BACKGROUND:Pediatric flexible flatfoot is a common foot deformity that often leads to foot pain and reduced quality of life.OBJECTIVE:To explore the relationship between radiographic parameters and clinical efficacy of subtalar arthroereisis in the treatment of pediatric flexible flatfoot.METHODS:A retrospective study was conducted on 56 pediatric patients(mean age of 11.8 years)who underwent subtalar arthroereisis at Guangzhou Orthopedic Hospital between January 2022 and May 2023.All patients underwent detailed radiographic examinations and clinical evaluations before and after surgery,including the American Orthopaedic Foot & Ankle Society Ankle-Hindfoot score and Visual Analog Scale score.Paired t-tests and independent t-tests were used to compare changes in radiographic parameters and clinical scores before and after surgery.Correlation analyses were conducted to evaluate the relationship between radiographic parameters and clinical outcomes.RESULTS AND CONCLUSION:(1)All radiographic parameters significantly improved during the 8 to 12-month follow-up after surgery(P＜0.001).(2)Clinical evaluation results indicated that the American Orthopaedic Foot & Ankle Society Ankle-Hindfoot score significantly improved from 66.2±6.0 preoperatively to 91.3±5.8 postoperatively,and the Visual Analog Scale score significantly decreased from 3.1±0.8 preoperatively to 1.3±0.8 postoperatively(P＜0.001).(3)Independent t-tests showed a significant difference in postoperative the first metatarsal angle and Visual Analog Scale score grades(P=0.043),with a smaller the first metatarsal angle associated with less postoperative pain;preoperative lateral arch angle showed a significant difference between the"excellent"and"good"groups in postoperative American Orthopaedic Foot & Ankle Society Ankle-Hindfoot scores(P=0.033),suggesting that a smaller preoperative posterior arch angle might predict better postoperative foot function recovery.(4)Correlation analysis showed that preoperative posterior arch angle(r=-0.486,P＜0.01)and heel pitch angle(r=-0.344,P＜0.01)were significantly negatively correlated with postoperative American Orthopaedic Foot & Ankle Society Ankle-Hindfoot,while preoperative medial longitudinal arch angle(r=0.293,P＜0.05)was significantly positively correlated with postoperative American Orthopaedic Foot & Ankle Society Ankle-Hindfoot.Postoperative medial longitudinal arch angle(r=0.331,P＜0.05)and lateral arch angle(r=0.387,P＜0.01)were significantly positively correlated with postoperative American Orthopaedic Foot & Ankle Society Ankle-Hindfoot,whereas postoperative Bohler's angle(r=-0.272,P＜0.05),posterior arch angle(r=-0.461,P＜0.01),and heel pitch angle(r=-0.318,P＜0.01)were significantly negatively correlated with postoperative American Orthopaedic Foot & Ankle Society Ankle-Hindfoot.(5)It is concluded that subtalar arthroereisis is significantly effective in correcting pediatric flexible flatfoot,and improvements in radiographic parameters are closely related to clinical efficacy.Preoperative and postoperative radiographic evaluations can serve as important reference indicators for predicting postoperative clinical outcomes,guiding clinicians to optimize treatment plansand rehabilitation programs.

BACKGROUND:Pediatric flexible flatfoot is a common foot deformity that often leads to foot pain and reduced quality of life.OBJECTIVE:To explore the relationship between radiographic parameters and clinical efficacy of subtalar arthroereisis in the treatment of pediatric flexible flatfoot.METHODS:A retrospective study was conducted on 56 pediatric patients(mean age of 11.8 years)who underwent subtalar arthroereisis at Guangzhou Orthopedic Hospital between January 2022 and May 2023.All patients underwent detailed radiographic examinations and clinical evaluations before and after surgery,including the American Orthopaedic Foot & Ankle Society Ankle-Hindfoot score and Visual Analog Scale score.Paired t-tests and independent t-tests were used to compare changes in radiographic parameters and clinical scores before and after surgery.Correlation analyses were conducted to evaluate the relationship between radiographic parameters and clinical outcomes.RESULTS AND CONCLUSION:(1)All radiographic parameters significantly improved during the 8 to 12-month follow-up after surgery(P＜0.001).(2)Clinical evaluation results indicated that the American Orthopaedic Foot & Ankle Society Ankle-Hindfoot score significantly improved from 66.2±6.0 preoperatively to 91.3±5.8 postoperatively,and the Visual Analog Scale score significantly decreased from 3.1±0.8 preoperatively to 1.3±0.8 postoperatively(P＜0.001).(3)Independent t-tests showed a significant difference in postoperative the first metatarsal angle and Visual Analog Scale score grades(P=0.043),with a smaller the first metatarsal angle associated with less postoperative pain;preoperative lateral arch angle showed a significant difference between the"excellent"and"good"groups in postoperative American Orthopaedic Foot & Ankle Society Ankle-Hindfoot scores(P=0.033),suggesting that a smaller preoperative posterior arch angle might predict better postoperative foot function recovery.(4)Correlation analysis showed that preoperative posterior arch angle(r=-0.486,P＜0.01)and heel pitch angle(r=-0.344,P＜0.01)were significantly negatively correlated with postoperative American Orthopaedic Foot & Ankle Society Ankle-Hindfoot,while preoperative medial longitudinal arch angle(r=0.293,P＜0.05)was significantly positively correlated with postoperative American Orthopaedic Foot & Ankle Society Ankle-Hindfoot.Postoperative medial longitudinal arch angle(r=0.331,P＜0.05)and lateral arch angle(r=0.387,P＜0.01)were significantly positively correlated with postoperative American Orthopaedic Foot & Ankle Society Ankle-Hindfoot,whereas postoperative Bohler's angle(r=-0.272,P＜0.05),posterior arch angle(r=-0.461,P＜0.01),and heel pitch angle(r=-0.318,P＜0.01)were significantly negatively correlated with postoperative American Orthopaedic Foot & Ankle Society Ankle-Hindfoot.(5)It is concluded that subtalar arthroereisis is significantly effective in correcting pediatric flexible flatfoot,and improvements in radiographic parameters are closely related to clinical efficacy.Preoperative and postoperative radiographic evaluations can serve as important reference indicators for predicting postoperative clinical outcomes,guiding clinicians to optimize treatment plansand rehabilitation programs.

Objective:To investigate the application value of photon-counting detector CT (PCD-CT) in preoperative identification of critical anatomical structures and surgical assessment in pancreatic cancer, and to compare its performance with conventional energy-integrating detector CT (EID-CT) in delineating tumor margins, vascular structures, and neural anatomy.Methods:This single-center retrospective matched case-control study included 25 patients with pathologically confirmed pancreatic ductal adenocarcinoma who underwent PCD-CT enhanced scanning and curative surgery at Peking Union Medical College Hospital between February and June 2025 (PCD-CT group). These patients were matched in a 1∶2 ratio to 50 patients who underwent EID-CT between January 2016 and December 2024 and subsequently received curative surgery (EID-CT group). Tumor boundary clarity, vascular visualization scores, and neural structure visibility were subjectively evaluated using the Likert scoring system. The assessed vessels included the celiac artery, common hepatic artery, superior mesenteric artery, splenic artery, portal vein, superior mesenteric vein, splenic vein, and pancreaticoduodenal arterial arcade. Imaging-based assessment of structural involvement was compared with intraoperative findings and pathological results to calculate diagnostic accuracy. Surgeons rated the usefulness of PCD-CT images for identifying key structures and determining resectability using a 5-point Likert scale. The Mann-Whitney U test was used for group comparisons of subjective scores, and categorical data were analyzed using the χ2 test or Fisher exact test. Results:The PCD-CT group showed significantly higher scores for tumor boundary clarity, vascular visualization, and neural structure detectability than those of the EID-CT group (all P<0.05). The accuracy of assessing superior mesenteric vein involvement was 96.0% (24/25) in the PCD-CT group and 72.0% (36/50) in the EID-CT group, with a significant difference ( χ2=6.00, P=0.014). Postoperative surgeon evaluations indicated that PCD-CT provided substantial assistance for both key structure identification [5 (5, 5)] and resectability assessment [5 (4, 5)]. Conclusion:PCD-CT demonstrates superior performance over EID-CT in preoperative delineation of tumor margins, vascular structures, and neural anatomy and in the assessment of structural involvement in pancreatic cancer. It provides valuable anatomical information to support preoperative evaluation and surgical decision-making.

Objective To develop a novel protective ventilator circuit component and to verify its performance by water seal and anti-splash experiments.Methods A novel protective ventilator circuit component had a design scheme with the multifunctional joint,and consisted of a tee connection tube,an isolation sleeve and a stop sleeve,of which,the tee connection tube was made of polyethylene polymer material and the others were made of silicone material.The tee connection tube had a T-shaped structure with two standard connection ports,which was composed of an adapter,a sealing cap,a plug and a sealing ring;the isolation sleeve was in the shape of a cylinder with a raised bottom,which was inserted into the adapter;the stop sleeve was located in the isolation sleeve,with an inverted frustum of a cone at the bottom and a rounded hole in the middle of the inverted frustum.An open ventilator circuit tube was involved in the performance verification of the circuit component developed.In the water seal experiment,sputum aspiration was simulated and the heights of the liquid level drop in the L-shaped tubes were compared after sputum aspiration.In the anti-splash experiment,the infection rates on the surfaces of the sterile hole towels and gloves were calculated.Results Water seal experiment showed after sputum aspiration the open ventilator circuit tube had the liquid level at the L-shaped tube higher significantly than that of the circuit component;the anti-splash experiment indicated sputum aspiration resulted in the occurance of the splashing out of the secretion and 77.5%infection rate by the open ventilator circuit tube,while no splashing out and 0%infection rate by the circuit component developed.Conclusion The novel protective ventilator circuit component behaves well in sealing and anti-splashing,and thus is worthy of clinical application for sputum aspiration.[Chinese Medical Equipment Journal,2025,46(4):113-117]

BACKGROUND:Iron overload is an independent factor inducing osteoporosis,but the action mechanism is currently unclear.Therefore,exploring the effects of iron overload on osteoblast-related cells will help to deeply understand the pathogenesis of osteoporosis and provide potential strategies for osteoporosis treatment.OBJECTIVE:To explore the effects of iron overload environment on osteoblast precursor cell activity,ferroptosis,and osteogenic differentiation.METHODS:Osteoblast precursor cells(MC3T3-E1 cells)were divided into blank group,iron overload group,fer-1 group,and deferoxamine group.The iron overload group was treated with 300 μmol/L ammonium ferric citrate in the culture medium for 48 hours to simulate the iron overload microenvironment.The cells in fer-1 group and deferoxamine group were pretreated with 5 μmol/L antioxidant fer-1 and 5 μmol/L deferoxamine for 8 hours,respectively,and then added with 300 μmol/L ammonium ferric citrate for 48 hours.CCK-8 assay was used to determine the cell viability.Intracellular reactive oxygen species levels were detected employing a reactive oxygen species fluorescent probe.Changes in mitochondrial membrane potential were monitored with a mitochondrial membrane potential fluorescent probe.Mitochondrial morphology was observed employing transmission electron microscopy.Cellular glutathione levels were measured with a reduced glutathione colorimetric assay kit.Lipid peroxidation levels were assessed with a malondialdehyde colorimetric assay kit.Cellular ferrous ion levels were determined with a ferrous ion colorimetric assay kit.The osteogenic and mineralization capabilities of the cells were verified by alkaline phosphatase staining and alizarin red staining.Collagen secretion ability was detected using Sirius Red staining.The expression of osteogenic/ferroptosis-related genes and proteins was examined through reverse transcription quantitative polymerase chain reaction and western blot analysis.RESULTS AND CONCLUSION:(1)In an iron-overload environment,the mitochondrial membrane potential of cells decreased and their structure was compromised,with an elevation in intracellular lipid peroxidation levels and a downregulation of genes and proteins associated with ferroptosis resistance.However,pretreatment with fer-1 and deferoxamine led to an increase in mitochondrial membrane potential and partial restoration of morphology,a reduction in intracellular lipid peroxidation levels,and an upregulation of genes and proteins related to ferroptosis resistance.(2)In an iron-overload environment,the levels of cellular alkaline phosphatase,the formation of mineralized nodules,and the synthesis of collagen fibers were all found to be decreased.Pretreatment with fer-1 and deferoxamine was observed to upregulate the expression of osteogenic differentiation in cells.(3)In summary,iron overload could increase intracellular oxidative stress levels,mediate ferroptosis in MC3T3-E1 cells and inhibit osteogenic differentiation,thereby inducing osteoporosis.Therefore,maintaining iron homeostasis and inhibiting osteogenesis-related ferroptosis may be potential strategies to prevent or treat osteoporosis.

Objective:To investigate the effect of PD-1/PD-L1 inhibitor BMS-1 on LPS-induced inflammation in mouse microg-lia cells(BV-2 cells).Methods:Bv-2 cells were divided into Control group,LPS group and LPS+BMS-1 group.Bv-2 cells in Control group were cultured in DMEM medium for 78 hours,cells in LPS group were stimulated with 100 ng/ml LPS for 6 hours after 72 hours of normal culture,Bv-2 cells in LPS+BMS-1 group were treated with 50 nmol/ml BMS-1 for 72 hours and then stimulated with 100 ng/ml LPS for 6 hours.Expressions of PD-1 and iNOS mRNA in each group were detected by RT-qPCR,and expressions of PD-1 and iNOS protein in microglia were detected by Western blot.Flow cytometry was used to detect cell apoptosis in each group.Levels of inflamma-tory cytokines IL-1β,IL-6,TNF-α and IL-10 were detected by ELISA.Results:RT-qPCR and Western blot results showed that com-pared with Control group,LPS group had significantly increased expression of PD-1 and iNOS(P<0.05).Compared with LPS group,LPS+BMS-1 group had significantly decreased expression of PD-1(P<0.05)and significantly increased expression of iNOS(P<0.05).Flow cytometry showed that compared with Control group,LPS group had a significantly increased in apoptosis of microglia(P<0.000 1).Compared with LPS group,LPS+BMS-1 group had a significantly increased in apoptosis of microglia(P<0.000 1).ELISA results showed that compared with Control group,LPS group had no significantly increased in pro-inflammatory factors IL-1β and IL-6(P>0.05),while significantly increased in TNF-α(P<0.000 1)and anti-inflammatory factor IL-10(P<0.000 1).Pro-inflammatory cyto-kine IL-1β in LPS+BMS-1 group was significantly higher than that in LPS group(P=0.000 1),IL-6 and TNF-α were also significantly higher than those in LPS group(P<0.000 1),while anti-inflammatory cytokine IL-10 in LPS+BMS-1 group was significantly lower than that in LPS group(P<0.000 1).Conclusion:BMS-1 can promote LPS-induced inflammatory response or impede the recovery of inflammation,and increase apoptosis of microglia.PD-1/PD-L1 pathway may be a potential therapeutic target for neuroinflammation.

Aim To observe the interventional effects of Polygala fallax Hemsl.(PFH)on diabetic kidney disease(DKD)rats and the regulatory mechanism of ferroptosis.Methods Thirty-six SD rats were ran-domly divided into the control group,DKD group,fer-rostatin-1(Fer-1)group,PFH-L group,PFH-M group,and PFH-H group,with six rats in each group.Model-ing was induced by a one-time intraperitoneal injection of 35 mg·kg-1 streptozocin(STZ)in combination with high-sugar and high-fat feed.Ferrostatin-1(25μmol·kg-1)was injected intraperitoneally in Fer-1 group.The PFH-L,PFH-M,and PFH-H groups were gavaged with 50,100 and 200 mg·kg-1 of alcoholic extracts of PFH respectively,and the control and DKD groups were gavaged with an equal volume of distilled water once a day for eight weeks.At the end of drug administration,blood glucose,24h-UP,BUN and Scr levels were measured in each group of rats.HE stai-ning and Masson staining were used to observe renal histopathological changes.ELISA was employed to de-termine the levels of total iron,MDA and GSH activity.IHC was used to observe the expression of Nrf2,SLC7A11,and GPX4 in renal tissues.Western blot was used to detect the protein expression of COL1A1,α-SMA,TGF-,FTH-1,TFR-1,Nrf2,SLC7A1 1,GPX4,in renal tissues.RT-qPCR was used to detect the ex-pression levels of Nrf2,SLC7A11,GPX4 mRNA in re-nal tissues.Results Compared with the control group,blood glucose,24h-UP,BUN,Scr increased(P＜0.05);glomerular volume increased,tubular dilata-tion and collagen fiber deposition were obvious;total i-ron,MDA content increased and GSH activity de-creased(P＜0.05);there was increased protein ex-pression of COL1A1,α-SMA,TGF-β,TFR-1 and de-creased protein expression of FTH-1(P＜0.01);there was decreased mRNA and protein expression of Nrf2,SLC7A11,GPX4 in DKD group rats(P＜0.01).Compared with the DKD group,blood glucose,24h-UP,BUN and Scr decreased(P＜0.05);renal tissue le-sions were significantly reduced;total iron and MDA content decreased,and GSH activity increased(P＜0.05);COL1A1,α-SMA,TGF-β,and TFR-1 protein expression decreased and FTH-1 protein expression in-creased(P＜0.05,P＜0.01);Nrf2,SLC7A11,GPX4 mRNA and protein expression increased in Fer-1 and PFH dose groups(P＜0.05,P＜0.01).Conclusions PFH attenuates renal histopathological injury in DKD rats,and the mechanism may be related to the regula-tion of the Nrf2/SLC7A11/GPX4 signaling pathway.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

BACKGROUND:Iron overload is an independent factor inducing osteoporosis,but the action mechanism is currently unclear.Therefore,exploring the effects of iron overload on osteoblast-related cells will help to deeply understand the pathogenesis of osteoporosis and provide potential strategies for osteoporosis treatment.OBJECTIVE:To explore the effects of iron overload environment on osteoblast precursor cell activity,ferroptosis,and osteogenic differentiation.METHODS:Osteoblast precursor cells(MC3T3-E1 cells)were divided into blank group,iron overload group,fer-1 group,and deferoxamine group.The iron overload group was treated with 300 μmol/L ammonium ferric citrate in the culture medium for 48 hours to simulate the iron overload microenvironment.The cells in fer-1 group and deferoxamine group were pretreated with 5 μmol/L antioxidant fer-1 and 5 μmol/L deferoxamine for 8 hours,respectively,and then added with 300 μmol/L ammonium ferric citrate for 48 hours.CCK-8 assay was used to determine the cell viability.Intracellular reactive oxygen species levels were detected employing a reactive oxygen species fluorescent probe.Changes in mitochondrial membrane potential were monitored with a mitochondrial membrane potential fluorescent probe.Mitochondrial morphology was observed employing transmission electron microscopy.Cellular glutathione levels were measured with a reduced glutathione colorimetric assay kit.Lipid peroxidation levels were assessed with a malondialdehyde colorimetric assay kit.Cellular ferrous ion levels were determined with a ferrous ion colorimetric assay kit.The osteogenic and mineralization capabilities of the cells were verified by alkaline phosphatase staining and alizarin red staining.Collagen secretion ability was detected using Sirius Red staining.The expression of osteogenic/ferroptosis-related genes and proteins was examined through reverse transcription quantitative polymerase chain reaction and western blot analysis.RESULTS AND CONCLUSION:(1)In an iron-overload environment,the mitochondrial membrane potential of cells decreased and their structure was compromised,with an elevation in intracellular lipid peroxidation levels and a downregulation of genes and proteins associated with ferroptosis resistance.However,pretreatment with fer-1 and deferoxamine led to an increase in mitochondrial membrane potential and partial restoration of morphology,a reduction in intracellular lipid peroxidation levels,and an upregulation of genes and proteins related to ferroptosis resistance.(2)In an iron-overload environment,the levels of cellular alkaline phosphatase,the formation of mineralized nodules,and the synthesis of collagen fibers were all found to be decreased.Pretreatment with fer-1 and deferoxamine was observed to upregulate the expression of osteogenic differentiation in cells.(3)In summary,iron overload could increase intracellular oxidative stress levels,mediate ferroptosis in MC3T3-E1 cells and inhibit osteogenic differentiation,thereby inducing osteoporosis.Therefore,maintaining iron homeostasis and inhibiting osteogenesis-related ferroptosis may be potential strategies to prevent or treat osteoporosis.