric silsesquioxane hybrid organosilicas as stationary phase

Periodic mesoporous organosilicas (PMO) hydrophilic microspheres were synthesized by co-condensation of sulfated polysaccharide from Lilum lancifolium Thunb. bridged silane (SLLTPBS) and polyhedral oligomeric silsesquioxane (POSS) as stationary phase (PMO(SLLTP-POSS)) for per aqueous liquid chromatography (PALC), which would overcome the disadvantages of using a large amount of acetonitrile on the hydrophilic interaction liquid chromatography (HILIC) columns. Average particle size of PMO (SLLTP-POSS) microspheres was 4.9 μm, which was suitable for stationary phase. The retention mechanism of the stationary phase in PALC was mainly hydrophobic interactions and also included some ion-exchange interactions and electrostatic interactions. The acid-base resistance was greatly improved compared to the C18 column. The PMO(SLLTP-POSS) column under PALC mode had increased the resolution when separating some hydrophilic compounds such as eight organic acids and eleven sweeteners compared with the C18 column and HILIC column. The new column was more efficient than the HILIC columns. Additionally, a PALC-triple quadrupole mass spectrometry approach for the simultaneous identification of the eleven sweeteners was developed. The averagere coveries of the eleven compounds were 70.20%-91.33% with the relative standard deviation (RSD) range of 1.74% to 4.27%. The results showed good precision and accuracy of the method.

Day-case loop ileostomy reversal based on the community hospital joined enhanced recovery after surgery (CHJ-ERAS) program in China: Safe and feasible

BACKGROUND

This study was performed to determine the feasibility of Day-case loop ileostomy reversal (DLIR) in China based on the community hospital joined enhanced recovery after surgery (CHJ-ERAS) program.

METHOD

Patients who underwent loop ileostomy were enrolled in the CHJ-ERAS program for DLIR after rigorous evaluation. The primary outcome was the results of short-term follow-ups.

RESULTS

From August 2017 to April 2022, 216 patients have been enrolled in the CHJ-ERAS program for DLIR. After DLIR, 14 patients (14/216, 6.5%) have recorded 17 episodes of postoperative complications within 1 month after surgery, including 10 readmission and 2 reoperation. Compared with in-patient loop ileostomy reversal, DLIR based on CHJ-ERAS did not increase the postoperative complications and reoperations.

CONCLUSION

The CMJ-ERAS program for DLIR in our center is a safe and feasible alternative option for inpatient LIR and an acceptable transitional approach for the development of day-case DLIR in developing countries.

A stochastic exposure model integrating random forest and agent-based approaches: Evaluation for PM2.5 in Jiangsu, China

This research proposes an Activity Pattern embedded Air Pollution Exposure Model (AP2EM), based on survey data of when, where, and how people spend their time and indoor/outdoor ratios for microenvironments. AP2EM integrates random forest and agent-based approaches to simulate the stochastic exposure to outdoor fine particulate matter (PM_2.5) along with indoor and in-vehicle PM_2.5 of outdoor origin. The R² of the linear regression between the model's calculations and personal measurement was 0.65, which was more accurate than the commonly-used aggregated exposure (AE) model and the outdoor exposure (OE) model. The population-weighted PM_2.5 exposure estimated by the AP2EM was 36.7 μg/m³ in Jiangsu, China, during 2014-2017. The OE model overestimated exposure by 54.0%, and the AE model underestimated exposure by 6.5%. These misestimate reflect ignorance of traditional studies on effects posed from time spent indoors (~85%) and doing low respiratory rate activities (~93%), problems of biased sampling, and neglecting low probability events. The proposed AP2EM treats activity patterns of individuals as chains and uses stochastic estimates to model activity choices, providing a more comprehensive understanding of human activity and exposure characteristics. Overall, the AP2EM is applicable for other air pollutants in different regions and benefits China's air pollution control policy designs.

Average SAR prediction, validation, and evaluation for a compact MR scanner head-sized RF coil

A recently developed compact 3 T (C3T) MRI scanner with high performance gradients [1, 2] has a dedicated radiofrequency (RF) transmit coil that exposes only the head, neck and a small portion of the upper body region during head-first scanning. Due to the unique coil geometry and patient positioning, the established SAR model used for a conventional whole-body scanner cannot be directly translated to the C3T. Here a specific absorption rate (SAR) estimation and validation framework was developed and used to implement a dedicated and accurate SAR prediction model for the C3T. Two different SAR prediction models for the C3T were defined and evaluated: one based on an anatomically derived exposed mass, and one using a fixed anatomical position located caudally to the RF coil to determine the exposed mass. After coil modeling and virtual human body simulation, the designed SAR prediction model was implemented on the C3T and verified with calorimetry and in vivo scan power monitoring. The fixed-demarcation exposed mass model was selected as appropriate exposed mass region to accurately estimate the SAR deposition in the patient on the C3T.

Psychometric properties of the metacognitions about smartphone use questionnaire (MSUQ) in Chinese college students

AIMS

Over the last ten years, several studies investigating the role of metacognitions in addictive behaviors, including technological addictions, have been published. Problematic Smartphone use has been conceptualized as a behavioural addiction and a psychometrically sound self-report measure to assess metacognitions about PSU has been recently published. The objective of this study was to evaluate some psychometric properties (e.g., factor structure, reliability, and validity) of the Chinese Metacognitions about Smartphone Use Questionnaire (Chinese MSUQ).

METHODS

A sample of 698 undergraduates (F = 54.70%, mean age = 19.89 ± 1.38 years) were enrolled in China. An exploratory factor analysis was first performed in a randomly allocated subsample of 349 participants. A confirmatory factor analysis was then computed on a second subsample of 349 participants to test its fitting with the identified factor structure. Internal consistency and predictive validity were verified.

RESULTS

The result of exploratory factor analysis showed a 2-factor structure, which consists of positive metacognitions concerning emotional and cognitive regulation and social advantages of smartphone use (MSUQ-PM) and negative metacognitions about uncontrollability and cognitive harm of smartphone use (MSUQ-NM). The confirmatory factor analysis indicated that the 2-factor structure of Chinese MSUQ had appropriate fit. Cronbach's Alphas ranged from 0.90 to 0.92. Additionally, regression analysis showed that MSUQ-PM and MSUQ-NM positively predicted PSU. Notably, MSUQ-NM is a stronger predictor of PSU compared with MSUQ-PM, with a rescaled importance of 86.36%.

CONCLUSIONS

The Chinese MSUQ has appropriate psychometric properties, suggesting it is a reliable instrument to assess metacognitions about smartphone use in the Chinese context.