Management of Suspected Peripheral Vascular Injuries in Orthopedic Trauma.

OBJECTIVE: In orthopedic trauma, identification of extremity trauma combined with vascular injury is challenging. Missed diagnosis may result in amputation or even death. The purpose of this study was to investigate whether physical examination combined with handheld vascular ultrasound Doppler examination could be an effective method of screening for peripheral vascular injury and to explore the characteristics of vascular injuries in orthopedic trauma patients. METHODS: Retrospective analysis of patients in the emergency department of orthopedic trauma in our hospital from January 2022 to October 2023. Physical examination combined with handheld vascular ultrasound Doppler examination was used as a screening method for suspected vascular injuries. Patients with suspected vascular injury would undergo further angiography and receive multidisciplinary treatment. Angiography was used as the gold standard for diagnosing vascular injuries. Patient demographics, mechanism of injury, location and type of injury, angiographic results, surgical notes, and early treatment outcome data were recorded. RESULTS: A total of 55 cases (58 limb injuries) with suspected vascular injury were ultimately included. Angiography revealed that 53 cases (55 limbs, positive rate 94.8%) were considered to have confirmed vascular injuries. Forty-three were male (81.1%) and 10 were female (18.9%), with mean age 44.1 ± 16.6 years. The main mechanism of injury was traffic accident (30, 56.7%). Most common site of vascular injuries was knee joint (30/55, 54.5%), and popliteal artery (23, 47.9%) was the most commonly injured blood vessel. After multidisciplinary collaborative treatment, overall patient mortality was 3.8% (2/53), and limb survival rate among surviving patients was 81.1% (43/53) in our study. CONCLUSION: In orthopedic trauma, "Hard signs" and "soft signs" combined with handheld vascular ultrasound Doppler examination were effective ways to screen for suspected vascular injuries. Most limbs had associated fractures or dislocations at the site of vascular injury. Collaboration of vascular surgery, microsurgery and orthopedic trauma may help improve patients' prognosis.

Traumatic proximal tibiofibular fracture and dislocation.

BACKGROUND: Traumatic proximal tibiofibular fracture and dislocation (PTFD) have been rarely studied and are easily missed in clinical practice. PTFD is considered a marker of severely traumatized knees. The purpose of this study was to retrospectively analyze the incidence and impact of PTFD in traumatized knees with vascular injury. METHODS: Patients with knee trauma and vascular injury were included from January 2022 to October 2023. X-rays and CT scans of included patients were retrospectively analyzed to determine the presence of PTFD. Patients were further divided into PTFD group and non-PTFD group for further comparative analysis. RESULTS: A total of 27 patients (28 limbs) were included. Incidence of PTFD was 39.3% (11/28) in traumatic knee with vascular injury, including 8 anterolateral dislocations and 3 posteromedial dislocations. PTFD group had significantly more limbs with open injuries compared with non-PTFD group (10/11 VS 7/17, p<0.05). Amputation rate of PTFD group was as high as 40% (4/10), compared to 23.5% (4/17) in non-PTFD group. However, the difference between two groups was not statistically significant (p>0.05). CONCLUSIONS: PTFD was easily overlooked or missed. In traumatized knees with vascular injury, incidence of PTFD was high. The presence of PTFD might indicate severe knee trauma and the possibility of open injury. Although there was no significant difference compared with non-PTFD group, PTFD group had a relatively high amputation rate of 40%.

Effects of Salt Stress on Physiological and Agronomic Traits of Rice Genotypes with Contrasting Salt Tolerance.

Salinity is one of the major constraints to crop production. Rice is a main staple food and is highly sensitive to salinity. This study aimed to elucidate the effects of salt stress on physiological and agronomic traits of rice genotypes with contrasting salt tolerance. Six contrasting rice genotypes (DJWJ, JFX, NSIC, HKN, XD2H and HHZ), including three salt-tolerant and three salt-sensitive rice genotypes, were grown under two different salt concentrations (0 and 100 mmol L-1 NaCl solution). The results showed that growth, physiological and yield-related traits of both salt-sensitive and salt-tolerant rice were significantly affected by salt stress. In general, plant height, tiller number, dry weight and relative growth rate showed 15.7%, 11.2%, 25.2% and 24.6% more reduction in salt-sensitive rice than in salt-tolerant rice, respectively. On the contrary, antioxidant enzyme activity (superoxide dismutase, peroxidase, catalase), osmotic adjustment substances (proline, soluble protein, malondialdehyde (MDA)) and Na+ content were significantly increased under salt stress, and the increase was far higher in salt-tolerant rice except for MDA. Furthermore, grain yield and yield components significantly decreased under salt stress. Overall, the salt-sensitive rice genotypes showed a 15.3% greater reduction in grain yield, 5.1% reduction in spikelets per panicle, 7.4% reduction in grain-filling percentage and 6.1% reduction in grain weight compared to salt-tolerant genotypes under salt stress. However, a modest gap showed a decline in panicles (22.2% vs. 22.8%) and total spikelets (45.4% vs. 42.1%) between salt-sensitive and salt-tolerant rice under salinity conditions. This study revealed that the yield advantage of salt-tolerant rice was partially caused by more biomass accumulation, growth rate, strong antioxidant capacity and osmotic adjustment ability under salt stress, which contributed to more spikelets per panicle, high grain-filling percentage and grain weight. The results of this study could be helpful in understanding the physiological mechanism of contrasting rice genotypes' responses to salt stress and to the breeding of salt-tolerant rice.

[Orthopaedic robot assisted femoral neck dynamic cross fixation system for the treatment of femoral neck fractures].

OBJECTIVE: To explore and compare the clinical efficacy of orthopedic robot assisted femoral neck system （FNS） and traditional manual FNS in the treatment of femoral neck fractures in middle-aged and young people. METHODS: The clinical data of 62 consecutive patients with femoral neck fracture and age less than 65 years old admitted to the Intelligent Orthopaedic Department of Beijing Jishuitan Hospital from June 2021 to June 2022 were retrospectively analyzed. According to whether orthopedic robot-assisted surgery the patients were divided into two groups：30 patients aged 34 to 56 years old were treated with orthopedic robot assisted FNS internal fixation after closed or limited open reduction（experimental group）； 32 patients aged 33 to 54 years old underwent FNS internal fixation after closed or limited open reduction（control group）. The age, gender, time from injury to admission, average hospital stay, surgical duration, intraoperative bleeding volume, and intraoperative fluoroscopy frequency of two groups of patients were analyzed and compared. The hip joint function in both groups of patients was evaluated using the Harris hip joint scoring standard at 6 months after surgery. RESULTS: All 62 patients with femoral neck fractures successfully completed the surgery. There was no significant difference（P>0.05） between the experimental group and the control group in terms of baseline data such as age, gender, time from injury to admission, time from admission to surgery and the intraoperative bleeding. The surgical duration of the experimental group was significantly shorter than that of the control group [42.1（28.5, 50.7）min vs. 53.4（36.9, 62.5） min, Z=-2.338, P=0.019]. The intraoperative X-ray fluoroscopy frequency of the experimental group was significantly lower than that of the control group[8.0 （6.0, 11.0） times vs. 15.0（13.0, 17.0） times, Z=-5.960, P<0.001]. In terms of postoperative hip joint function, there was no significant difference in Harris score between the two groups of patients at 6-month follow-up（P>0.05）. CONCLUSION: Compared with manual operation of FNS, orthopedic robot assisted FNS in the treatment of femoral neck fractures can help shorten surgical time, reduce intraoperative fluoroscopy frequency, and have similar therapeutic effects on long-term hip joint function recovery.

Eco-evolutionary dynamics of gut phageome in wild gibbons (Hoolock tianxing) with seasonal diet variations.

It has been extensively studied that the gut microbiome provides animals flexibility to adapt to food variability. Yet, how gut phageome responds to diet variation of wild animals remains unexplored. Here, we analyze the eco-evolutionary dynamics of gut phageome in six wild gibbons (Hoolock tianxing) by collecting individually-resolved fresh fecal samples and parallel feeding behavior data for 15 consecutive months. Application of complementary viral and microbial metagenomics recovers 39,198 virulent and temperate phage genomes from the feces. Hierarchical cluster analyses show remarkable seasonal diet variations in gibbons. From high-fruit to high-leaf feeding period, the abundances of phage populations are seasonally fluctuated, especially driven by the increased abundance of virulent phages that kill the Lachnospiraceae hosts, and a decreased abundance of temperate phages that piggyback the Bacteroidaceae hosts. Functional profiling reveals an enrichment through horizontal gene transfers of toxin-antitoxin genes on temperate phage genomes in high-leaf season, potentially conferring benefits to their prokaryotic hosts. The phage-host ecological dynamics are driven by the coevolutionary processes which select for tail fiber and DNA primase genes on virulent and temperate phage genomes, respectively. Our results highlight complex phageome-microbiome interactions as a key feature of the gibbon gut microbial ecosystem responding to the seasonal diet.

Drugs that act in the lymphatic system and lymphatic drug delivery: review and perspective / 药学学报

The lymphatic system, as well as pathological changes of the lymphatic system, underlies the progress of an array of diseases and conditions, including cancer, inflammation and autoimmune disorders, infectious diseases and metabolic syndrome. A variety of biological targets in the lymphatic system can be employed to modulate these high-burden diseases, and the pharmacokinetics and drug delivery strategies in the context of lymphatics are of critical importance to optimise drug exposure to lymphatic-related targets. As such, research and drug development in this field has gained increasing attention in recent years. This article aims to provide an overview of pharmaceutical research with a focus on the lymphatic system and therapeutic targets within the lymphatics, followed by lymphatic drug delivery approaches, which may be of interest for researchers in academia, pharmaceutical industry and regulatory sciences.

How flare-up of small and medium enterprises intensifies carbon emissions in Asian and European regions: a panel analysis.

SMEs (small and medium enterprises) contribute substantially to the global and national economies. So, their activities can significantly affect the ecosystem; however, environmental performance is primarily targeted at larger corporations. Therefore, this study measures the SMEs' impact on environmental quality through CO2 emissions. For this purpose, data on twenty-five Asian and European economies from 2005 to 2020 is utilized, and the effect of SMEs on the environment is measured in the light of the EKC hypothesis. In order to validate and test the influence of SMEs on the environment, the pooled mean group (PMG) model with cointegration approaches is utilized. The results show that the flare-up of small and medium enterprises increases environmental pollution through high carbon emissions at micro levels. Thus, the study suggests that governments, SMEs, and other stakeholders have to create strategies and regulations targeted at SMEs to minimize their negative environmental impact.

Gut microbiome responds compositionally and functionally to the seasonal diet variations in wild gibbons.

Wild animals may encounter multiple challenges especially food shortage and altered diet composition in their suboptimal ranges. Yet, how the gut microbiome responds to dietary changes remains poorly understood. Prior studies on wild animal microbiomes have typically leaned upon relatively coarse dietary records and individually unresolved fecal samples. Here, we conducted a longitudinal study integrating 514 time-series individually recognized fecal samples with parallel fine-grained dietary data from two Skywalker hoolock gibbon (Hoolock tianxing) groups populating high-altitude mountainous forests in western Yunnan Province, China. 16S rRNA gene amplicon sequencing showed a remarkable seasonal fluctuation in the gibbons' gut microbial community structure both across individuals and between the social groups, especially driven by the relative abundances of Lanchnospiraceae and Oscillospiraceae associated with fluctuating consumption of leaf. Metagenomic functional profiling revealed that diverse metabolisms associated with cellulose degradation and short-chain fatty acids (SCFAs) production were enriched in the high-leaf periods possibly to compensate for energy intake. Genome-resolved metagenomics further enabled the resolving metabolic capacities associated with carbohydrate breakdown among community members which exhibited a high degree of functional redundancy. Our results highlight a taxonomically and functionally sensitive gut microbiome actively responding to the seasonally shifting diet, facilitating the survival and reproduction of the endangered gibbon species in their suboptimal habitats.

Early arrival did not ensure the early acquisition of intravenous thrombosis for acute ischemic stroke during the COVID-19 pandemic.

BACKGROUND: Intravenous thrombolysis (IVT) in acute ischemic stroke (AIS) is a time-dependent treatment with a narrow therapeutic time window, in which the time delay could result from the deadline effect. METHODS: One hospital-based cohort was recruited to detect the factors contributing to the deadline effect, where patients with the deadline effect were defined as those who were presented with the onset-to-door time (ODT) in the first 50%, while the door-to-needle time (DNT) was in the last quartile. DNT (in-hospital delay) was further subdivided into several time intervals [door-to-examination time (DET), door-to-imaging time (DIT), door-to-laboratory time (DLT), and decision-making time (DMT) of the patients or their proxies. RESULTS: A total of 186 IVT cases were enrolled, of which 17.2% (32/186) suffered a delay of the deadline effect. The median age was 66 years, and 35.5% were female. Baseline characteristics were similar between the two groups (all p > .05). For the comparisons of the time intervals, DIT (26 versus 15 min, p = .001) was significantly longer in the group with deadline effect, while the differences of DET, DLT, DMT, and ONT did not reach statistical significance (all p > .05). Upon multivariable adjustment in the binary logistic regression model, longer DIT [odds ratio (OR), 1.076; 95% confidence interval (CI), 1.036-1.118; p < .001], and history of coronary heart disease (OR, 3.898; 95%CI, 1.415-10.735; p = .008) were independently associated with deadline effect in the binary logistic regression model, while admitted in the working day (OR, 0.674; 95%CI, 0.096-0.907; p = .033), and having medical insurance (OR, 0.350; 95% CI, 0.132-0.931; p = .035) were negatively associated with the deadline effect. CONCLUSIONS: A speed-safety tradeoff phenomenon from the deadline effect was observed in 17.2% of IVT cases during the COVID-19 pandemic, where longer DIT contributed a lot to this time delay. Patients without medical insurance, or admitted in official holidays were more likely to experience a delay of the deadline effect.

Osteoblasts Regulate the Expression of ADAMTS and MMPs in Chondrocytes through ERK Signaling Pathway.

OBJECTIVE: Degradative enzymes such as matrix metalloproteinase (MMP) and disintegrin metalloproteinase with platelet thrombin-sensitive protein-like motifs (ADAMTS) play a key role in the development of osteoarthritis (OA). We aimed to investigate the effects of OA subchondral osteoblasts on the expression of ADAMTS4, ADAMTS5, MMP-3, MMP-9, and MMP-13 in chondrocytes and the regulation of mitogen-activated protein kinase (MAPK) signaling pathway. METHODS: A rat knee OA model was constructed by cutting the anterior cruciate ligament of the knee joints, and normal rat articular cartilage chondrocytes (N-ACC), OA rat articular cartilage chondrocytes (O-ACC), normal subchondral bone osteoblasts (N-SBO), and OA subchondral bone osteoblasts (O-SBO) were isolated and extracted. The expressions of O-ACC and O-SBO COL1 and COL2 were detected respectively. Chondrocytes were identified by immunofluorescence of COL2 and toluidine blue staining, and osteoblasts were identified by COL1 immunofluorescence, alkaline phosphatase (ALP), and Alizarin Red staining. Gene expression of COL1, COL2, and aggrecan in normal chondrocytes and OA chondrocytes, and gene expression of osteoblast ALP and osteocalcin (OCN) were detected by RT-PCR to identify the two chondrocytes and the two osteoblast phenotypes. The constructing N-ACC group, O-ACC group, N-ACC + N-SBO group, N-ACC + O-SBO group, O-ACC + N-SBO group, O-ACC + O-SBO group, I + N-ACC + O-SBO group, and I + O-ACC + O-SBO group cell cultures, and the expression of ERK, ADAMTS4, ADAMTS5, MMP-3, MMP-9, and MMP-13 genes in chondrocytes cultured for 0, 24, 48, and 72 h were detected by RT-PCR. The protein expressions of pERK, ADAMTS4, ADAMTS5, MMP-3, MMP-9, and MMP-13 were detected by Western blot. RESULTS: · The X-ray showed that the knee joint space of the affected limb became narrow.. · The results of RT-PCR of COL2 and aggrecan gene in OA and normal chondrocytes suggest that the relative expression of COL2 in OA articular chondrocytes (0.24 ± 0.07) is significantly lower than that in normal cartilage (0.61 ± 0.07) (p < 0.05). The relative expression of AGG (0.37 ± 0.16) in OA chondrocytes was significantly lower than that of normal chondrocytes AGG (1.30 ± 0.25) (p < 0.05). The expression of COL1 was very low, and was not statistically significant.. · The results of RT-PCR of the osteoblast ALP and OCN gene indicated that gene expression of ALP (12.30 ± 1.17) and OCN (20.47 ± 4.19)was upregulated when compared with the relative expression of ALP (4.66 ± 0.71) (p < 0.05) and OCN (12.17 ± 2.76) (p < 0.05) in normal osteoblasts, indicating that osteoblasts of OA have greater osteogenic potential than normal osteoblasts.. · The expressions of ADAMTS4, ADAMTS5, MMP-3, MMP-9, and MMP-13 genes and proteins in OA chondrocytes or normal chondrocytes were basically unchanged when they were cocultured with normal osteoblasts. Indirect coculture of OA osteoblasts and chondrocytes could promote the expression of ADAMTS4, ADAMTS5, MMP-3, MMP-9, and MMP-13 genes and proteins in chondrocytes. Overexpression of ADAMTS and MMP in coculture systems can be reversed by MAPK-ERK inhibitors.. CONCLUSIONS: · OA subchondral bone osteoblasts can promote the overexpression of ADAMTS and MMPs in chondrocytes.. · The ERK signaling pathway may be involved in the regulation of the effect of subchondral bone osteoblasts on chondrocytes..

IgG4-related kidney disease complicated with membranous nephropathy in one patient with multiple metastatic lung malignancies / 中华肾脏病杂志

Here we report the diagnosis and treatment of a rare IgG4-related kidney disease with nephrotic syndrome as the first manifestation. A 62-year-old male patient, presented with edema in both lower limbs and foam urine, had a history of "lung malignant tumor with brain and lymph node metastasis". The increase of IgG4 and decrease of glomerular filtration rate were detected at admission, and the pathological consideration of renal biopsy was membranous nephropathy with IgG4-related tubulointerstitial nephritis. After the combination of low-dose glucocorticoids therapy and rituximab treatment, the patient showed good prognosis in a 9 month follow-up.

Giant myoepithelial carcinoma of the nuchal region: a case report and literature review / 临床耳鼻咽喉头颈外科杂志

Myoepithelioma, also known as malignant myoepithelioma, is a rare malignant tumor originating from myoepithelial cell. This article reports a patient with a huge tumor in the neck and left elbow who underwent fine needle aspiration under local anesthesia. The pathological diagnosis was a myoepithelioma. Under general anesthesia, giant tumors in the lower neck, posterior cranial fossa, neck, and left elbow were removed, and postoperative pathology showed that they were all myoepithelial tumors. Immunohistochemistry showed AE1/AE3 (+), P63 (+), CK7 (+), CK5 (+), and CD138 (+). The clinical characteristics and diagnosis and treatment process of this case are reported and relevant literature is reviewed.

Poorly differentiated neuroendocrine carcinoma of the tongue base: a case report / 临床耳鼻咽喉头颈外科杂志

Neuroendocrine carcinoma(NEC) is a malignant tumor derived from neuroendocrine cells, with distinct clinical, morphological and immunohistochemical characteristics. Neuroendocrine carcinoma of the head and neck is very rare in clinic. Larynx is the most common affected site, and the root of the tongue is extremely rare. The clinical manifestations are mainly eating pain, cauliflower like mass in the mouth, and ulcerative lesions that have not healed for a long time. Maxillofacial MRI and contrastenhanced CT are the most commonly used examination tools for such diseases, which can detect the spaceoccupying lesions of tumors. Neuroendocrine granules found in the cytoplasm under pathological light microscope can be diagnosed as neuroendocrine carcinoma. However, for most cases, it is difficult to make a diagnosis only under light microscope, and it is often necessary to make a diagnosis by means of immunohistochemistry and other technical means. This paper reports a case of neuroendocrine carcinoma of the root of the tongue, introduces its characteristics, diagnosis and treatment, and reviews the relevant literature of this case.

Mechanism of Natural Plant Essential Oil in Intervention in Type 2 Diabetes Mellitus： A Review / 中国实验方剂学杂志

Type 2 diabetes mellitus （T2DM） is a heterogeneous disease with insulin deficiency and insulin resistance （IR） as the main etiology and is often accompanied by complications. Volatile oil is a volatile oily liquid extracted from natural plants， which has many pharmacological effects such as regulating Qi， relieving pain， inhibiting bacteria， and reducing inflammation. In recent years， there have been numerous reports on the treatment of T2DM by natural plant volatile oil and its effective components， which has become one of the new directions in the treatment of T2DM. With natural plant essential oil and its active components as the starting point， this paper comprehensively analyzed and summarized the material basis， mechanism， and signaling pathways of essential oil in the treatment of T2DM and its complications in China and abroad in recent years， and focused on the inhibitory effect of essential oil and its active components， such as carvacrol， paeonol， and β-caryophylene， on IR to improve T2DM by protecting pancreatic β-cells， inhibiting α-glucosidase activity， regulating the abundance and diversity of intestinal microbiota， and regulating glucose transporter protein type4 （GLUT4）， adenylate 5′-monophosphate-activated protein kinase （AMPK）， phosphatidylinositol-3 kinase （PI3K）/protein kinase B （Akt） signaling pathways to provide some references for the volatile oil intervention in T2DM and the development of new green antidiabetic drugs.

Testicular infarction due to polyarteritis nodosa: a case report and literature review / 现代泌尿外科杂志

【Objective】 To report a case of testicular infarction due to polyarteritis nodosa (PAN), and to discuss its clinical diagnosis and treatment based on relevant literatures at home and abroad, so as to have a better understanding of this rare disease. 【Methods】 Clinical data of a case complaining of scrotal pain who was initially diagnosed as testicular torsion and later confirmed to be testicular infarction due to PAN were retrospectively analyzed, and relevant literatures were reviewed. 【Results】 With glucocorticoid, vasodilator and antioxidant treatment, the patient’s testicular blood flow was improved. 【Conclusion】 Testicular infarction due to PAN is a rare disease which is difficult to diagnose timely. The diagnosis depends on biopsy and the standards formulated by American College of Rheumatology (ACR). Good prognosis can be achieved with timely diagnosis and correct treatment.

Application progress on contrast-enhanced ultrasound in acute rejection after kidney transplantation / 器官移植

Early diagnosis of acute rejection is of significance for the protection of renal allograft function. Pathological puncture biopsy is the gold standard for the diagnosis of acute rejection of renal allografts. Nevertheless, it may provoke multiple complications, such as bleeding, infection and renal parenchymal injury, which limit its widespread application. In recent years, the sensitivity of contrast-enhanced ultrasound in the diagnosis of acute rejection has been constantly improved. Ultrasound-targeted microbubble technique has further enhanced the diagnostic specificity of contrast-enhanced ultrasound, making it possible to replace pathological puncture biopsy. Besides, in the field of acute rejection treatment, microbubble ultrasonic cavitation may promote local delivery of immunosuppressants by inducing sonoporation and exhibit anti-rejection effect. In this article, the application of contrast-enhanced ultrasound in the diagnosis and treatment of acute rejection after kidney transplantation was reviewed, aiming to provide reference for widespread application of contrast-enhanced ultrasound in kidney transplantation.

T2 mapping and readout segmentation of long variable echo-train diffusion-weighted imaging for the differentiation of parotid gland tumors.

OBJECTIVE: To investigate the diagnostic value of radial turbo-spin-echo (TSE) T2 mapping and readout segmentation of long variable echo-train diffusion-weighted imaging (RESOLVE DWI) for the differentiation of parotid gland tumors. MATERIALS AND METHODS: One hundred and fifty-four patients with histopathologically confirmed parotid gland tumors were retrospectively recruited from June 2018 to May 2021 at the First Affiliated Hospital of Zhengzhou University. There were 111 benign tumors and 43 malignant tumors. Benign tumors were further divided into pleomorphic adenomas (n = 69) and Warthin's tumors (n = 26). All patients were scanned using T2 mapping and RESOLVE DWI. T2 and ADC values and a combination of the two methods were compared and analyzed for the ability to differentiate parotid gland tumor types. RESULTS: The T2 and ADC values of benign tumors were significantly higher than those of the malignant tumors (127.97 ± 56.29 ms vs 97.53 ± 45.24 ms, 1.27 ± 0.40 × 10-3 mm2/s vs 1.00 ± 0.39 × 10-3 mm2/s, all P < 0.05). The area under the curve (AUC) of the T2 and ADC values for differentiating (1) benign and malignant parotid tumors, (2) pleomorphic adenomas and Warthin's tumors, (3) pleomorphic adenomas and malignant tumors, and (4) Warthin's tumors and malignant tumors were 0.709 and 0.715, 0.918 and 0.994, 0.748 and 0.774, and 0.665 and 0.659, respectively, with no significant differences observed between the T2 and ADC values (all P > 0.05). There were no significant differences in these values among the three tumor groups (malignant tumor, pleomorphic adenoma, and Warthin's tumor groups, all P > 0.05). CONCLUSIONS: T2 mapping and RESOLVE DWI can be used to differentiate various parotid gland tumors. T2 values are comparable to ADC values.

The Regularity of Stress Shielding in Internal Fixation Characterized by Hydromechanics.

Stress shielding is an important factor in the internal fixation of a fracture. To explore the regularity of stress shielding in internal fixation, a simplified model of a comminuted femoral shaft fracture bridged by a locking plate was established and finite element analysis was performed to analyze the load distribution between the plate and femur from the proximal end of the femur to the fracture line and investigate the stress shielding degree of the plate on the bone. The stress, deformation, and axial compressive force distribution of four internal fixation schemes under compression were obtained, and the stress shielding degrees on each section was calculated. To compare the regularity of stress shielding and flow distribution, the relationship between the compressive force increment and stress shielding degree was established. The normalized curves of compressive force increment with the plate section position were compared with the flow distribution in a Z-type manifold, a parallel pipe system similar to an internal fixation system in structure and working characteristics. For quantitative comparison, the similarity between normalized curves of the compressive force increment and simulated flow distribution was calculated. The regularity of load distribution along the section position of the plate was similar to the flow distribution in the Z-type manifold. Therefore, the flow distribution pattern of the Z-type manifold can be used to characterize the regularity of load distribution in internal fixation. This study provided a new method to characterize the stress shielding degree of a locking plate on bone.

Application of project-based learning in clinical teaching of radiation physics for radiotherapy residents / 中华放射肿瘤学杂志

Objective:To observe the effect of project-based learning (PBL) in the clinical teaching of radiation physics.Methods:Thirty-two residents specializing in radiotherapy were included in the study. In the experimental group ( n=16), PBL was adopted, while traditional clinical teaching method was employed in the control group ( n=16). After the rotation, the assessment was conducted, as well as a questionnaire survey was performed, including five aspects: overall satisfaction, understanding of radiation physics knowledge, learning motivation, learning burden, and learning efficiency. Results:The assessment score in the experimental group was 86.31±5.41, which was higher than 75.28±5.91 in the control group, and the difference was statistically significant. Residents in the experimental group were satisfied with the effect of PBL.Conclusion:Compared with the traditional teaching method, PBL can improve the learning motivation, efficiency, and performance of radiotherapy residents, which is highly recognized by the residents.