Fabrication and characterisation of periodically poled lithium niobate waveguide using femtosecond laser pulses

We present in this letter the fabrication and characterization of thermally stable type II waveguides in Z-cut periodically poled lithium niobate crystals. The waveguides were fabricated by using a femtosecond laser and were utilized for second harmonic generation. Our experiments have shown that a quasiphase matching wavelength of 1548.2nm, a tuning bandwidth of 2nm, and a tuning temperature range of 150.4±1.6°C can be achieved

Advances in genetic factors of adolescent idiopathic scoliosis: a bibliometric analysis

ObjectiveThis study offers a bibliometric analysis of the current situation, hotspots, and cutting-edge domains of genetic factors of adolescent idiopathic scoliosis (AIS).MethodsAll publications related to genetic factors of AIS from January 1, 1992, to February 28, 2023, were searched from the Web of Science. CiteSpace software was employed for bibliometric analysis, collecting information about countries, institutions, authors, journals, and keywords of each article.ResultsA cumulative number of 308 articles have been ascertained. Since 2006, publications relating to genetic factors of AIS have significantly increased. China leads in both productivity and influence in this area, with the Chinese Academy of Medical Sciences being the most productive institution. The most prolific scholars in this field are Y. Qiu and Z. Z. Zhu. The publications that contributed the most were from Spine and European Spine Journal. The most prominent keywords in the genetic factors of AIS were “fibrillin gene”, “menarche”, “calmodulin”, “estrogen receptor gene”, “linkage analysis”, “disc degeneration”, “bone mineral density”, “melatonin signaling dysfunction”, “collagen gene”, “mesenchymal stem cell”, “LBX1”, “promoter polymorphism”, “Bone formation”, “cerebrospinal fluid flow” and “extracellular matrix”.ConclusionThis analysis provides the frontiers and trends of genetic factors in AIS, including relevant research, partners, institutions and countries

Posterior hemivertebra resection without internal fixation in the treatment of congenital scoliosis in very young children

ObjectiveTo retrospectively analyze the feasibility and efficacy of posterior hemivertebra resection without internal fixation in the treatment of congenital scoliosis in very young children.MethodsSixteen cases of very young children with congenital scoliosis treated at our hospital from April 2000 to July 2019 were collected, including 8 cases of each sex, all of whom had type I/III congenital scoliosis and were operated on at a median (interquartile range) of 9.00 (7.75) months (range, 0.5–48 months) of age. All cases underwent posterior hemivertebra resection without internal fixation and wore orthopedic braces or plaster undershirts for more than six months after surgery, with a mean follow-up of 94.31 ± 65.63 months (range, 36–222 months).ResultsCoronal plane: the preoperative Cobb angle for the segmental curve was 39.50 ± 9.70° compared to postoperative (19.19 ± 8.56°) and last follow-up (14.94 ± 12.11°) (both P < 0.01); the preoperative Cobb angle for the main curve was 34.19 ± 14.34° compared to postoperative (17.00 ± 11.70°) and last follow-up (17.56 ± 16.31°) (both P < 0.01); the preoperative Cobb angle of the proximal compensated curve was 14.88 ± 9.62° compared to postoperative (7.88 ± 4.66°) and last follow-up (8.38 ± 8.36°) (both P < 0.05); and the preoperative Cobb angle of the distal compensated curve was 13.50° (10.50°) (range, 4°–30°) compared with postoperative 4.50° (9.25°) (range, −3° to 25°) and final follow-up 5.50° (9.50°) (range, −3° to 33°) (both P < 0.01). Sagittal plane: the difference in the preoperative Cobb angle was 10.00° (14.00°) (range, −31° to 41°) for segmental kyphosis compared to postoperative 14.00° (24.50°) (range, −6° to 46°) and last follow-up 17.00° (22.55°) (range, −40° to 56°), and these were not statistically significant (both P > 0.05). There was a tendency for the thoracolumbar kyphosis to worsen and the lumbosacral kyphosis to improve during the follow-up period.ConclusionPosterior hemivertebra resection without internal fixation is a feasible treatment for type I/III congenital scoliosis in very young children, but the correction of the sagittal deformity of the thoracolumbar spine is not satisfactory, and postoperative external fixation may require further improvement

Recent Advances in Lignocellulose-Based Monomers and Their Polymerization

Replacing fossil-based polymers with renewable bio-based polymers is one of the most promising ways to solve the environmental issues and climate change we human beings are facing. The production of new lignocellulose-based polymers involves five steps, including (1) fractionation of lignocellulose into cellulose, hemicellulose, and lignin; (2) depolymerization of the fractionated cellulose, hemicellulose, and lignin into carbohydrates and aromatic compounds; (3) catalytic or thermal conversion of the depolymerized carbohydrates and aromatic compounds to platform chemicals; (4) further conversion of the platform chemicals to the desired bio-based monomers; (5) polymerization of the above monomers to bio-based polymers by suitable polymerization methods. This review article will focus on the progress of bio-based monomers derived from lignocellulose, in particular the preparation of bio-based monomers from 5-hydroxymethylfurfural (5-HMF) and vanillin, and their polymerization methods. The latest research progress and application scenarios of related bio-based polymeric materials will be also discussed, as well as future trends in bio-based polymers

Recent Advances in Lignocellulose-Based Monomers and Their Polymerization

Replacing fossil-based polymers with renewable bio-based polymers is one of the most promising ways to solve the environmental issues and climate change we human beings are facing. The production of new lignocellulose-based polymers involves five steps, including (1) fractionation of lignocellulose into cellulose, hemicellulose, and lignin; (2) depolymerization of the fractionated cellulose, hemicellulose, and lignin into carbohydrates and aromatic compounds; (3) catalytic or thermal conversion of the depolymerized carbohydrates and aromatic compounds to platform chemicals; (4) further conversion of the platform chemicals to the desired bio-based monomers; (5) polymerization of the above monomers to bio-based polymers by suitable polymerization methods. This review article will focus on the progress of bio-based monomers derived from lignocellulose, in particular the preparation of bio-based monomers from 5-hydroxymethylfurfural (5-HMF) and vanillin, and their polymerization methods. The latest research progress and application scenarios of related bio-based polymeric materials will be also discussed, as well as future trends in bio-based polymers

Aberration of p73 Promoter Methylation in Chondrosarcoma

p73 is a tumor-suppressor gene with significant homology to p53. Abnormal promoter methylation of p73 is present in different types of cancer. However, the promoter methylation status of p73 in chondrosarcoma (CS) is unknown. p73 promoter methylation status was evaluated by quantitative polymerase chain reaction (PCR), p73 protein expression by western blot, and the relationship between p73 methylation and clinical data was analyzed. In 42 tumor tissues with CS, we found that three cases (7%) maintained methylation levels between 51% and 75%, and 39 cases (93%) had levels between 76% and 100%. p73 methylation level was significantly (p<0.05) positively associated with histological grade. Loss of p73 protein expression was correlated with high methylation of the p73 promoter; p73 expression was restored after exposure to a demethylating drug. p73 is epigenetically silenced in CS due to promoter methylation, which suggests the utility of p73 methylation as a biomarker

Scatter plot of age and volume of testis on the hydrocele side.

Scatter plot of age and volume of testis on the hydrocele side.</p

Spearman’s rank correlation analysis with volume of the testis in 138 patients.

Spearman’s rank correlation analysis with volume of the testis in 138 patients.</p

RESEARCH ON PERFORMANCE OPTIMIZATION METHOD OF MECHANICAL PARTS BASED ON CAD/CAE INTEGRATION

Aiming at the problems of low efficiency, long cycle and difficulty in quality assurance in product design faced by most manufacturing enterprises, performing research on parameterized CAD and CAE technology, as well as the data transmission between software CAD and CAE, a general design method for optimizing the performance parameters of mechanical parts based on CAD/CAE integration was proposed. This method took Visual Studio as the platform, used APDL and C++ language for redeveloped ANSYS and Solid Works respectively, and developed a digital design system of mechanical parts based on CAD/CAE integration. After changing the parameter value, the system solves the finite element solution automatically and quickly, the solution results are automatically output to the specified path, and the solution results are automatically opened and locked. Taking the design of inner ring of driven plate for example, the three-dimensional（3 D） model and solution results were quickly obtained by this method. The research results show that this method is feasible and universal

Comparison of the testes’ parameters on the hydrocele and normal sides in 138 patients.

Comparison of the testes’ parameters on the hydrocele and normal sides in 138 patients.</p