Velamentous Cord Insertion: Interest of Antenatal Diagnosis and Review of the Literature

Velamentous insertion of the umbilical cord corresponds to the insertion of the cord directly on amniotic membranes. It is a rare situation whose frequency varies from 0.5% to 1.69% of single pregnancies. It must be diagnosed during the morphological ultrasound of the 2nd trimester, actively looking for the association with a vasa previa, due to the risk of fetal haemorrhagic threat. We report an antenatal diagnosis of velamentous cord insertion and its management with literature review.

针刀干预后颈椎病大鼠头夹肌成纤维细胞生长因子家族及其受体的表达

背景:针刀是治疗颈椎病的有效方法,临床疗效确切,但其关键分子机制尚不明晰。目的:观察针刀干预对颈椎病大鼠头夹肌成纤维细胞生长因子家族及其受体激酶插入域蛋白受体表达的影响,分析针刀治疗颈椎病的作用机制。方法:通过检索GEO数据库,获取符合该研究的芯片数据集GSE153761,采用生物信息学方法进行靶标初筛,然后进行动物实验。选取6月龄SPF级SD大鼠24只,随机均分为4组。模型组和针刀组大鼠采用动静力失衡性颈椎病造模方法制备颈椎病大鼠模型;假手术组不切断肌肉及韧带;针刀组造模成功后采用针刀干预,每周1次,共3次;并以正常大鼠作为对照。拍摄颈椎正侧位X射线片进行模型验证;旷场实验观察大鼠行为学变化;苏木精-伊红染色观察头夹肌病理结构;荧光定量PCR法和免疫组化法分别检测头夹肌成纤维细胞生长因子家族及其受体激酶插入域蛋白受体mRNA及蛋白的表达情况。结果与结论:①生物信息学结果表明成纤维细胞生长因子家族/激酶插入域蛋白受体是激活磷脂酰肌醇3-激酶/蛋白激酶B上游的重要信号轴。②造模后大鼠椎间隙变窄,椎体前后缘、关节突骨质增生。③旷场实验中,造模后大鼠总距离、平均速度降低(P<0.05),总休息时间延长(P<0.05);治疗后针刀组大鼠总距离、平均速度大于模型组(P<0.05),总休息时间短于模型组(P<0.05)。④头夹肌病理提示颈肌受损,而针刀可改善颈肌劳损。⑤与正常组比较,模型组大鼠头夹肌成纤维细胞生长因子7、成纤维细胞生长因子9、成纤维细胞生长因子10、成纤维细胞生长因子18和激酶插入域蛋白受体mRNA及蛋白表达均升高(P<0.05);与模型组比较,针刀组以上指标均降低(P<0.05)。⑥结果说明,针刀可能通过调节成纤维细胞生长因子7、成纤维细胞生长因子9、成纤维细胞生长因子10、成纤维细胞生长因子18及其受体激酶插入域蛋白受体的表达,修复劳损颈肌,从而改善椎间盘退变,这可能是针刀治疗颈椎病的关键靶点。

Genetic Analysis of a Small Grain Mutant Induced by T-DNA Insertion in Rice

[Objective] The aim of this study is to understand the genetic characteristics of a grain shape mutant and its possible role in genetic improvement of grain yield in rice. [Method] On the basis of the collection of T-DNA tag lines, the progeny of homozygous plants carrying T-DNA insertion were screened for mutants with mutated phenotypes. The genetic analysis of the mutant and test for the linkage between the mutated phenotype and the T-DNA insertion were carried out to determine its genetic characteristics. [Result] In the present study, a grain shape mutant induced by T-DNA insertion in rice was identified, which showed small grain. Genetic analysis of the mutant showed that the two types of phenotype, normal and small grain in the segregating populations derived from the T-DNA heterozygotes, fit the ratio of 3∶1. Test for Basta resistance showed that all the mutants were resistant while the normal plants segregated for resistant and susceptible by the ratio of 2∶1. The results indicated that the mutant phenotype cosegregated with Bar gene. The small grain mutant caused by T-DNA insertion was confirmed by PCR amplification aiming at T-DNA. [Conclusion] The grain shape mutant is useful for isolation of the tagged gene and genetic improvement in rice.

高分辨率小动物Micro Insert PET系统的模拟研究

在西门子Micro PET小动物成像系统中接入高分辨率的Insert探测器环,组成了Micro Insert PET系统,可以进一步提高小动物PET系统的图像分辨率。本文采用蒙特卡罗模拟软件GATE定义Focus-220小动物PET和Micro Insert两种系统,在同步仿真运算中,给出了三种类型的符合数据,即PET Scanner和PET Scanner之间的符合、PET Scanner和Insert之间的符合、Insert和Insert之间的符合。用滤波反投影算法重建了Na-22单点源模型、多点源模型、LZU模型的PET图像。其中,多点源模型的径向图像分辨率的仿真结果与美国华盛顿大学的Micro Insert实验数据,在忽略正电子射程、非线性效应项以及噪声等的贡献下,两者符合得很好。研究表明,使用Micro Insert系统能够将小动物PET系统的图像分辨率提高到亚毫米水平。

Needle Steering for Robot-Assisted Insertion into Soft Tissue:A Survey

Needle insertion is a common surgical procedure used in diagnosis and treatment.The needle steering technologies make continuous developments in theoretical and practical aspects along with the in-depth research on needle insertion.It is necessary to summarize and analyze the existing results to promote the future development of theories and applications of needle insertion.Thus,a survey of the state of the art of research is presented on algorithms of needle steering techniques,the surgical robots and devices.Based on the analysis of the needle insertion procedure,the concept of needle steering is defined as a kinematics problem,which is to place the needle at the target and avoid the obstacles.The needle steering techniques,including the artificial potential field method and the nonholonomic model,are introduced to control the needles for improving the accuracy.Based on the quasi-static thinking,the virtual spring model and the cantilever-beam model are developed to calculate the amount of needle deflection and generate the needle path.The phantoms instead of the real tissue are used to verify the models mentioned in most of the experimentations.For the desired needle trajectories,the image-guided robotic devices and some novel needles are presented to achieve the needle steering.Finally,the challenges are provided involving the controllability of the long flexible needle and the properties of soft tissue.The results and investigations can be used for further study on the precision and accuracy of needle insertion.

Position and complications of pedicle screw insertion with or without image-navigation techniques in the thoracolumbar spine:a meta-analysis of comparative studies

Computer-navigated pedicle screw insertion is applied to the thoracic and lumbar spine to attain high insertion accuracy and a low rate of screw-related complications.However,some in vivo and in vitro studies have shown that no advantages are gained with the use of navigation techniques compared to conventional techniques.Additionally,inconsistent conclusions have been drawn in various studies due to different population characteristics and methods used to assess the accuracy of screw placement.Moreover,it is not clear whether pedicle screw insertion with navigation techniques decreases the incidence of screw-related complications.Therefore,this study was sought to perform a meta-analysis of all available prospective evidence regarding pedicle screw insertion with or without navigation techniques in human thoracic and lumbar spine.We considered in vivo comparative studies that assessed the results of pedicle screw placement with or without navigation techniques.PubMed,Ovid MEDLINE and EMBASE databases were searched.Three published randomized controlled trials（RCTs） and nine retrospective comparative studies met the inclusion criteria.These studies included a total of 732 patients in whom 4,953 screws were inserted.In conclusion,accuracy of the position of grade I,II,III and IV screws and complication rate related to pedicle screw placement were significantly increased when navigation techniques were used in comparison to conventional techniques.Future research in this area should include RCTs with well-planned methodology to limit bias and report on validated,patient-based outcome measures.

Does flexible small-diameter colonoscope reduce insertion pain during colonoscopy?

AIM It is well known that colonoscopy can bedifficult due to abdominal pain induced duringcolonoscope insertion,if sedative agents are notgiven.Recently,an extra-flexible,small-diameter colonoscope(CF-SV,Olympus Inc.,Japan)was developed in order to improve safetyand comfort.The aim of this study was toaccess the usefulness of the CF-SV.METHODS One hundred patients undergoingsigmoidoscopy were recruited and colonoscopywas performed by one experiencedcolonoscopist.First,a routine-type colonoscope(CF-2301)was inserted into the colon withoutsedation.When the patient complained ofabdominal pain(even if mild),the scope wasnot advanced further and was withdrawn afterthe anatomic location of its tip was determinedfluoroscopically.Then,the CF-SV was inserteduntil it reached the cecun or the site whereabdominal pain occurred.Previous abdominalsurgery and abdominal disease were consideredas unfavorable factors(UF)and the relationshipbetween abdominal pain and UF,age and genderwere investigated.Furthermore,the colonicinsertion pressures in 36 patients with abdominalpain were measured with a force gauge.RESULTS Thirty-four cases(34%)felt no painwith the CF-2301 and successful pancolon-0scopies to the cecum were performed.Sixty-six cases(66%)complained of abdominal pain.The procedure was painless for 47% of men and24% of women,respectively.The CF-2301 scopefailed to reach the sigmoid-descending colon junctions in 59(89.4%)of the 66 patientscomplaining of abdominal pain.However,CF-SVreached proximal area in 94.9% of those whofailed with CF-2301.The median pressure forpain-inducing was 700 g/cm^2.CONCLUSION Unsedated patients with UFwere prone to complain of pain when thestandard-type CF-2301 scope was used.Thenewly developed extra-flexible CF-SV is usefulfor the aged and for those with UF or being proneto suffer from abdominal pain.Sedative agentsmay be unnecessary if this new type ofcolonoscope is used.

Prediction of Dynamic Cutting Force and Regenerative Chatter Stability in Inserted Cutters Milling

Currently, the modeling of cutting process mainly focuses on two aspects: one is the setup of the universal cutting force model that can be adapted to a broader cutting condition; the other is the setup of the exact cutting force model that can accurately reflect a true cutting process. However, there is little research on the prediction of chatter stablity in milling. Based on the generalized mathematical model of inserted cutters introduced by ENGIN, an improved geometrical, mechanical and dynamic model for the vast variety of inserted cutters widely used in engineering applications is presented, in which the average directional cutting force coefficients are obtained by means of a numerical approach, thus leading to an analytical determination of stability lobes diagram (SLD) on the axial depth of cut. A new kind of SLD on the radial depth of cut is also created to satisfy the special requirement of inserted cutter milling. The corresponding algorithms used for predicting cutting forces, vibrations, dimensional surface finish and stability lobes in inserted cutter milling under different cutting conditions are put forward. Thereafter, a dynamic simulation module of inserted cutter milling is implemented by using hybrid program of Matlab with Visual Basic. Verification tests are conducted on a vertical machine center for Aluminum alloy LC4 by using two different types of inserted cutters, and the effectiveness of the model and the algorithm is verified by the good agreement of simulation result with that of cutting tests under different cutting conditions. The proposed model can predict the cutting process accurately under a variety of cutting conditions, and a high efficient and chatter-free milling operation can be achieved by a cutting condition optimization in industry applications.

An Analysis of the Orthogonal Crank-rocking Lever Spatial Mechanism for the Weft Insertion in Rapier Looms

On the basis of the analysis of typical orthogonal crankrocking lever spatial mechanism for the weft insertion in rapier looms, the rules of the outputting lever motion and the mechanism pressure-angle variety are studied when the maximum swing angle of rocking lever and the length of outputting lever have different values, and the optimum parameters suitable for motion transmission can be chosen. At the same time some existing shortpoints of the mechanism are also pointed out.

Kinematic Modeling and Characteristic Analysis of Eccentric Conjugate Non-circular Gear & Crank-Rocker & Gears Train Weft Insertion Mechanism

A novel weft insertion mechanism named eccentric conjugate non-circular gear & crank-rocker & gears train weft insertion mechanism was proposed in order to better meet the requirements of rapier loom's weft insertion mechanism as well as reduce the manufacturing difficulty. Meanwhile, based on the working principle of this mechanism, kinematical mathematic models of this mechanism were established and an aided analysis and simulation software was compiled. The influences of eccentricity ratio, deformation coefficient, and other important parameters on the kinematics characteristics of this mechanism were analyzed by using the software. A group of preferable parameters which could meet the requirements of weft insertion technology were obtained by means of human-computer interactive optimization method. The maximum velocity, maximum acceleration, and variation of acceleration of this mechanism are smaller than those of the conjugate cam weft insertion mechanism applied on TT96 rapier loom under the conditions of the same unilateral total stroke of rapier head and the same rotary speed of loom spindle; meanwhile the other demands of weaving technology can be met by this novel weft insertion mechanism.

Angiotensin-converting Enzyme Gene Insertion/Deletion Polymorphism in Children with Henoch-Schonlein Purpua Nephritis

This study investigated the relationship between angiotensin-converting enzyme (ACE) gene insertion/deletion polymorphism and the occurrence, severity, prognosis of HSPN. The polymorphism of ACE gene in 103 HSPN cases and 100 healthy children was studied by using the polymerase chain reactions (PCR). Its relation to the clinical manifestation, pathological classification and prognosis of HSPN was analyzed accordingly. The results showed that: (1) there was a significantly higher frequency for DD genotype in HSPN children (P<0.01); (2) DD genotype was more frequently seen in HSPN children with gross hematuria and massive proteinuria (P<0.05), while DI genotype was more common in HSPN children group with renal insufficiency (P<0.05); (3) although mesangial proliferative lesion was most frequently observed in 21 biopsied HSPN children, and DD genotype frequency was still higher in children with severe pathology (Class Ⅲ Ⅳ); (4)II genotype was significantly frequent in HSPN children with complete remission in the follow-up of 32 HSPN children. It was concluded that the deletion allele of ACE gene might play a role, at least to some extent, in the occurrence, deterioration and progression in juvenile HSPN.

Development of Magnesium-Insertion Positive Electrode for Rechargeable Magnesium Batteries

Magnesium-based rechargeable batteries might be an interesting future alternative to lithium-based batteries. It is so far well known that Mg2+ ion insertion into ion-transfer hosts proceeds slowly compared with Li+, so it is necessary to realize fast Mg2+ transport in the host in addition to other requirements as practical cathode materials for magnesium batteries. Positive electrode materials based on inorganic transition-metal oxides, sulfides, and borides are the only ones used up to now to insert magnesium ions. In this paper, the available results of research on materials suitable as possible, for secondary magnesium batteries, are reviewed.

Augmented reality: The use of the PicoLinker smart glasses improves wire insertion under fluoroscopy

AIM To demonstrate the feasibility of the wearable smart glasses, Pico Linker, in guide wire insertion under fluoroscopic guidance. METHODS Under a fluoroscope, a surgeon inserted 3 mm guide wires into plastic femurs from the lateral cortex to the femoral head center while the surgeon did or did not wear Pico Linker, which are wearable smart glasses where the fluoroscopic video was displayed(10 guide wires each). RESULTS The tip apex distance, radiation exposure time and total insertion time were significantly shorter while wearing the Pico Linker smart glasses. CONCLUSION This study indicated that the Pico Linker smart glasses can improve accuracy, reduce radiation exposure time, and reduce total insertion time. This is due to the fact that the Pico Linker smart glasses enable surgeons to keep their eyes on the operation field.

Study of the Interface between Steel Insert and Aluminum Casting in EPC

The effective surface treatment method for steel insert composited with Al base metal by expendable pattern casting （EPC） process and the bonding interface between steel insert and Al base metal were investigated.It was found that Zn plating on steel insert was effective on improving the bonding property between steel insert and Al base metal in EPC process.Zn is thought to promote the formation of diffusion layer.But almost none content of Zn was observed in the boundary which had been plated on the steel insert.A diffusion layer consisting of Al,Si and Fe was formed at the insert/alloy interface and its hardness was higher than the steel insert as matter of course Al base metal.This layer turned out to be intermetallic compounds of Al-Si-Fe system.Higher pouring temperature promoted the diffusion of Fe into Al alloy,so Fe content in intermetallic layers increased at higher pouring temperature.The layer nearest to steel disappeared due to applied pressure.

A new insertion sequence for incremental Delaunay triangulation

Incremental algorithm is one of the most popular procedures for constructing Delaunay triangulations （DTs）. However, the point insertion sequence has a great impact on the amount of work needed for the construction of DTs. It affects the time for both point location and structure update, and hence the overall computational time of the triangulation algorithm. In this paper, a simple deterministic insertion sequence is proposed based on the breadth-first-search on a Kd-tree with some minor modifications for better performance. Using parent nodes as search-hints, the proposed insertion sequence proves to be faster and more stable than the Hilbert curve order and biased randomized insertion order （BRIO）, especially for non-uniform point distributions over a wide range of benchmark examples.

Analysis on the Characterization of the Twist Insertion Level and Its Effect of the Compact and Ring Spun Yarns

In this paper, the difference of the twist insertion levels of the compact and ring spun yarns of the same count is analyzed based on the relationship of the yarn twist factor to the twist angle and the bulk density. It is proposed that the relationship of the twist angle, twist level, and the yarn diameter should be synthetically considered when evaluating the twist insertion level of the compact yarn. The twist angle of the compact yarn is smaller than that of the ring yarn with the same twist insertion level. This results from the ordered fiber arrangement and compact structure of the compact yarn. Experiment was conducted to verify the conclusions. It is also discovered that the selection of the twist factor of the compact yarn, which can be usually lower than that of the ring yarn by 10%-15%, can be determined based on the yarn tensile strength.

Review on Li-insertion/extraction Mechanisms of LiFePO4 Cathode Materials

The work distills the main mechanisms during the lithium insertion/extraction of LiFePO_4 cathode materials. The "diffusion-controlled" and "phase-boundary controlled" mechanism are especially illustrated. Meanwhile, some recent observation and analyses by in-situ or in operando on the Li-insertion/extraction of LiFePO_4 are summarized and prospected.

Laparoscopic-assisted catheter insertion for continuous ambulatory peritoneal dialysis:A case report of simple technique for optimal placement

A 40-year-old male underwent tube placement surgery for continuous ambulatory peritoneal dialysis(CAPD).A2-cm skin incision was made,and the peritoneum was reflected enough to perform secure fixation.A swannecked,double-felted silicone CAPD catheter was inserted,and the felt cuff was sutured to the peritoneum to avoid postoperative leakage.An adequate gradient for tube fixation to the abdominal wall was confirmed.The CAPD tube was passed through a subcutaneous tunnel.Aeroperitoneum was induced to confirm that there was no air leakage from the sites of CAPD insertion.Two trocars were placed,and we confirmed that the CAPD tube led to the rectovesical pouch.Tip position was reliably observed laparoscopically.Optimal patency of the CAPD tube was confirmed during surgery.Placement of CAPD catheters by laparoscopic-assisted surgery has clear advantages in simplicity,safety,flexibility,and certainty.Laparoscopic technique should be considered the first choice for CAPD tube insertion.

DFT Investigation on the Insertion Reaction of an Isocyanide into the(Silyl)(silylene)molybdenum Si-C Bond

The chemistry of silylene-transition-metal complexes LnM（=SiR2）SiR3 is one of the attractive synthetic targets in organometallic chemistry for such complexes are key intermediates in many transition metal-catalyzed systems.In the present work,the novel insertion reactions of an isocyanide into the Cp＊Mo（CO）2（=SiMe2）（SiMe3） Si-C bond were investigated extensively by using the DFT method.The effective core potentials（ECP） with a double-ζ valence basis set（LanL2DZ） were employed for Mo and Si and the standard 6-31G basis set for all other atoms.Polarization functions[22] were added for Si（ζd = 0.262）,C（ζd = 0.8） and N（ζd = 0.8）.The effect of solvent was evaluated with the standard PCM model.Our calculations show that the two-step channel is energetically favorable,and the solvation mode has minor influence on the relative energies.

Focus on peripherally inserted central catheters in critically ill patients

Venous access devices are of pivotal importance for an increasing number of critically ill patients in a variety of disease states and in a variety of clinical settings(emergency, intensive care, surgery) and for different purposes(fluids or drugs infusions, parenteral nutrition, antibiotic therapy, hemodynamic monitoring, procedures of dialysis/apheresis). However, healthcare professionals are commonly worried about the possible consequences that may result using a central venous access device(CVAD)(mainly, bloodstream infections and thrombosis), both peripherally inserted central catheters(PICCs) and centrally inserted central catheters(CICCs). This review aims to discuss indications, insertion techniques, and care of PICCs in critically ill patients. PICCs have many advantages over standard CICCs. First of all, their insertion is easy and safe-due to their placement into peripheral veins of the armand the advantage of a central location of catheter tip suitable for all osmolarity and p H solutions. Using the ultrasound-guidance for the PICC insertion, the risk of hemothorax and pneumothorax can be avoided, as wellas the possibility of primary malposition is very low. PICC placement is also appropriate to avoid post-procedural hemorrhage in patients with an abnormal coagulative state who need a CVAD. Some limits previously ascribed to PICCs(i.e., low flow rates, difficult central venous pressure monitoring, lack of safety for radio-diagnostic procedures, single-lumen) have delayed their start up in the intensive care units as common practice. Though, the recent development of power-injectable PICCs overcomes these technical limitations and PICCs have started to spread in critical care settings. Two important take-home messages may be drawn from this review. First, the incidence of complications varies depending on venous accesses and healthcare professionals should be aware of the different clinical performance as well as of the different risks associated with each type of CVAD(CICCs or PICCs). Second, an inappropriate CVAD choice and, particularly, an inadequate insertion technique are relevant-and often not recognized-potential risk factors for complications in critically ill patients. We strongly believe that all healthcare professionals involved in the choice, insertion or management of CVADs in critically ill patients should know all potential risk factors of complications. This knowledge may minimize complications and guarantee longevity to the CVAD optimizing the risk/benefit ratio of CVAD insertion and use. Proper management of CVADs in critical care saves lines and lives. Much evidence from the medical literature and from the clinical practice supports our belief that, compared to CICCs, the so-called power-injectable peripherally inserted central catheters are a good alternative choice in critical care.