Laser Additive Manufacturing of TC4/AlSi12 Bimetallic Structure via Nb Interlayer.

The TC4/AlSi12 bimetallic structures (BS) with Nb interlayer transition were fabricated by laser additive manufacturing (LAM). The results showed that the TC4/AlSi12 BS with Nb interlayer prepared with optimized process parameters can be divided into three regions (the TC4 region, Nb region and the AlSi12 region) and two interfaces (the TC4/Nb interface and the Nb/AlSi12 interface). The high melting point (Ti, Nb) solid solution formed in the Nb region acted as a diffusion barrier between the TC4 alloy and the AlSi12 alloy, thereby effectively inhibiting the formation of Ti-Al intermetallic compounds (IMCs). With the decrease of the laser output power for AlSi12 deposition, the NbAl3 IMC changed from layered to dispersed distribution, while γ-TiAl and Ti5Si3 IMC disappeared, thus significantly reducing the crack susceptibility of the BS deposited layer. The tensile strength of TC4/AlSi12 BS with Nb interlayer was about 128MPa, and the fracture was located near the Nb/AlSi12 interface.

Decreased Transition Rate From Situational Insomnia to Chronic Insomnia by One-Week Internet Cognitive Behavioral Treatments for Insomnia During the COVID-19 Pandemic.

Purpose: The purpose of the study was to determine the long-term effects of one-week self-guided internet cognitive behavioral treatments for insomnia (CBTI) on situational insomnia during the COVID-19 pandemic. Patients and Methods: The participants with situational insomnia (n = 194) were recruited from March 2020 to April 2020 in Guangzhou, China. The insomnia severity index (ISI), pre-sleep arousal scale (PSAS), and hospital anxiety and depression scale (HADS) were evaluated at baseline and a one-week internet CBTI program was delivered to all individuals. The participants were divided into the complete treatment group (the participants completed all seven modules of the CBTI course, n = 75), and the incomplete treatment group (the participants completed 0-6 modules of the CBTI course, n = 119). A total of 135 participants completed the post-intervention assessments. At 3 months follow-up, a total of 117 participants (complete treatment group: n = 51; incomplete treatment group: n = 66) completed the assessments of the ISI, PSAS and HADS. The transition rate from situational insomnia to chronic insomnia (duration of insomnia ≥ 3 months and ISI ≥ 8) was calculated in the two groups. Linear mixed effect model was used to investigate the effect of group (between the two groups), time (baseline vs. follow-up), and interaction (group x time) on various questionnaire score. Results: The transition rate from situational insomnia to chronic insomnia was significantly lower in the complete treatment group compared to the incomplete treatment group (27.5%, 14/51 vs. 48.5%, 32/66, p = 0.023). There were significant differences in group effect (p = 0.032), time effect (p = 0.000) and group × time effect (p = 0.048) between the two groups in the ISI total score. The ISI total scores decreased in both groups during follow-up compared to their baseline values, with a greater magnitude of decrease in the complete treatment group. There were no significant group x time effects between the two groups in the PSAS-total score, PSAS-somatic, PSAS-cognitive score, HADS total score, HADS anxiety score or HADS depression score. Conclusion: Our results suggested that one-week self-guided internet CBTI prevented the development of chronic insomnia from situational insomnia during the COVID-19 pandemic.

The Influence of Heat Treatment Temperature on Microstructures and Mechanical Properties of Titanium Alloy Fabricated by Laser Melting Deposition.

Ti-6Al-4V (TC4) titanium alloy parts were successfully fabricated by laser melting deposition (LMD) technology in this study. Proper normalizing temperatures were presented in detailed for bulk LMD specimens. Optical microscope, scanning electron microscopy, X-ray diffraction, and electronic universal testing machine were used to characterize the microstructures, phase compositions, the tensile properties and hardness of the TC4 alloy parts treated using different normalizing temperature. The experimental results showed that the as-fabricated LMD specimens' microstructures mainly consisted of α-Ti phase with a small amount of ß-Ti phase. After normalizing treatment, in the area of α-Ti phase, the recrystallized length and width of α-Ti phase both increased. When normalizing in the (α + ß) phase field, the elongated primary α-Ti phase in the as-deposited state was truncated due to the precipitation of ß-Ti phase and became a short rod-like primary α-Ti phase. In as-fabricated microstructure, the ß-Ti phase was precipitated between different short rod-shaped α-Ti phases distributed as basketweave. After normalizing treatment at 990 for two hours with subsequent air cooling, the TC4 titanium alloy had significant different microstructures from original sample produced by LMD. The normalizing treatment methods and temperature can be qualified as a prospective heat treatment of titanium alloy fabricating by laser melting deposition.

Predictors of primary patency after percutaneous balloon angioplasty for stenosis of Brescia-Cimino hemodialysis arteriovenous fistula.

OBJECTIVE: Percutaneous transluminal balloon angioplasty (PTA) is recommended as the first choice to treat stenosis of Brescia-Cimino arteriovenous fistulas (B-C AVFs). The ability to predict which B-C AVFs are at risk for recurrent stenosis post-PTA would allow closer monitoring of patients, and possibly result in surgical intervention rather than repeat PTA. The purpose of this study was to identify predictive factors of primary patency after PTA in B-C AVFs. METHODS: Patients diagnosed with B-C AVF primary stenosis and treated by PTA between November 2013 and March 2018 were included in the study. Patient and stenotic lesion characteristics and PTA procedure factors were included in the analysis. The Kaplan-Meier method was used to analyze the primary patency rate. Cox proportional hazard regression analysis was used to identify factors predictive of decreased primary patency. RESULTS: 74 patients (35 males, 39 females) with a mean age of 61.68 ± 11.44 years (range, 36-84 years) were included in the study. The mean B-C AVF age was 16.34 ± 12.93 months (range, 2-84 months), and the median primary patency time was 7.79 ± 0.48 months. Cox proportional hazard regression analysis revealed stenosis location at the inflow artery [hazard ratio (HR)=3.83, 95% confidence interval (CI): 1.46-10.09] or anastomosis (HR = 1.90, 95% CI: 1.09-3.32), dilation >2 times during PTA (HR = 2.30, 95% CI: 1.22-4.34), and residual stenosis >30% (HR = 2.42, 95% CI: 1.26-4.63) were significantly associated with decreased patency. CONCLUSION: In conclusion, the primary patency rate of PTA for B-C AVF dysfunction is reduced by dilation >2 times, residual stenosis >30%, and stenosis located at the inflow artery or anastomosis. These results may help in tailoring surveillance programs, multiple PTA, or a proximal re-anastomosis surgery in patients with AVF dysfunction. ADVANCES IN KNOWLEDGE: A number of studies have been conducted to examine the predictors of primary patency after PTA, however, no definitive conclusions have been reached. Our study revealed that stenosis location at the inflow artery or anastomosis, dilation >2 times during PTA, and residual stenosis >30% were the predictors of primary patency after PTA, which may help in tailoring surveillance programs, multiple PTA, or a proximal re-anastomosis surgery in patients with arteriovenous fistulas dysfunction.

Impact of Magnetic Resonance Imaging on Treatment-Related Decision Making for Osteoporotic Vertebral Compression Fracture: A Prospective Randomized Trial.

BACKGROUND The aim of this study was to analyze the impact and usefulness of characteristic signal change of a linear black signal on magnetic resonance imaging (MRI) on treatment-related decision making. MATERIAL AND METHODS Forty-one patients with a linear black signal on MRI were enrolled in this prospective study. They were randomly divided into the percutaneous kyphoplasty (PKP) group (n=24) and the conservative treatment group (n=17). Clinical measures, including visual analog scale (VAS) and short-form 36 (SF-36) questionnaire, were analyzed. Radiographic measures, including anterior vertebral body height, kyphosis angle and rate of bone-union, were evaluated. RESULTS VAS scores were significantly lower in the PKP group than in the conservative treatment group post-treatment and at one-year follow-up. After one year of treatment, the values for physical functioning, physical health, and body pain were significantly higher in the PKP group than in the conservative treatment group (p<0.05). The PKP group had a significantly higher anterior vertebral body height, rate of bone-union, and lower kyphosis angle than the conservative treatment group at one-year follow-up (p<0.05). CONCLUSIONS In patients with a linear black signal detected on MRI, the first-choice treatment should be PKP rather than conservative treatment.

[Treatment of depression fractures of posterolateral tibial plateau through a modified anterolateral approach].

OBJECTIVE: To study the therapeutic effects of posterolateral depression fractures of the tibial plateau through a modified anterolateral approach. METHODS: From February 2011 to January 2012,13 patients with posterolateral depression fractures of the tibial plateau were treated through a modified anterolateral approach. There were 8 males and 5 females, ranging in age from 28 to 59 years old (49.2 years old on average). Data from patients were collected retrospectively as follows: X-ray, time of fracture healing and the complications of fracture healing. The patients were evaluated both clinically and radiologically according to the Rasmussen score system. RESULTS: All the patients were followed up, and the duration ranged from 6 to 18 months (mean 13.7 months). All the patients got bony union. The average radiographic bony union time was 15.1 weeks (ranged, 11 to 17 weeks). No case of secondary articular depression was found. No complications such as malunion or joint stiffness were found. But 1 patient had superficial infection and 1 patient had common peroneal nerve injury. According to the Rasmussen score system,the mean radiological score was 16.50 ± 0.67 (ranged, 13 to 18), and the mean functional score was 25.20 ± 2.21 (ranged, 13 to 30). The mean range of knee motion was (125.3 ± 9.3)° (ranged, 0° to 135°). CONCLUSION: Treatment of depression fractures of posterolateral tibial plateau with a modified anterolateral approach is a safe method with effective exposure, due to its stable fixation and relatively good outcome with minimal soft-tissue complications. It is regarded as an ideal procedure for depression fractures of posterolateral tibial plateau.

Possible contribution of aminopeptidase N (APN/CD13) to migration and invasion of human osteosarcoma cell lines.

Osteosarcoma is the most common primary malignancy of the bone. Aminopeptidase N (APN/CD13), a Zn+2-dependent ectopeptidase localized on the cell surface, is widely considered to influence the invasion mechanism. This study explores the potential involvement of APN in migration and invasion of human osteosarcoma cells in vitro using inhi-bitors and activators of APN. Cells treated with APN inhibitor bestatin displayed decreased migration and invasion in a Boyden chamber Transwell assay. Western blotting revealed reduced levels of mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K) pathway proteins, reduced phosphorylation of p38, ERK1/2 and JNK and decreased levels of NF-κB. Bestatin treatment also lowered APN, matrix metalloproteinase (MMP)-2 and -9 enzymatic activity and their mRNA expression. Reduced MMP-2 and -9 protein levels were also observed. By comparison, cells treated with cytokine interleukin-6 (IL-6), a stimulator of APN, displayed increased migration and invasion. Western blotting revealed increased levels of MAPK and PI3K pathway proteins, phosphorylated p38, ERK1/2 and JNK, and NF-κB. IL-6 treatment also increased APN and MMP-2 and -9 enzymatic activity. An increase of APN, MMP-2 and -9 mRNA levels, and MMP-2 and -9 protein levels was also observed. Together these experiments reveal potential enzymatic and signalling roles for APN in osteosarcoma and establish a starting point for an in-depth analysis of the role of APN in regulating invasiveness. A deeper knowledge about the regulatory mechanisms of APN may contribute to the development of anti-metastatic therapies.

Association between single nucleotide polymorphisms of asporin (ASPN) and BMP5 with the risk of knee osteoarthritis in a Chinese Han population.

The aim of this study was to investigate associations between single nucleotide polymorphisms rs13301537 in asporin (ASPN) and rs373444 in the bone morphogenetic protein 5 (BMP5) gene with knee osteoarthritis (OA) susceptibility in a Chinese Han population. ASPN rs13301537 and BMP5 rs373444 polymorphisms were genotyped in patients with knee OA and age- and sex-matched OA-free controls from a Chinese Han population. A total of 510 patients with knee OA and 520 controls were enrolled in the study. CT and CC genotypes of rs13301537, and variant C, were associated with a significantly increased risk of knee OA. On stratification analysis, the association between the risk of OA and rs13301537 CT heterozygotes compared with TT homozygotes was stronger in females and those aged >65 years. In contrast, the CT and CC genotypes of rs373444 in BMP5 were not significantly associated with the risk of knee OA, even after further stratification analysis according to age or sex. Our results showed that ASPN rs13301537 T to C change and variant C genotype may contribute to knee OA risk in a Chinese Han population.

[Effects of cervical vertebrae degeneration on traumatic cervical cord injury].

OBJECTIVE: To evaluate the effects of cervical vertebrae degeneration on traumatic cervical cord injury. METHODS: From January 2009 to December 2010, 24 patients with cervical cord injury without obvious fractures and dislocations were treated with operation, and their data were retrospectively analyzed. Among them, 16 males and 8 females, aged from 46 to 70 years old with an average of 59.1 years. Patients were divided into light degeneration group (6 cases), moderate degeneration group (10 cases) and severe degeneration group (8 cases), according to the preoperative degenerative degree of cervical vertebrae. Preoperative neurological dysfunction and postoperative neurological recovery were compared according to the JOA scores of Japanese Orthopaedic Society; quality of life were evaluated according to SF-36 scale (36-item Short Form Health Survey, SF-36). RESULTS: All patients were followed up from 4 to 16 months with an average of 12 months. The JOA score of light, moderate, severe degeneration group were 12.1 +/- 1.5, 10.3 +/- 1.8, 7.3 +/- 1.0, respectively; and were respectively increased to 16.3 +/- 1.0, 15.3 +/- 1.4, 13.0 +/- 2.3 at the 3 months after operation. Postoperative JOA score showed the improvement rate of mid-long-term neurological level was light degeneration group (89.8%) > moderate degeneration group (76.6%) > severe degeneration group (58.8%). The results of preoperative SF-36 scale showed light degeneration group > moderate degeneration group > severe degeneration group; there was significant difference in comparison of two groups (P < 0.05 ). CONCLUSION: Cervical degeneration is an important pathologic basis and risk factor in traumatic cervical cord injury, and the degenerative degree will directly influence the injury degree and prognosis of neurological function, the clinical relationship between them should be sufficiently paid attention to.

Anterior migration of spinal cord after cervical corpectomy.

Posterior migration of spinal cord is a common complication of posterior cervical decompression, whereas anterior migration of spinal cord after anterior cervical decompression has not been reported previously. This report presents a case of anterior migration of spinal cord after cervical corpectomy. A 65-year-old male underwent a cervical corpectomy of the C4 and C5 for cervical spondylotic myelopathy. The postoperative MRI showed that spinal cord was decompressed. However, at 12 months postoperatively, the patient complained that improved gait aggravated again, and the MRI showed an anterior migration of the spinal cord at the level of the C4 and C5, and a compression of spinal cord at the level of caudal endplate of C3. Secondary surgery, laminaplasty of C3 and C4 was conducted. The postoperative MRI showed that the spinal canal increased at the C3 and C4 levels, and the spinal cord went through smoothly without sharp turning.

[Technique of bending rod reduction in situ for low lumbar burst fracture].

OBJECTIVE: To evaluate the efficacy and the feasibility of bending rod reduction in situ technique in treating low lumbar burst fracture. METHODS: From March 2007 to June 2009, 21 patients with low lumbar burst fracture were retrospectively analyzed, 11 cases were in L3,6 in L4 and 4 in L5. There were 16 males and 5 females, ranging in age from 25 to 59 year with an average of 37.9 years. According to ASIA classification, nerve function was level A in 2 cases, level B in 2, level C in 10, level D in 4 and level E in 3. Pedicle screws were implanted and bending rod reduction in situ technique was applied through posterior approach. Radiographic and neurological scores were compared before and after operation. RESULTS: All patients were followed up from 12 to 39 months with an average of 16.5 months. Radiographic examinations demonstrated that anterior height of fractured vertebral body was from 57.9% preoperatively to 94.1% postoperatively (P < 0.01 ); sagittal index was from 29.1 preoperatively to 0.240 postoperatively (P < 0.01). Spinal canal occupation ratio was from 49.6% preoperatively to 13.4% postoperatively (P < 0.01). Nerve function was level A in 2 cases,level B in 0, level C in 0, level D in 4 and level E in 15. CONCLUSION: Bending rod in situ technique could achieve 3-column reduction in 3-dimentionally at the same time, and reconstruct the stability of low lumbar.

[Effects of the electronic waste pollution on the levels of thyroid hormone and its receptor expression in the parturient woman and the newborn].

OBJECTIVE: The levels of thyroid hormones and its receptor expression in the parturient women and the newborns from an electronic waste dismantling region were investigated. METHODS: We detected the sera levels, including thyroid hormones FT3, FT4, TSH among the subjects from the exposed group (n=48) and the control group (n=45) by immuno radiometric assay (IRMA). The expression levels of TRalpha1, TRbeta1, TSHR mRNA in placentas and umbilical cords were detected by fluorscent quantitative real time PCR (FQ-PCR). The correlation were determined between the thyroid hormones levels in maternal, sera and in umbilical sera, and between the expression levels of its receptors mRNA in placentas and umbilical cords. RESULTS: (1) The FT4 levels of both maternal sera and umbilical cord sera in the exposed group were lower than those in the control (P < 0.05). However, increased the TSH levels in the exposed group were statistically significance compared to the control group (P < 0.05). (2) The TRalPHA1 and TRbeta1 mRNA levels both in placentas and umbilical cords in exposed group were lower than those in control group (P <0.05 and 0.01). However, the TSHR mRNA levels in the exposed group were statistically significance compared to the control group (P < 0.01). (3) The sera FT4 and TSH levels of parturient women were positively correlated with those of the newborns in both groups (P < 0.05 and 0.01). (4) The mRNA levels of TRalpha1, TRbeta1 and TSHR in placentas were positively correlated with those in umbilical cords in both groups (P < 0.01). CONCLUSION: The findings suggest that some environmental pollutants existing in e-waste dismantling region may affect the health of local parturient women and newborns, representing changes both in sera levels of thyroid hormones and in mRNA expression of its receptors.

[Endoscope-assisted thyroidectomy by chest approach with good cosmetic results].

OBJECTIVE: To explore the feasibility, safety, and cosmetic efficacy of endoscope-assisted thyroidectomy (EAT) by chest approach. METHODS: Fifty-one patients with single benign thyroid nodule < or = 4.0 cm in diameter, and without history of neck surgery or irradiation, 8 males and 43 females, aged 33.9 (18-64), underwent endoscope-assisted thyroidectomy by chest approach: a skin incision with the length of 4 cm was made in the chest, an endoscope was inserted, and subtotal or total thyroidectomy with the technique similar to that in conventional surgery was performed with naked eyes. RESULTS: Subtotal thyroidectomy was performed in 49 patients, and total excision of unilateral thyroid lobe plus isthmus lobectomy and contralateral partial lobectomy was performed on the other 2 patients. No patient was transferred to traditional surgery. Only one case showed palsy of recurrent nerve. Most patients expressed with the cosmetic results. CONCLUSION: EAT is a feasible and safe procedure with rather good cosmetic