COTTON LEADS^(TM) 认证计划引发行业负责任生产的共鸣

COTTON LEADS^TM 认证计划由澳大利亚和美国棉花行业携手创立,并且是棉花基金会旗下的一个项目。其创始成员包括澳洲棉花协会、美国国家棉花总会、美国国际棉花协会和美国棉花公司。该计划旨在提高人们对负责任的棉花种植的认知度,并让人们了解其成员国的棉花种植者一直致力于持续改进。五大理念引领负责任生产截至目前,全球已经有超过232家机构和企业加入了该国际认证计划,其中,中国有63家企业加入该计划,

Numerical simulation of soldered joints and reliability analysis of PLCC components with J-shape leads

This paper deals with a study on SnPb and lead-free soldered joint reliability of PLCC devices with different lead counts under three kinds of temperature cycle profiles, which is based on non-linear finite element method. By analyzing the stress of soldered joints, it is found that the largest stress is at the area between the soldered joints and the leads, and analysis results indicate that the yon Mises stress at the location slightly increases with the increase of lead counts. For PLCC with 84 leads the soldered joints was modeled for three typical loading （273 -398 K, 218 -398 K and 198 -398 K） in order to study the influence of acceleration factors on the reliability of soldered joints. And the estimation of equivalent plastic strain of three different lead-free solder alloys （ Sn3.8AG0. 7Cu, Sn3.5Ag and Sn37Pb ） was also carried out.

Novel Metal-organic Framework Compound Pb(C_5H_4NCOO)_2 Showing One-dimensional Channel Defined as Four Leads and Four Nicotinic Acids

A novel metal-organic framework（MOF） compound of Pb（C5H4NCOO）2 was hydrothermally synthesized and structurally determined by X-ray single-crystal diffraction. The data of unit cell： orthorhombic space group Pccn, a=1.0325（2） nm, b=1.3597（3） nm, c=0.8499（2） nm, V=1.1931（4） nm^3, Z=4, Dc=2.513 g/cm^3, R1=0.047 were obtained on the basis of 1365 reflections with Fo〉2σ（Fo）. PbN2O6 polyhedron adopts the distorted cubic configuration which is assigned to the holodirected geometry. These PbN2O6 polyhedra can form the zigzag chain by edge-sharing mode along（001） direction. Pb atom is connected by six nicotinic acid molecules, leading neutral 3D metal-organic framework with a channel defined by four Pb atoms and four nicotinic acid molecules.

Influence of heat loss through probe electrical leads on thermal conductivity measurement with TPS method

The transient plane source(TPS)method is developed recently to measure the thermal conductivity of materials.In the measurement,the heating power is influenced by the heat which is transferred via the probe electrical leads.This fact further influences the measurement accuracy of thermal conductivity.To solve this problem,the influence of heat loss through the electrical leads on the heating power is studied theoretically.The mathematical formula of heat loss is deduced,and the corresponding correction model is presented.A series of measurement experiments on different materials have been conducted by using the hot disk thermal constant analyzer.The results show that the influence of the heat loss on the measurement is sensitive to different test materials and probes with different sizes.When the thermal conductivity of the material is greater than 0.2 W/(m·K),the influence of the heat loss is less than 0.16%,which can be ignored.As to the lower thermal conductivity materials,it is necessary to compensate the heat loss through the electrical leads,and the accuracy of thermal conductivity measurement can be effectively improved.

Exploring of drug leads from diversity-oriented Michael-acceptor library derived from natural products

A potential strategy for drug lead identification and in-active natural products re-discovery is elaborated.Starting from fifteen structurally diverse natural products,a focused library featured by Michael acceptors is constructed with IBX mediated oxidation.Biological assay on five tumor cell lines indicates that four Michael acceptors,8a,11a,12a,14a,are with improved cytotoxicity(3-10 folds more potent than the parent compounds),which merit further investigations.Further thiol-sensitive assay of the active hit 8a revealed that it was an irreversible Michael acceptor.The results suggest that the strategy is not only effective and relatively high discovery rate(28%),but also resource saving.

Multi-targeting cytotoxic drug leads from mushrooms

Due to genetic and epigenetic mechanisms, cancer have become a resistant disease and there is a need for new molecules having multiple targeting action that promotes apoptosis. Phytomolecules having multiple targeting anticancer activity are in high demand and there is less documentation or information available on these metabolites. It is evident that mushrooms are became the store houses of new anticancer molecules and mushrooms like Agaricus blazei, Antrodia camphorate, Albatrellus confluens, Bolteus badius, Cordyceps militaris, Clitocybe maxima, Funalia trogii, Grifola frondosa, and Inocybe umbrinella, are some of the medicinal mushrooms reported for their cytotoxic activity. Cytotoxic molecules like lentinan, grifolin, illudin-S, psilocybin, ganoderic acid, theanine, and hispolon, have been isolated from various mushroom species. However, studies have been limited only to in vitro cytotoxic mechanisms and very few trials have been conducted to prove the clinical efficacy of these drug leads. Hence, the current review focuses on new anticancer metabolites isolated from various mushrooms having multiple targeting mechanisms in cancer. However, an extensive research is needed to define the biosynthesis and clinical mechanism of these multiple acting metabolites. This review provides a platform for researchers new anticancer drugs and to bring out potent multiple acting anticancer newer drugs.

Pretreatment of caffeine leads to partial neuroprotection in MPTP model of Parkinson＇s disease

Parkinson＇s disease （PD） is disorder affecting more than a common neurodegenerative 1% people above 60 years of age worldwide, manifesting as the impaired motor function such as tremors, rigidity, akinesia/bradykinesia and postural inefficiency with a reduced life expectancy （Dorsey et al., 2007）. PD is believed to be the end result of the progressive death of dopaminergic neurons in the substantia nigra pars compacta （SNc）.

Safety, Handling and Electrical Performances of Bradycardia Leads in Acute Conditions: Results from the FINE Registry

Background: Beflex is an active fixation atrial and ventricular lead with a retractable screw;X-Fine is a passive fixation ventricular lead. These two bradycardia lead models were evaluated in the FINE study, an observational prospective trial conducted in France and Spain. Methods: Patients enlisted for pacemaker or defibrillator implants were enrolled. The primary objective was to assess acute dislodgement rates at the 3-month follow-up visit. Safety and electrical performances of the leads were assessed in acute conditions at implant and at the follow-up visit up to three months later. A handling questionnaire was submitted to implanting investigators immediately after implant. Results: A total of 2254 patients were enrolled in 95 centers;investigators implanted 1153 active atrial leads, mainly in the right atrium;1021 active right ventricular leads, mainly in the septum and 712 passive right ventricular leads, mainly in the apex. After a mean follow-up of 54.9 ± 37.6 days, dislodgement rates were 1.0% and 1.6% for atrial and ventricular active, and 3.2% for ventricular passive leads. No unexpected adverse reactions were observed during the course of the study and the electrical performances at implant and follow-up visits remained within normal ranges. Overall, most investigators (84%) rated leads’ handling as superior (better or best) to what observed with other bradycardia leads. Conclusion: Different bradycardia leads showed a dislodgement rate of 1.0% and 1.6% for atrial and ventricular active leads, and 3.2% for ventricular passive leads, at 3-month follow-up. Acute safety and electrical performances were within expected ranges and very good handling performances were observed.

Novel anti-AD dimeric leads:from relieving symptoms to modifying diseases via multi-targets

Alzheimer disease(AD) has now become the most common brain disorder among the older population. In addition, the currently existing therapeutics only offer temporary symptomatic relieves. Therefore, further research and development of more efficacious and disease-modifying agents for the prevention, treatment and restoration of AD will have tremendous value from both scientific, and economic standpoints. Over the past few years, our series of studies have identified several highly promising anti-AD dimeric leads, with disease-modifying potentials. In this presentation, the latest progress on the neuroprotective and disease modifying effects and the underlying mechanisms of those candidates will be comprehensively illustrated and discussed.

Bipolar Leads for Prevention of Phrenic Nerve Stimulation: Results from the ORPHEE Observational Study

Background: Up to one in three patients implanted with a cardiac resynchronization therapy-defibrillator (CRT-D) device experience phrenic nerve stimulation (PNS). Quadripolar leads are effective at reducing PNS, but compared to standard bipolar leads they have limitations related to maneuverability and high pacing thresholds. The ability of standard bipolar leads to overcome PNS is explored here. Methods: The French multicenter, observational study ORPHEE enrolled 90 CRT-D-eligible patients. Detection of PNS took place after satisfactory positioning of the LV bipolar lead (stable pacing threshold - LV ring, LV tip - RV ring and LV ring - RV coil) could prevent PNS from occurring in at least 90% of patients. Results: In 80 evaluable patients, PNS was reported in 12 patients (15%). Reprogramming overcame PNS in 10 patients: LV ring - RV coil in 8 patients;LV tip - LV ring in 1;and LV tip- RV ring in 1. As PNS was avoided in 78 of 80 patients (97.5%), the primary endpoint was significant (97.5% vs. 90%, p = 0.01). Conclusion: During CRT-D implantation, PNS occurred in 15% of patients. In most (97.5%) implanted patients, PNS could be avoided by vector reprogramming using a bipolar LV lead. For patients whose coronary sinus anatomy precludes the implantation of multi-electrode leads, bipolar leads are a suitable, reliable alternative.

Generating and reversing spin accumulation by temperature gradient in a quantum dot attached to ferromagnetic leads

We propose to generate and reverse the spin accumulation in a quantum dot （QD） by using the temperature difference between the two ferromagnetic leads connected to the dot. The electrons are driven purely by the temperature gradient in the absence of an electric bias and a magnetic field. In the Coulomb blockade regime, we find two ways to reverse the spin accumulation. One is by adjusting the QD energy level with a fixed temperature gradient, and the other is by reversing the temperature gradient direction for a fixed value of the dot level. The spin accumulation in the QD can be enhanced by the magnitudes of both the leads＇ spin polarization and the asymmetry of the dot-lead coupling strengths. The present device is quite simple, and the obtained results may have practical usage in spintronics or quantum information processing.

Electronic transport through a quantum ring coupled to ferromagnetic leads

We study the spin-dependent transport through a one-dimensional quantum ring with taking both the Rashba spin-orbit coupling （RSOC） and ferromagnetic leads into consideration. The linear conductance is obtained by the Green＇s function method. We find that due to the quantum interference effect arising from the RSOC-induced spin precession phase and the difference in travelling phase between the two arms of the ring, the conductance becomes spin-polarized even in the antiparallel magnetic configuration of the two leads, which is different from the case in single conduction channel system. The linear conductance, the spin polarization and the tunnel magnetoresistance are periodic functions of the two phases, and can be efficiently tuned by the structure parameters.

Spin-flip process through double quantum dots coupled to two half-metallic ferromagnetic leads

We investigate the spin-flip process through double quantum dots coupled to two half-metallic ferromagnetic leads in series. By means of the slave-boson mean-field approximation, we calculate the density of states in the Kondo regime for two different configurations of the leads. It is found that the transport shows some remarkable properties depending on the spin-flip strength. These effects may be useful in exploiting the role of electronic correlation in spintronics.

R&D on Resistive Heat Exchangers for HTS High Rated Current Leads

The HTS current leads of superconducting magnets for large scale fusion devices and high energy particle colliders can reduce the power consumption for cooling by 2/3 compared with conventional leads. The resistive sections of high-rated current leads are usually made of a heat exchanger cooled by gas flow. The supply of the cooling mass flow incurs more than 90% of the cooling cost for the HTS leads. The mass flow rate requirement depends not only on the length and material of the resistive heat exchanger, but also on the heat transfer coefficient and HEX surface, the joint resistance at the cold end of a sheet-stack HEX with a larger specific presented in the paper. The test results of efficiency can be achieved. and its cooling approach. The design and operation surface and a much smaller hydraulic diameter are an HTS lead optimized for 8 kA show that a 98.4%

Bipolar Esophageal Electrocardiography by Using Standard Limb Leads

The ear-xiphisternum distance (EXD, the distance from the low edge of the ear to the xiphisternal basis in supine position) was used as a reference value for esophageal catheter insertion. ECGs recorded in the esophagus with bipolar electrocardiography using standard limb lead (ESLL) and conventional unipolar lead (ECUL) were compared. 112 patients with sinus rhythm and 76 patients during paroxysmal supraventricular tachycardia (PSVT) whose P-wave and QRS complex did not overlap were studied. The results suggested that in sinus rhythm the amplitude of the P-wave in ESLL was larger and the T-wave was smaller than in ECUL. During PSVT, the P-wave was much clear and higher in each lead of ESLL than that in ECUL. The ideal range of esophageal ECG recording was situated between the end of EXD and 6. 5 cm proximal to it.

Externalized conductors and insulation failure in Biotronik defibrillator leads: History repeating or a false alarm?

Conductor externalization and insulation failure are frequent complications with the recalled St. Jude Medical Riata implantable cardioverter-defibrillator(ICD) leads. Conductor externalization is a "unique" failure mechanism: Cables externalize through the insulation("inside-out" abrasion) and appear outside the lead body. Recently, single reports described a similar failure also for Biotronik leads. Moreover, some studies reported a high rate of electrical dysfunction(not only insulation failure) with Biotronik Linox leads and a reduced survival rate in comparison with the competitors. In this paper we describe the case of a patient with a Biotronik Kentrox ICD lead presenting with signs of insulation failure and conductor externalization at fluoroscopy. Due to the high risk of extraction we decided to implant a new lead, abandoning the damaged one; lead reimplant was uneventful. Subsequently, we review currently available literature about Biotronik Kentrox and Linox ICD lead failure and in particular externalized conductors. Some single-center studies and a nonprospective registry reported a survival rate between 88% and 91% at 5 years for Linox leads, significantly worse than that of other manufacturers. However, the preliminary results of two ongoing multicenter, prospective registries(GALAXY and CELESTIAL) showed 96% survival rate at 5 years after implant, well within industry standards. Ongoing data collection is needed to confirm longer-term performance of this family of ICD leads.

Implantation of Lumenless Pacing Leads at the Inter-atrial Septum and Right Ventricular Outflow Tract with Deflectable Catheter-sheath

Current permanent right ventricular and right atrial endocardial pacing leads are implanted utilizing a central lumen stylet. Right ventricular apex pacing initiates an abnormal asynchronous electrical activation pattern, which results in asynchronous ventricular contraction and relaxation. When pacing from right atrial appendage, the conduction time between two atria will be prolonged, which results in heterogeneity for both depolarization and repolarization. Six patients with Class Ⅰ indication for permanent pacing were implanted with either single chamber or dual chamber pacemaker. The SelectSecure 3830 4-French （Fr） lumenless lead and the SelectSite C304 8.5-Fr steerable catheter-sheath （Medtronic Inc., USA） were used. Pre-selected pacing sites included inter-atrial septum and right ventricular outflow tract, which were defined by ECG and fluoroscopic criteria. All the implanting procedures were successful without complication. Testing results （mean atrial pacing threshold： 0.87 V; mean P wave amplitude： 2.28 mV; mean ventricular pacing threshold： 0.53V; mean R wave amplitude： 8.75 mV） were satisfactory. It is concluded that implantation of a 4-Fr lumenless pacing lead by using a streerable catheter-sheath to achieve inter-atrial septum or right ventricular outflow tract pacing is safe and feasible.

Hemothorax induced by cardiac perforation resulting from two active screw-in leads: A case report

We describe the case of a 77-year-old female who underwent dual-chamber permanent pacemaker implantation using two active screw-in leads for complete atrioventricular block. The two active screw-in leads perforated the atrial and ventricular walls causing cardiac tamponade and a left hemothorax associated with ventricular perforation. An emergency sternotomy was performed to facilitate drainage and hemostasis. Although hemothorax due to pacing lead perforation is very rare, such a possibility should always be considered.

A short overview of the lead iodide residue impact and regulation strategies in perovskite solar cells

Lead iodide(PbI2) is a vital raw material for preparing perovskite solar cells(PSCs),and it not only takes part in forming the light absorption layer but also remains in the grain boundary as a passivator.In other words,the PbI2 content in the precursor and as formed film will affect the efficiency and stability of the PSCs.With moderate residual PbI2,it passivates the bulk/surface defects of perovskite,reduces the interfacial recombination,promotes the perovskite stability,minimizes the device hysteresis,and so on.Deficient PbI2 residue will reduce the interfacial passivation effect and device performance.In addition to facilitating the non-radiative recombination,over PbI2 residue can also lead to electronic insulation in the grain boundary and deteriorate the device performance.However,the impact and regulation of PbI2 residue on the device performance and stability is still not fully understood.Herein,a comprehensive and detailed review is presented by discussing the PbI2 residue impact and its regulation strategies(i.e., elimination,facilitation and conversion of the residue PbI2) to manipulate the PbI2 content,distribution and forms.Finally,we also show future outlooks in this field,with an aim to help further the progression of high-efficiency and stable PSCs.

Feasibility of MRI in Patients with Non-Pacemaker/Defibrillator Metallic Devices and Abandoned Leads

Objective: To evaluate feasibility of MRI in patients with non-pacemaker (PM)/Implantable cardioverter defibrillator (ICD) metallic devices and abandoned leads. Background: Relative safety of MRI performed using specified protocol has been established in MR non-conditional PM/ICDs. With limited safety data, many non-PM/ICD metallic devices and abandoned leads continue to be a contraindication for MRI. Methods: We retrospectively analyzed consecutive patients with extra-cardiac devices, non-programmable cardiac devices, and abandoned leads, who underwent MRI (GE 1.5 Tesla, WI) at a single tertiary care center over a span of 13 years. Scan protocol was designed to maintain specific absorption rate (SAR) < 4.0 W/kg and scan time < 60 minutes. Results: The cohort comprised 127 MRI exams representing 94 patients, with 13 patients having two or more scans. The devices consisted of: 23 vagal nerve stimulators (VNS), 22 implantable loop recorders, 16 spinal stimulators, 5 peripheral nerve stimulators, 3 bladder stimulators, 2 deep brain stimulators, 1 gastric stimulator, 1 bone stimulator, 1 WATCHMAN device, 22 abandoned PM/lCD leads and 1 VNS lead. There was no immediate (peri-MRI exam) morbidity or mortality. Patients did not report any discomfort, palpitations, heating, or sensation of device migration during the exam. Local follow-up data was available in 65% (100% for thoracic imaging) with a mean of 190 ± 475 days (median 13 days). No device malfunction was reported during follow-up. Conclusions: With appropriate precautions, MRI is feasible in patients with extracardiac devices, nonprogrammable cardiac devices, and abandoned leads.