[Pollution Characteristics and Source Apportionment of VOCs in Urban Areas of Shijiazhuang in Spring].

Samples of ambient volatile organic compounds （VOCs） were collected using SUMMA canisters at three Country Control Sites in Shijiazhuang during the spring of 2019, 2021, and 2022, which were detected using gas chromatography/mass spectrometry （GC/MS）. To investigate the characteristics and temporal variations of VOCs mass concentration levels, the online monitoring data of ozone （O3） and PM2.5 at the same site were also collected. Subsequently, the ozone formation potential （OFP） and secondary organic aerosol formation potential （SOAFP） were utilized to assess the chemical activity of VOCs. Additionally, the potential source areas of VOCs in spring in Shijiazhuang were further identified using the potential source contribution factor （PSCF） method and concentration weight trajectory analysis （CWT）. Hence, the major VOCs sources were evaluated with the VOCs initial mixing ratio. The results demonstrated that the averaged concentration of VOCs during the polluted period and clean period of spring in Shijiazhuang were 191.17 µg·m-3 and 122.18 µg·m-3, respectively. Meanwhile, the OFP was 361.23 µg·m-3 during the polluted period and 266.96 µg·m-3 during the clean period, whereas the SOAFP was 1.98 µg·m-3 and 1.61 µg·m-3, respectively. Therefore, effective control of benzene, toluene, ethylbenzene, and xylene （BTEX） is crucial for reducing PM2.5 and O3 pollution. Based on the results obtained from weight PSCF and CWT, the potential source areas of VOCs were further identified to be primarily located in the eastern Yuhua District, the high-tech district, and the northern Luancheng District of Shijiazhuang. These areas were influenced not only by local emissions but also by transport from neighboring regions, in which consistency between the CWT and PSCF results further supported these findings. Furthermore, the results obtained from the benzene/toluene/ethylbenzene （B/T/E） and xylene/benzene （X/B） ratios indicated that the main sources of VOCs in Shijiazhuang in spring were vehicle exhaust sources and burning sources, leading to a more serious air mass aging phenomenon. Hence, controlling vehicle emissions and implementing regional cooperative measures are the effective strategies for optimizing the air quality of Shijiazhuang.

Copper Vacancy and LSPR-Activated MXene Synergistically Enabling Selective Photoreduction CO2 to Acetate.

Photocatalytic CO2 conversion towards C2+ fuels is a promising technology for simultaneously achieving carbon neutrality and alleviating the energy crisis. However, this strategy is inefficient due to the difficulty of both multi-electron transfer and C-C coupling during C2+ formation. In this work, CuInS2/MXene heterostructure with Cu vacancy is rationally designed by in situ hydrothermal synthesis. The VCu-CuInS2/MXene heterostructure has a suitable band structure and tight interface contact. Catalytic performances under different testing conditions, in situ spectroscopy, and COMSOL simulation reveal that LSPR-activated MXene promotes the formation of crucial intermediate CH2* and triggers the C-C coupling process under near-infrared light, as the key to acetate. Moreover, in situ XPS analysis, DFT calculations, and photoelectrochemical characterizations unveil that copper vacancy can promote charge transfer from CuInS2 to MXene and boost local electron aggregation on the MXene, further enhancing the photocatalytic efficiency and selectivity of C2 products. Contributing to the synergistic effect of copper vacancy and plasmonic MXene, VCu-CuInS2/MXene achieved excellent CO2RR activity with an acetate evolution rate of 250.0 µmol/h/g and a selectivity of 97.5 % under the full spectrum irradiation, which is 38.8 and 3.3 times higher than that of VCu-CuInS2 and CuInS2/MXene, respectively.

Harnessing Stem Cell-Derived Extracellular Vesicles for the Regeneration of Degenerative Bone Conditions.

Degenerative bone disorders such as intervertebral disc degeneration (IVDD), osteoarthritis (OA), and osteoporosis (OP) pose significant health challenges for aging populations and lack effective treatment options. The field of regenerative medicine holds promise in addressing these disorders, with a focus on utilizing extracellular vesicles (EVs) derived from stem cells as an innovative therapeutic approach. EVs have shown great potential in stimulating biological responses, making them an attractive candidate for rejuvenating degenerative bone disorders. However, a comprehensive review summarizing the current state of this field and providing a clear assessment of EV-based therapies in degenerative bone disorders is currently deficient. In this review, we aim to fill the existing gap by outlining the current knowledge on the role of EVs derived from different types of stem cells, such as mesenchymal stem cells, embryonic stem cells, and induced pluripotent stem cells, in bone regeneration. Furthermore, we discuss the therapeutic potential of EV-based treatments for IVDD, OA, and OP. By substantiating the use of stem cell-derived EVs, we highlight their promising potential as a cell-free strategy to improve degenerative bone disorders.

Influence of Rib Cage on Static Characteristics of Scoliotic Spine.

BACKGROUND: Scoliosis is a three-dimensional (3D) deformity of the spine, which affects the patient's appearance and may lead to abnormal heart and lung function. The rib cage is a structure composed of ribs, sternum, and costal cartilage, which plays a vital role in stabilising the thoracolumbar spine. This study investigates the influence of the rib cage on the static characteristics of the scoliotic spine. METHODS: Two types of 3D finite element (FE) models with or without rib cage (from T1 to S) were established and analysed based on computed tomography (CT) images, to determine the effects of the rib cage on the static characteristics of the scoliotic spine. The FE software, ABAQUS, was used to analyse the static behaviours of scoliotic spine models under a range of loading conditions, including left side bending, right side bending, front tilt, rear supine, and vertical compression. The changes in the von Mises stress (VMS) within the intervertebral discs of spine models with or without rib cage were studied and compared. RESULTS: After including the rib cage, the maximum VMS at the stress concentrations of the normal and scoliotic spine effectively reduced. The VMS in normal intervertebral discs was gentler than that of scoliotic ones. However, the scoliotic spine was more likely to produce large stress concentration in the intervertebral discs of scoliotic segments. CONCLUSIONS: Under the common postures, intervertebral discs of scoliotic segments are more susceptible to generate stress concentrations compared with the normal spine. The rib cage could effectively keep the intervertebral discs of scoliotic segments from further injuries. These results are of great significance for the prevention and treatment of the scoliotic spine.

The influence of the rib cage on the static and dynamic stability responses of the scoliotic spine.

The thoracic cage plays an important role in maintaining the stability of the thoracolumbar spine. In this study, the influence of a rib cage on static and dynamic responses in normal and scoliotic spines was investigated. Four spinal finite element (FE) models (T1-S), representing a normal spine with rib cage (N1), normal spine without rib cage (N2), a scoliotic spine with rib cage (S1) and a scoliotic spine without rib cage (S2), were established based on computed tomography (CT) images, and static, modal, and steady-state analyses were conducted. In S2, the Von Mises stress (VMS) was clearly decreased compared to S1 for four bending loadings. N2 and N1 showed a similar VMS to each other, and there was a significant increase in axial compression in N2 and S2 compared to N1 and S1, respectively. The U magnitude values of N2 and S2 were higher than in N1 and S1 for five loadings, respectively. The resonant frequencies of N2 and S2 were lower than those in N1 and S1, respectively. In steady-state analysis, maximum amplitudes of vibration for N2 and S2 were significantly larger than N1 and S1, respectively. This study has revealed that the rib cage improves spinal stability in vibrating environments and contributes to stability in scoliotic spines under static and dynamic loadings.

[The effect of rib cage on the dynamic response stability of the scoliotic spine].

The purpose of this study is to reveal the protective effect of rib cage on scoliotic spine by comparing the different effect of rib cage on the stability of normal spine and Lenke1 scoliotic spine. Firstly, according to X-ray computed tomography (CT) image data, four spinal finite element models (SFEMs), including normal spine without rib cage (N1), normal spine with normal rib cage (N2), scoliotic spine without rib cage (S1) and scoliotic spine with deformed rib cage (S2), from the first thoracic vertebrae to the sacral vertebrae (T1～S) were established. Secondly, the natural vibration characteristics of the four SFEMs were obtained by modal analysis. Finally, the maximum vibration amplitudes of the four SFEMs under external excitation were obtained by steady-state analysis. As shown in results, compared with N1, the maximum deformation of N2 segment T4～T6 in the X -axis (coronal axis), Y -axis (sagittal axis) and Z -axis (vertical axis) directions decreases by 38.44%, 53.80% and 33.72%, respectively. Compared with S1, the maximum deformation of S2 segment T4～T6 in the X -axis direction, Y -axis direction and Z -axis directions decreases by 44.26%, increases by 32.80% and decreases by 49.23%, respectively. As it can be seen, for normal spine, the rib cage can improve the stability of the whole spine in three directions; for the Lenke1 scoliotic spine, the rib cage can reduce the vibration of the scoliotic spine in the X -axis and Z -axis directions and improves the stability of the whole spine in the two directions, while in the Y -axis direction, for the serious severe anteversion of scoliotic spine, the deformed rib cage exacerbates the vibration of the scoliotic spine in this direction and destroys the stability of the scoliotic spine in the Y -axis direction. This study reveals the biomechanical characteristics of rib caged influence on the stability of the scoliotic spine and it has guiding significance for the study of daily protection methods and protective tools for scoliotic patients.

Differential response to vibration of three forms of scoliosis during axial cyclic loading: a finite element study.

BACKGROUND: Scoliosis is a serious disease that can affect all segments of society. Few studies have investigated the response to vibration of differing sinusoidal axial cyclic loading frequencies for different forms of scoliosis in the lumbar spine. METHODS: In this study, four finite element models, comprising a healthy spine, Lenke-A, Lenke-B and Lenke-C scoliosis of the lumbar S1-L1 region were developed. Modal analysis extracted resonant frequencies of the FE models with an upper body mass of 40 kg and 400 N preload. A transient dynamic analysis was performed to obtain the response to vibration of models under a sinusoidal axial loading of ± 40N at frequencies of 3, 5, 7, 9, 11 and 13 Hz using an upper body mass of 40 kg and 400 N preload. RESULTS: The first-order resonant frequencies of healthy, Lenke-A, Lenke-B and Lenke-C spines were 9.2, 3.9, 4.6 and 5.7 Hz, respectively. A Lenke-A lumbar spine was more likely to deform at a lower vibration frequency and Lenke-C deformed more easily at a higher vibration frequency. Furthermore, the vibration amplitude in the Y-direction (left-right) was greatest and least in the Z-direction (top-bottom). The frequency of cyclic loading closest to the resonant frequency resulted in a maximum value of peak-to-peak vibrational displacement. Furthermore, the vibrational amplitudes in patients with scoliosis were larger than they were in healthy subjects. In addition, axial displacement of the vertebrae in the healthy spine changed steadily whereas fluctuations in the scoliotic vertebrae in scoliosis patients were greater than that of other vertebrae. CONCLUSIONS: Different forms of scoliosis may have different vibrational characteristics, the scoliotic vertebrae being the weak link in scoliosis under loading condition of whole body vibration. Scoliosis was more sensitive to this form of vibration. Where the frequency of axial cyclic vibrational loading of the lumbar spine was closer to its resonant frequency, the vibrational amplitude was larger. These results suggest that vibration will exacerbate the degree of scoliosis and so such patients should reduce their exposure to vibration. Clinical treatment should pay attention to the scoliotic vertebrae and reduce their vibration. These findings may assist in the clinical prevention and treatment of scoliosis.

[The value of ultrasound in diagnosis of IgG4-related sialadenitis].

PURPOSE: To study the ultrasonic manifestation of IgG4-related sialadenitis, and improve sonographers' understanding of this disease. METHODS: Based on the clinical serological test and histopathologic diagnosis, the features were evaluated by sonography in 25 cases of IgG4-related sialadenitis, including the shape and border of the gland, internal echo texture, presence and distribution of vascularity, duct dilatation, presence/absence of calculi and submandibular lymph nodes. The changes on ultrasonography in 14 patients with IgG4-related sialadenitis before and after steroid treatment were evaluated. RESULTS: There were 20 men and 5 women ranging between 42-89 years old with an average age of 64.5 years old. The sites of involvement were submandibular gland (20 cases) and parotid gland (5 cases). Of the 10 patients with diffuse involvement, the lesions showed bilateral symmetrical distribution in 9 patients and unilateral involvement in 1 patient with multiple hypoechoic lesions against a heterogeneous background. The ducts were dilated in 3 patients, and had calculus in 2 patients. Doppler sonography in all patients with diffuse involvement of the gland showed prominent intraglandular vessels. Of the 15 patients with focal involvement, 14 patients showed unilateral involvement and only one showed bilateral involvement of the submandibular gland with hypoechoic heterogeneous. The vessels showed a radial pattern within the lesions. There were definite submandibular lymph nodes involvement by IgG4-related disease in 4 of the 8 patients. After steroid treatment, the prominent sonographic feature of IgG4-related sialadenitis gradually receded. CONCLUSIONS: Sonologist must be aware of sonographic appearances in patients with IgG4-related sialadenitis, which can help correct diagnosis and treatment.

[The value of age-adjusted D-dimer cut-off value in diagnosing deep vein thrombosis in elderly patients].

OBJECTIVE: To validate the value of age-adjusted D-dimer combined with clinical probability to confirm or exclude deep vein thrombosis (DVT) in elderly patients. METHOD: Elderly patients ( ≥ 65 years) suspected with DVT were evaluated by Wells score and D-dimer test. All patients underwent ultrasonography examination except for patients with Wells score < 2 and negative D-dimer test results. Conventional cut-off value is 500 µg/L, while age-adjusted cut-off value is set as patient's age×10 µg/L. We compared the sensitivity and specificity using the 2 cut-off values in confirming or excluding the diagnoses of DVT. RESULTS: The study population consisted of 624 patients [mean age(76.4 ± 19.3) years], DVT was confirmed in 192 (30.8%) patients. Using Wells score model, 326 patients (52.2%) were scored as unlikely DVT and DVT was confirmed by ultrasonography in 44 patients (13.5%), and 298 patients as likely DVT patients and DVT was confirmed in 148 patients (55.0%). The sensitivity, specificity, positive predictive value, and negative predictive value by conventional and age-adjusted D-dimer cut-off value for diagnosing DVT in low-risk patients evaluated by Wells score model were 95.5%, 40.4%, 20.0%, 98.3% and 95.5%, 61.0%, 27.6%, 87.1%, respectively, and which were 89.9%, 67.3%, 73.1%, 87.1% and 89.2%, 89.3%, 89.2%, 89.3%, respectively, in high-risk patients evaluated by Wells score model. Thus, specificity increased about 20% using age-adjusted D-dimer cut-off value compared with conventional D-dimer cut-off value. CONCLUSION: The age-adjusted D-dimer cut-off value combined with clinical probability evaluation could increase diagnosing specificity of DVT in elderly patients.

[Age-related reference ranges of serum prostate-specific antigen in men free of prostate cancer in Beijing].

OBJECTIVE: To determine the age-related normal ranges of serum prostate-specific antigen (PSA) level in men free of prostate cancer in Beijing. METHODS: Form April 2010 to October 2011, 1611 healthy men undergoing routine physical examinations in our hospital were enrolled and received examinations with serum PSA test, digital rectal examination and transrectal ultrasound. The men with abnormalities in any two of the three examinations were referred to a prostate biopsy. The men with normal results in any two of the examinations or with a negative biopsy finding were defined as men without prostate cancer. Men with a prior history of prostate cancer/surgery or with urinary tract infection/obstruction were excluded. RESULTS: A total of 1572 men without prostate cancer were finally included in this study and stratified into 5 age groups, namely 40 to 49, 50 to 59, 60 to 69, 70 to 79, and older than 80 years groups. The median PSA values (95th percentile ranges) of these age groups were 0.506 (1.565), 1.04 (2.920), 1.16 (4.113), 1.34 (5.561), and 2.975(7.285), respectively, and the 25th to 75th percentiles were 0.343 to 0.923, 0.663 to 1.580, 0.693 to 2.203, 0.789 to 2.368, and 1.188 to 4.295, respectively. The serum PSA value was positively correlated with age (r=0.314, P<0.001). CONCLUSION: Using the age-related reference ranges for PSA can increase the sensitivity for screening prostate cancer in younger men and decrease the biopsy rate in elderly patients.

The cellular immune mechanism after transfer of chemically extracted acellular nerve xenografts.

Severe peripheral nerve defect by injuries causing functional loss require nerve grafting. Autograft has limitations for clinical use because it results in the creation of a new nerve injury and the generation of donor site morbidity. Based on these limitations, nerve allografts and xenografts provide a readily accessible alternative strategy. The aim of the present study was to observe the immune mechanism underlying the rejection of chemically extracted acellular nerve xenografts, and further evaluate immunogenicity of chemically treated acellular nerve grafts for clinical applications. A total of 160 BALB/c mice were randomly divided into a negative contrast group (NC, 40 mice), a fresh autograft group (AG, 40 mice), a fresh xenogeneic nerve group (FXN, 40 mice) and a chemically extracted acellular xenogeneic nerve group (CEXN, 40 mice). Various types of nerve grafts were implanted into the thigh muscle of BALB/C mice in the corresponding groups. At 3, 7, 14 and 28 days post-operation, the mice (10 mice from each group) were sacrificed and their spleens were extracted. The spleens were ground into paste. The erythrocytes and other cells were lysed using distilled water and the T lymphocytes were collected. Fluorescein isothiocyanate (FITC) -labeled monoclonal antibodies (CD3, CD4, CD8, CD25, IL-2, IFN-γ and TNF-α) were then added to the solution. The Fluorescence Activated Cell Sorting (FACS) was used to determine the positivity rate of the cells combined with the monoclonal antibodies above. No significant statistical differences were observed between the CEXN, NC and AG groups, so that no obvious immune rejections were observed among the chemically extracted acellular nerve xenografts.

Reference Ranges of Age-Related Prostate-Specific Antigen in Men without Cancer from Beijing Area.

BACKGROUND: To determine the normal ranges of serum age-related prostate-specific antigen (PSA) level in men from Beijing area without cancer. METHODS: In this cross sectional study, form April 2010 to October 2011, 1611 healthy men undergoing a routine health check-up in our hospital and all men received three examinations including serum PSA test, digital rectal ex-amination and transrectal ultrasound. Men with any two abnormal results of the three examinations were undergone a prostate biopsy. Men with any two normal results of the three examinations or with negative biopsy were defined as men without cancer. Men with a prior history of prostate cancer/surgery or with urinary tract infection/obstruction were excluded. 1572 men without cancer were recruited into the study finally and were stratified into 10-year age groups: 40 to 49, 50 to 59, 60 to 69, 70 to 79, and older than 80. RESULTS: The median PSA value (95th percentile range) was 0.506(1.565), 1.04(2.920), 1.16(4.113), 1.34(5.561)and 2.975 (7.285) for each age group respectively, and the 25th percentile to 75 percentile was 0.343 to 0.923, 0.663 to 1.580, 0.693 to 2.203, 0.789 to 2.368 and 1.188 to 4.295 respectively. The serum PSA value is directly correlated with age (r=0.314, P＜0.001). CONCLUSIONS: Use the age-related range for PSA increases the sensitivity in younger men and decreases the biopsy rate in older patients.

[Expressions of telomerase reverse transcriptase and vascular endothelial growth factor and their correlation in prostate cancer].

OBJECTIVE: To investigate the expressions of telomerase reverse transcriptase (TRT) and vascular endothelial growth factor (VEGF) and their correlation in prostate cancer (PCa). METHODS: TRT and VEGF expressions were assayed in 30 cases of PCa and 30 cases of benign prostatic hyperplasia (BPH) by means of immunohistochemistry (SP) combined with computer assisted image analysis. RESULTS: The expression of TRT was detected in 19 of the 30 cases of PCa and 5 of 30 cases of BPH, and that of VEGF in 23 of the 30 PCa and 14 of the 30 BPH patients. TRT and VEGF expressions were significantly higher in cancer tissues than in BPH (P < 0.05). A significant correlation was observed between TRT and VEGF expressions (r = 0.8333, P < 0.05). CONCLUSION: The expression of TRT or VEGF might be a malignant phenotype in PCa. The expression of TRT is significantly correlated with that of VEGF, but the mechanisms are yet to be further studied.

Correlation between hypoechoic nodules on ultrasonography and benign hyperplasia in the prostatic outer gland.

OBJECTIVE: The purpose of this investigation was to study the correlation between hypoechoic nodules detected on ultrasonography and benign hyperplasia in the prostatic outer gland (POG) diagnosed by transrectal ultrasonography (TRUS)-guided biopsies. METHODS: The TRUS-guided biopsies were performed on 472 patients suspected of having prostate cancer. Specimens obtained by biopsies were independently assessed by pathologists at 3 hospitals. RESULTS: The histologic results of 310 patients (65.68%) were benign. Focal hypoechoic nodules located in the POG were found in 240 patients (50.8%) on TRUS scans. Among them, in 22 patients (9.17% of the 240 patients with hypoechoic nodules), benign hyperplasia was found in focal hypoechoic nodules located in the POG. Focal nodules were seen as well circumscribed with an ovoid shape and smooth surface in 18 patients. CONCLUSIONS: Benign hyperplasia may sometimes originate in the POG and may appear as a hypoechoic nodule, similar to the appearance of prostate cancer.