bluuebunny/crossref_metadata_2025 huggingface dataset:
Scanning HEPA Filters with Photometers
Authors: McDonald Bruce
Published: November 2020

High-efficiency particulate air (HEPA) filters and ultra low penetration air (ULPA) filters such as those used in cleanrooms and clean benches are frequently scanned or probed for leaks. Historically, filters were scanned with a light-scattering photometer that measures the light scattered from many particles simultaneously. While particle counting methods have been introduced, the photometer methods are still used in many cases. There has not been a documented basis for the scanning speed when using photometers. The photometer response time and the time that the probe is over a leak affects the magnitude of the meter response. This paper sets forth a model for the photometer response characteristics. Photometer response to a leak while scanning is modeled as a simple exponential process. The model is verified with experimental data. Time constants for the experimental system were determined. The effect of the response time on the ability to detect leaks is discussed. Methods to compenstate for the loss of sensitivity during scanning are presented.
Enhanced Multiaxis Vibration Control Using a Robust Generalized Inverse System Matrix
Authors: Fletcher Jeffrey , Vold Håvard , Hansen Mark
Published: November 2020

Multiaxis vibration control as a means to recreate service stress in the laboratory has achieved a great deal of success in the last decade. While initial applications centered around components and assemblies requiring a relatively few number of inputs (1 to 4), current applications such as a full-vehicle simulation may require 12 or more exciters. The complexity of the control process required to accurately reproduce the time history response for a full-vehicle simulation often requires that an expert operator intervene to coax the system into convergence. The time spent developing a control signal for a simulation test is costly in terms of both program timing and equipment wear and tear. Often compromises must be made due to the inability of the control system to create a fully accurate response given the available time and resources. This paper discusses the development and application of a new robust control technique that decreases operator interaction while improving control accuracy.
The ESS Muddle: Physics vs. Relics
Authors: Caruso Hank
Published: November 2020

This paper examines the history and evolution of environmental stress screening (ESS) to show how uncoordinated initiatives from each military service contributed to the current state of array in the ESS community. The lack of a common vision for ESS is examined as a continuing handicap in efforts to integrate ESS more fully into the hardware development process. Common areas of confusion regarding effective ESS procedures and facilities are discussed, including: temperature air change rate vs. hardware thermal response; the number of vibration axes needed; simultaneous vibration in combined axes vs. sequential vibration in each; and pneumatic vs. electrodynamic vibration facilities. A "checklist" of considerations to apply in developing a successful ESS program is presented. The June, 1994, DoD initiative regarding possible elimination or replacement of military specifications and standards with commercial standards is reviewed with respect to ESS.
On-Site Prediction of Overstress in an Aircraft Munitions Carrier
Authors: Yowell Lindsay , Connon William
Published: November 2020

Vibration and strain data were measured on a modified munitions trailer to ensure that the design strength criteria had not been exceeded. These data were used in conjunction with a computer model to determine if the stress levels were sufficiently low to allow adequate fatigue life without further modification to the trailer. By combining standard data verification techniques with a stress prediction technique, data from a number of channels were reviewed at the test site to determine the severity of measured levels. This information was used to control the test process.
Lower Detection Limit of Aerosol Particle Counters
Authors: Liu Benjamin , Yoo Seong-Ho , Chae Seung-Ki
Published: November 2020

Aerosol particle counters based on light-scattering have a broad range of applications including cleanroom monitoring, air pollution research, and pharmaceutical studies. Each application may deal with particle materials having various refractive indices. The effect of the particle refractive index on the lower detection limit of aerosol particle counters was investigated using the Mie theory. Counting efficiency measurements were made to verify the theoretical results. Measurements were performed with PSL (polystyrene latex), silicon, silicon nitride, and silicon dioxide particles. Two commercial aerosol counters and a condensation nucleus counter were used in the study.

The theoretical study showed that both the real and the imaginary parts of the particle refractive index play an important role in the lower detection limit of an aerosol counter. For transparent particles, as the absolute difference between the particle and medium refractive index increases, the lower detection limit of a counter is decreased. Light-absorbing particles generally showed a smaller lower detection limit than transparent particles. Experimental measurements agree well with the theoretical results. Among the test particles used, silicon had the largest refractive index, followed by silicon nitride, PSL, and silicon dioxide. The lower detection limit of the counters studied showed a decreasing trend with an increasing real part of the refractive index as the particle material is changed from silicon dioxide to PSL, silicon nitride, and silicon. The difference between the theoretically calculated and experimentally determined lower detection limits were found to be less than 10 percent.
Particle Fallout in a Class 100,000 High-Bay Aerospace Cleanroom
Authors: Peters Sally
Published: November 2020

Cleanrooms are certified to a particular class by measuring the airborne particle count. However, the aerospace industry is generally more interested in particles larger than those detected by an airborne particle counter. The amount of large particles in a cleanroom is generally measured by use of fallout plates. The Boeing Company has utilized a Class 100,000 high-bay cleanroom for processing aerospace hardware. The cleanroom has consistently met Class 100,000 airborne particulate requirements, but larger particle fallout has varied substantially in the room. Approximately 4 yr of fallout data have been collected for this cleanroom. By tracking fallout, it was possible to detect actions that either positively or adversely affected the fallout rate. the fallout data, the variables affecting the fallout rate, the type of fallout, and the measurement methodology are presented.
Static and Dynamic Calibration of Pressure Transducers at Elevated Temperatures
Authors: Banaszak David , Camden Michael
Published: November 2020

The Air Force conducts tests requiring measurement of high dynamic pressures in high-temperature environments. Such tests require measurement of dynamic pressures created by jet engines, turbulent air-flow along hot areas of aircraft structures, and acoustic levels in Air Force test chambers such as acoustic chambers, wind tunnels, and engine test stands. Several commercial industries also have requirements for high-temperature dynamic measurements.

To address these Air Force needs for dynamic pressure measurements at high temperatures, the Structures Division of the Flight Dynamics Directorate of the Wright Laboratory evaluated dynamic pressure transducers for use in extreme acoustic and thermal environments. Transducer manufacturers were surveyed and three off-the-shelf pressure transducers capable of measuring dynamic pressures at extreme environments were identified. The first model measures up to 194 dB(A) and operates up to 260°C (500°F). This model has an extended operating temperature up to 1649°C (3000 °F) when used with a water-cooled jacket. The second model is an air-cooled transducer advertised to operate up to 593°C (1100°F). The third model is a water-cooled transducer advertised to operate up to 2802°C (5075 °F). Two of the models have low sensitivity and thus require more output amplification. These two models are also larger and require larger mounting holes. The transducers were evaluated at various static pressures, acoustic levels, and temperatures. This paper describes the procedures used to calibrate these transducers up to a 172-dB sound pressure level (SPL) and a temperature of 732°C (1350°F). The results for these transducers are summarized for different static pressures, operating SPLs, and temperatures.
Physics-of-Failure: An Approach to Reliable Product Development
Authors: Pecht Michael , Dasgupta Abhijit
Published: November 2020

Reliability assessments based on physics-of-failure methods incorporate reliability into the design process to prevent parts from failing in service. An understanding of the physics-of-failure is necessary in applications that afford little opportunity for testing, or for reliability growth. This paper presents an overview of physics-of-failure and a case study of the application of physics-of-failure to a specific failure mechanism called conductive filament formation.
Particle Formation of Materials Outgassed from Silicone Sealants by Corona-Discharge Ionizers
Authors: Namiki Norikazu , Otani Yoshio , Emi Hitoshi , Fujii Shuji
Published: November 2020

Particle formation of LMCS (low-molecular-weight poly-cyclo-dimethyl-siloxane) outgassed from silicone sealants by a corona-discharge ionizer was studied by measuring the number concentration and size distribution of formed particles as well as by qualitative analyses of formed particles with FT-IR (Fourier transformation infrared spectroscopy). Further, the influence of humidity and oxygen on the particle formation was investigated to find the reaction mechanisms. As a result, it was found that the LMCS is polymerized to form particles with two different reaction paths and that the LMCS is one of the major species that contribute to the formation of silicon-containing particles in cleanroom environments.
A Maturity Metric for Accelerated Testing of Complex subsystems and Assemblies
Authors: Ellner Paul , Woodworth John
Published: November 2020

Prior to system integration testing, assemblies and subsystems are frequently subjected to tests that seek to surface failure modes associated with a specified set of environmental conditions. The induced environmental stresses are often elevated above normal usage levels to shorten the test duration necessary to surface the failure modes. One natural question that arises is how long should the unit under test be subjected to the environmental conditions. Once we have surfaced a sufficient set of failure modes, our resources should be redirected toward eliminating the surfaced modes and toward testing additional assembly (or subsystem)/environment combinations of interest. In this paper, we propose a metric for use in deciding when sufficient testing has been accomplished for a complex assembly or subsystem in a specified environment. The proposed metric utilizes the first occurrence times of the observed problem failure modes. We propose a related metric for the discrete case where test duration is measured in terms of trials or duty cycles.
Rationale for Durability Temperature Test Compression
Authors: Caruso Hank
Published: November 2020

This paper describes temperature test compression strategy suitable for use with either commercial or military electronic products. An example, with calculations and supporting rationale, is presented for developing an accelerated temperature test profile for a representative electronics product based on actual conditions in its service environment. Both operating and nonoperating periods are considered over a full range of hot, cold, sunny, and cloudy days. Test compression is based on equivalent amounts of fatigue accumulation in the test laboratory and in actual service. Significant assumptions and variables that can affect estimates of fatigue accumulation and test validity are also discussed.
Laboratory Simulation of Low Earth Orbit (LEO) Atomic Oxygen Effects
Authors: Caledonia George , Krech Robert , Oakes David
Published: November 2020

Our pulsed fast oxygen atom source has been used extensively over the last 9 yr to investigate the effects of ambient oxygen atoms that impact materials placed in LEO. During this period, we have irradiated over 2000 material samples with 8 km/s oxygen atoms generated in our source. Typical irradiance level is 3 × 1020 O atoms/cm2 although some materials have been irradiated to fluence levels as high as 6 × 1021 O atoms/cm2. In this paper, we review the operating principles and characteristics of our source along with the diagnostic and handling procedures appropriate to material testing. We then present representative data on the velocity dependence of oxygen atom erosion rates (the PSI source provides oxygen atoms tunable over the velocity range of 5 to 12 km/s) as well as the dependence on material temperature. Specific examples of nonlinear oxidative effects related to surface contamination and test duration will also be provided.
Optimizing Environmental Stress Screening Using Mathematical Programming
Authors: Mok Y. , Xie M.
Published: November 2020

Environmental stress screening (ESS) is widely used in the electronics industry as a means of removing early failures. It is a process that calls for proper planning because inadequate duration is ineffective and prolonged screening can incur unnecessary costs. This paper describes an approach that uses mathematical programming to ensure that the right amount of screening is in place at each assembly level. Factors considered are screening cost and desired operational reliability.
Characteristics of an Ultrafiltered Deionized Water System Used in the Manufacture of Implantable Biomedical Devices
Authors: Hjelle Mark , Bauer Michael
Published: November 2020

The purpose of this paper is to demonstrate the characteristics of an ultrafiltered deionized water system used in the manufacture of biomedical devices. The water system was designed to reduce product concerns with respect to ionic contamination, organic contamination, and microbial contamination. The goal of the system was to produce high-purity deionized water that exceeded the requirements of USP pure water and meet the manufacturing requirements of electronic device assembly. This goal was achieved by using a compact design, select materials of construction, and robust pretreatment to reduce the burden to the ultrafiltration system. Continuous supply is delivered to all points of use through balanced pressures within the system and without a bulk storage tank. System maintenance is reduced to routine daily monitoring and sanitization once per month. Detailed descriptions of the system design, system operating conditions, and variable data are included to demonstrate system performance.
Development and Evaluation of On-Line Detection Techniques for Polar Organics in Ultrapure Water
Authors: Frye Gregory , Blair Dianna , Schneider Thomas , Mowry Curtis , Colburn Chris , Donovan Robert
Published: November 2020

An on-line monitor that can perform rapid trace detection of polar organics such as acetone and isopropanol in ultrapure water (UPW) is necessary to efficiently recycle water in semiconductor manufacturing facilities. The detection of these analytes is problematic due to their high solubility in water, resulting in low partitioning into sensor coatings for direct water analysis or into the vapor phase for detection by vapor phase analyzers. After considering various options, two conventional laboratory techniques have been evaluated: gas chromatography and ion mobility spectroscopy. In addition, optimizations of sensor coating materials and sample preconditioning systems were performed with the goal of a low-cost, chemical sensor system for this application. Results from these evaluations, including recommendations for meeting the needs of this application, are reported.
Transient Synthesis Using a Fourier Transform Envelope: An Alternative to Swept-Sine Vibration Testing
Authors: Hine M.
Published: November 2020

Transient vibration test offer an alternative to the conventional swept-sine vibration test, with controllable conservatism. A method of deriving a single vibration test transient from several spacecraft flight transients is described. These transients were from different physical locations on the spacecraft. The test transient was derived by taking the inverse Fourier transform of an envelope of the Fourier transforms of the flight transients. The inverse transformation was performed using the real and imaginary parts of that Fourier transform forming the envelope amplitude at each frequency. The test transient therefore has the same frequency content and maximum amplitudes as the flight transients. A generic test transient was therefore produced that duplicates many operating conditions at separate physical locations. It could be applied to many different structural components of a spacecraft, simplifying a vibration test program. The transient vibration test produces significantly less overtest than a conventional swept-sine vibration test.
Multi-Resolution Processing for Random Vibration Control
Authors: Karshenas A. , Dunnigan M. , Williams B. , Goodfollow J.
Published: November 2020

A typical vibration test for a specimen is to subject it to a specific spectrum of random vibration. This paper proposes multi-resolution processing using a "frequency domain self-tuning" algorithm for application to random vibration control. MATLAB programs simulate two-octave-band and three-octave-band processing for random vibration control. A PC-based, digital signal processing (DSP) board was used to implement two-octave processing. The simulation and practical results are presented.
Lessons Learned in Predicting Launch Vehicle Vibroacoustic Environments
Authors: Tanner Carole
Published: November 2020

Lessons learned in predicting the vibroacoustic environments for launch vehicles are reviewed. Elements cover prediction methods, ground test experiences, use of flight data in extrapolating environments, and flight data results for DoD launch vehicle systems.
A Method for Implementing Force-Limited Vibration Control
Authors: Worth Daniel
Published: November 2020

NASA/Goddard Space Flight Center (NASA/GSFC) has implemented force-limited vibration control on a controller which can only accept one profile. The method uses a personal computer-based digital signal processing board to convert force and/or moment signals into what appears to be an acceleration signal to the controller. This technique allows test centers with older controllers to use the latest force-limited control techniques for random vibration testing. The paper describes the method, hardware, and test procedures used. An example from a test performed at NASA/GSFC is used as a guide.
Instrument Design For Sub-PPB Oxygenated Contaminants Detection in Semiconductor Processing
Authors: Man Kin , Boumsellek Saïd
Published: November 2020

This paper describes a technique for measuring trace quantities of oxygen and moisture contaminants present in a semiconductor and/or containerless processing environment. Monatomic negative oxygen ions, O-, formed by electron dissociative attachment through interaction with the molecular oxygen and water, are measured to infer the presence of the contaminants. This technique exploits the fact that the cross section for the reaction is greatly enhanced at the resonant energy. The device built to demonstrate this technique combines a small gridded electron ionizer with a conventional mass spectrometer. The concentrations of oxygen have been measured using the method of standard additions by diluting O2 in N2. The lowest detection limit obtained was 1.2 kHz (O- count rate) at a concentration of 1010 corresponding to 0.1 ppb. Sensitivity calculations for detecting moisture, and electron and ion trajectory modeling using the SIMION program are presented. The detection of trace quantities of water vapor was attempted. The difficulties with handling water in the experiments are also described.
Characterizing Electrodynamic Shakers as a Two-Port Network
Authors: Smallwood David
Published: November 2020

An electrodynamic shaker is modeled as a mixed electrical/mechanical system with an experimentally derived two-port network characterization. The model characterizes the shaker in a manner that the performance of the shaker with a mounted load (test item and fixture) can be predicted. The characterization depends on the measurements of shaker input voltage and current, and on the acceleration of the shaker armature with several mounted loads. The force into the load is also required and can be measured directly or inferred from the load apparent mass.
On Generic Vibration Criteria for Advanced Technology Facilities: with a Tutorial on Vibration Data Representation
Authors: Amick Hal
Published: November 2020

The design of vibration-sensitive advanced technology facilities generally involves considerable attention to structural and mechanical aspects. In most cases, the vibration control measures contribute significantly to a facility's cost. The selection of a vibration criterion for use in design is an important step in the design process. Many process equipment manufacturers have provided tool-specific criteria, and the literature contains several forms of "generic" criteria. Unfortunately, there is no standardization in either tool-specific or generic criteria, and considerable confusion can arise, often due to the forms of data representation used. This paper first reviews some of the relevant fundamentals of signal processing, then uses experimental data to develop a tool-specific vibration criterion for an optical microscope. Two dissimilar approaches to generic criteria are discussed, and their signal-processing requirements are examined. They are compared with a manufacturer's published vibration criteria for a projection aligner. Recommendations are given for future development of tool-specific criteria.
Mars Pathfinder Spacecraft, Lander, and Rover Testing in Simulated Deep Space and Mars Surface Environments
Authors: Johnson Kenneth
Published: November 2020

The Mars Pathfinder (MPF) spacecraft was built and tested at the Jet Propulsion Laboratory during 1995 and 1996. MPF was launched December 4, 1996, and successfully landed on Mars on July 4, 1997. The testing program required that the mission hardware be subjected to both deep space and Mars surface conditions. A series of tests were devised and conducted from January, 1995, to July, 1996, to study the thermal response of the MPF spacecraft to the environmental conditions to which it was to be exposed during the cruise phase (on the way to Mars) and the lander phase (landed on Mars). In addition, several tests were conducted to study the thermal characteristics of the Mars rover. Sojourner, under Mars surface environmental conditions. Several special test fixtures and methods were devised to simulate the required environmental conditions. Creating simulated Mars surface conditions was a challenging undertaking since the Mars surface is subjected to diurnal cycling between -20°C and -85°C, with wind speeds to 20 m/sec, occurring in an 8 torr CO2 atmosphere. This paper describes the MPF test program conducted at JPL to verify the MPF thermal design.
A Strategy to Integrate the 'Tailoring' and 'Stimulation' Test Philosophies
Authors: Aldrige Dustin
Published: November 2020

This paper considers the benefits and liabilities of the tailoring and stimulation test philosophies. It introduces a hybrid strategy to link the tailoring and stimulation test philosophies into an integrated philosophy with implementation examples. A methodology to create generic environmental requirements through Weibull analysis of historical databases is presented. The implications in the hybrid philosophy are discussed along with reliability demonstration considerations. Examples of product requirements are provided for vibration and thermal environments.
Minimum Sampling Time/Volume for Liquid-Borne Particle Counters and Monitors
Authors: Xu Mindi , Wang Hwa-Chi
Published: November 2020

A particle counter is an instrument that measures particles in all the fluid passing through its sensor, and a particle monitor measures particles only in a portion of the fluid. For liquid with an ultralow particle concentration, particles may not disperse uniformly in the liquid. Therefore, the concentrations may vary significantly from measurement to measurement if the sample volume is not large enough. To achieve the same precision, a minimum sampling time or minimum sample volume for a particle instrument needs to be specified. A Poisson distribution was used to describe the distribution of particle counts. Testing included a series of particle concentration measurements. Minimum sampling time or sample volume at a given average concentration with different error levels was determined for selected commercial particle instruments. At the same flow rate, a particle monitor always requires a longer sampling time than a particle counter to achieve a specific precision for a given concentration. The minimum sampling time also varies among instruments because of the difference in sample volume in which the particles are counted. Experiments with a particle monitor have been conducted to thest the changes in average particle concentration and the standard deviation at different operating conditions.
The protective effect of AT1-antibody against myocardial ischemia-reperfusion injury through inhibition of inflammation and apoptosis
Authors: R. Hadi Najah , G. Al-Amran Fadhil
Published: November 2020

Myocardial ischemia and reperfusion (I/R) injury is known to occur on restoration of coronary flow after a period of myocardial ischemia. Angiotensin II (Ang II) is the most important bioactive substance of the renin-angioensin system (RAS), and exerts its physiological actions through AT1 receptors by regulating vascular tension and blood flow, and promoting cell growth and proliferation. The aim of the present study is to investigate the effects and its possible underlying mechanisms of AT1-AB on myocardial ischemia/reperfusion (I/R) injury. To test this hypothesis, we randomly assigned four groups (six mice per group) for experiment. To produce myocardial injury, the left anterior coronary artery (LAD) was occluded for 30 min, followed by 120 min of reperfusion in anesthetized mice. In the mice heart subjected to I/R injury, pretreatment AT1-AB (1mcg/gm) decreased the pathological scores of myocardium, and significantly attenuated I/R-induced increases of myocardial TNFα, IL-1β, IL-6. Further, 1mcg/gm AT1-AB significantly attenuated cTn-I and reduced apoptosis index of cardiac muscle cell of mice subjected to I/R injury. Therefore, these results demonstrate that AT1-AB exhibits significant protective effect against myocardial I/R injury which is related to inhibition of the release of inflammatory cytokines and the apoptosis of cardiac muscle cell.
The functionality of cell mediated immunity in the pathogenesis of Schistosoma japonicum
Authors: Chen Wen-jian , Xie Xuefeng
Published: November 2020

Schistosomiasis japonica is a serious disease caused by the parasitic worm Schistosoma japonicum. The induction of granulomas that form around the eggs in the liver around which are reported to be positively depends upon cell mediated immunity, and there is evidence that increased production of proinflammatory cytokine is associated with strong tissue destruction observed in Schistosomiasis japonica. We investigate the role of regulatory cytokines and cytokine antagonists in the downregulation of immune response in Schistosoma japonicum infection. Male wild type C57BL/6 mice were used, each mouse was infected with 10 cercariae of S. japonicum through the abdominal skin. Single cell suspensions of splenocytes and lymphocytes were prepared by mincing the mouse spleens and mesenteric lymph nodes. IL-10 and TGF-β downmodulate TNF-α and IL-17 production, Neutralization of TNF-α decreased IFN-γ level and the neutralization of IFN-γ decreased TNF-α level and increased IL-10 production. Our study is report that IL-10 and TGF-β are cytokines that appear to be more involved in modulation of immune response in Schistosomiasis japonica.
Role of macrophages in Guillain-Barré syndrome: contributes with the outcome
Authors: G. Andrews Robert , Lin, Limin Lee Yixin
Published: November 2020

Guillain-Barré syndrome (GBS) occurs throughout the world with a median annual incidence of 1.3 cases per population of 100 000, with men being more frequently affected than women. GBS is currently divided into the two major subtypes: acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN) and clinically is defined as an acute peripheral neuropathy causing limb weakness that progresses over a time period of days or, at the most, up to 4 weeks. Campylobacter jejuni, cytomegalovirus, Epstein-Barr virus and Mycoplasma pneumonia are commonly identified antecedent pathogens. Strong evidence now exists that axonal subtypes of Guillain-Barré syndrome is caused by antibodies to gangliosides on the axolemma that target macrophages to invade the axon at the node of Ranvier, further, macrophages infiltrate peripheral nerves and may contribute to neural damage in the GBS. This review highlights relevant recent publications, particularly on the outcome of macrophages in Guillain-Barré syndrome.
Distinct roles of Toll-like receptor-4 expression in neonate infected by neonatal meningitis
Authors: B. Smith Jack , Hijiya Enza
Published: November 2020

The objective of the study is to evaluate the expression of Toll-like receptor-4 (TLR-4) in neonate infected by neonatal meningitis. Thirty neonate under the age 30 days with the clinical suspicion of neonatal meningitis were enrolled in the study. CSF and Nasopharyngeal secretions were obtained for laboratory testing, and blood samples were obtained for flow cytometry and cytokine level analysis. The mean fluorescence index, used as a measure of TLR-4 expression by monocytes, was significantly higher with neonatal meningitis than in the control group neonate (51.26 ± 29.41 vs. 28.22 ± 12, respectively; P= 0.002). We concluded that TL4 expression by monocytes are higher in neonate with positive PCR results for neonatal meningitis.
Analysis of white coat hypertension in type 2 diabetic patients: 24-hours versus 48-hours monitoring
Authors: Rajooj Hmood Abdulhamza , Abbas Aldabbagh Laith
Published: November 2020

ABPM is the best method of detecting WCH in diabetic patients. We report ABPM findings in 100 diabetic individuals with WCH during 2 years. All of the referred subjects underwent casual and ambulatory blood pressure measurements. The mean age of participants was 41.43 year (±13.3 SD) and the age range from 19–74 years; majority were male (80%). The proportion of ambulatory-confirmed average 24-hours true hypertension was significantly reduced when the duration of the study was increased to 48 hours (P<0.001). Day-time systole (P=0.036) as well as night-time systole (P=0.001) and diastole (P<0.001) were statistically different during the two period of monitoring. Dipping pattern had increased from 53% to 60% (P=0.02) but non-dipper pattern was a common finding. Blood pressure load had been normalized in 19% of patients when the duration of study increases to 48 hours (P<0.001). WCH was common in T2DM and the best diagnostic tool was 48-hours ABPM. The dominant rhythm was dipper and absence of nocturnal drop was also common. Blood pressure load might be accurately determined with 48-hours ABPM.
Magnesium sulfate ameliorates cerebral ischemia reperfusion injury via interfering with inflammatory and oxidative pathways
Authors: R Hadi Najah , M Hasan Ahmed
Published: November 2020

Magnesium sulfate has neuroprotective effects and decrease overall neuronal firing. It is also decrease firing of excitable tissues outside the brain. We study the anti-inflammatory and antioxidant effects of magnesium sulfate in rat brain following ischemia reperfusion (I/R) stress. Twenty four rats were grouped into 4 groups: The first (sham group), the second (control) and the third group(control-vehicle) and the forth (treated with Magnesium sulfate). Animals in the second group underwent bilateral common carotid artery ligation without treatment, whereas the forth group were injected with magnesium sulfate 250mg/kg intraperitoneally before procedure. Brain homogenate were prepared after the procedure for measurement of cerebral level of IL-6, IL-9, MCP-1 and ICAM. Cerebral level of IL-9 in control group was 163.3 ± 30.4 pg/mg and it significantly decreased in magnesium sulfate treated group (21.8 ± 1.72 pg/mg). Cerebral level of MCP-1 in the control group was 109.05 ± 18.2 pg/mg, while it significantly reduced in magnesium sulfate treated group (38.16 ± 3.54 pg/mg). Mean cerebral levels of ICAM of control was 362.8 ± 26.81 pg/mg while mean cerebral level of ICAM in treated group was 35.5 ± 4.71 pg/mg. We concluded that magnesium sulfate significantly decreasedcerebral inflammatory markers IL-6, IL-9, MCP-1 and ICAM in global ischemia model in rats and regressed I/R injury
Proinflammatory cytokine and cancer
Authors: Zheng Song , Wang Wu
Published: November 2020

Many investigators have suggested that different cytokines may be important players in the development and progression of cancer and tumor biology. Cytokines are integral to many different aspects of cancer, including development/advancement, treatment, and prognosis. However, so far most cytokine -based therapy trials have fallen short of expectations. One of main obstacles is the difficulty to achieve therapeutically relevant dosage in patients without generating excessive normal tissue toxicity. Furthermore, cytokine profile levels have been used to predict cancer prognosis as differential cytokine expression profiles have been correlated with disease progression. Cytokines can also influence the effectiveness of cancer treatments. Elevated cytokine levels have been associated with reducing the anti-cancer activity of various treatments. In this review, we demonstrated the applicable action of cytokines in cancer pathogenesis and treatment.
HTRA1 enhance signaling pathway of uveitis via modulation of the TGF-β signaling cascade
Authors: Vierkotten Sascha , Korinek Victoria
Published: November 2020

High temperature requirement protein A1 (HtrA1) is a serine protease that is mostly secreted to degrade numerous extracellular matrix proteins, They are involved in the development and progression of several pathological processes such as cancer, neurodegenerative disorders and arthritic diseases, but it also exists within cells for some partially understood. The purpose of this study was to investigate the role of HTRA1 in the uveitis, and the possible mechanisms involved. Interphotoreceptor retinoid-binding protein peptide R14 to induced uveitis in rat model. A recombinant lentiviral vector carrying HTRA1-shRNA to knockdown HTRA1 expression. ELISA to detected proinflammatory cytokines and standard molecular biological techniques were used for subcloning of HtrA1. The knockdown of HTRA1 was associated with decreased the cellularlevel expression of proinflammatory cytokine resulted in reduced cellular damage, and increased mRNA levels of TGF-β1.
Protection effects of 17β-estradiol in lung injury following burn trauma via suppressed NF-κB-mediated inflammation pathways
Authors: J Arcaroli Juan , H Relja Daniel
Published: November 2020

Acute lung injury (ALI) is a leading complication in patients with extensive burns. The aim of this study was to assess the effects of 17β-estradiol in acute lung injury after burn. Male wild type C57BL/6 mice were subjected to 30% total body surface area steam burn with and without 17β-estradiol treatment. A control of animals were treated with 17β-estradiol without subjected to burn. The burned animals were sacrificed 24 h after burn injury. Lung tissue immunohistochemistry, ELIZA technique to assay plasma cytokines, tissue MCP-1, and KC levels. Lung tissue NF-kB was analyzed by immunoblot. Data showed that, 17β-estradiol significantly inhibited the NF-κB expressions in the lungs, and improved the pulmonary histologic changes induced by burn trauma, decreased the proinflammatory cytokine and chemokine in lung tissue and serum. Further, 17β-estradiol suppressed MPO activity, and reduced the MDA content in the lungs after severe burn. These results suggest that 17β-estradiol protects against ALI induced by severe burn through attenuation NF-kB- mediated inflammatory response.
Notch-3 promote angiogenesis and proliferation of bladder cancer cells through the PI3K/Akt pathway
Authors: V. Draucker Joan , Talarico Irene
Published: November 2020

Transitional cell carcinoma (TCC) of the bladder is the most common form of bladder cancer and is manifested in two distinct forms with different clinical and biological behaviors. Approximately 70% of patients present with non-muscle invasive tumors, while the remaining 30% present with muscle-invasive tumors. Despite good prognosis for patients with superficial disease, recurrence is common and is associated with development of muscle-invasive disease. Seventy seven tissue specimens from bladder cancer patient [32- noninvasive and 45- muscle invasive] and forty specimens from patients with benign prostatic hypertrophy as control were enrolled. The specimen’s tissue was halved into either in 10% neutral buffered formalin for histological process or snap frozen storage in liquid nitrogen. Tissue RNA and protein were examined by qPCR and western blot for Noch-3 and PI3K/Akt pathway respectively. One-Way ANOVA with Bonferroni tests was applied, with significance accepted at P<0.05. Our results highlight critical, overlooked functions for Notch-3 in regulating angiogenesis and proliferation of bladder cancer cells and suggest that Notch-3 inhibitor may be drug target in bladder cancer. Further investigation into the precise mechanism for this protection is warranted.
Análise Funcional: tecnologia para o controle de comportamentos alimentares problema
Authors: Bueno Gina Nolêto , Magri Maíra Ribeiro , Nogueira Guliver Rebouças
Published: November 2020

Resumo: este estudo apresenta três modelos de intervenções analítico-comportamentais sobre o comportamento alimentar problema (comportamento bulímico, comer compulsivo na obesidade e comportamento de anorexia nervosa). Essas pesquisas pautaram-se na tecnologia comportamental, cujo foco principal foi a análise funcional. Os resultados apontam conquistas relevantes à identificação e ao controle das variáveis causadoras e mantenedoras dessas classes de respostas.

Palavras-chave: Transtornos Alimentares. Análise Funcional. Análise do Comportamento Aplicada.
The Benefits and Costs Of Decarbonizing Costa Rica's Economy: Informing the Implementation of Costa Rica's National Decarbonization Plan under Uncertainty
Authors: Groves David G. , Syme James , Molina-Perez Edmundo , Calvo Carlos , Víctor-Gallardo Luis , Godinez-Zamora Guido , Quirós-Tortós Jairo , De León Felipe , Meza Murillo Andrea , Saavedra Gómez Valentina , Vogt-Schilb Adrien
Published: November 2020

Given the socioeconomic impacts of the COVID-19 pandemic, global leaders are seeking solutions to re-activate their economies while preserving the climate and mitigating the risk of future environmental crises. Costa Ricas National Decarbonization Plan sets the ambitious goal to become carbon neutral by 2050 and lays out a series of actions that government officials, sectoral stakeholders, and more generally Costa Rican citizens would need to implement throughout the economy to decarbonize. The extent to which the implementation of the decarbonization plan can be part of an effort to restart the economy post covid depends on the costs and socioeconomic benefits it entails. In this study, we developed an integrated model that estimates the benefits and costs of implementing the decarbonization plan in all major sectors, informed by consultations with numerous government agencies, industries and non-governmental organizations. In our central scenario, decarbonization brings $41 billion in net benefits to Costa Rica between 2020 and 2050, using a 5 percent discount rate. In the land use sector, reducing emissions would lead to increased agricultural and livestock productivity, and increasing carbon sequestration by forests would lead to greater ecosystem services, such as renewable forestry products, water and soil benefits, and support for tourism and cultural heritage. In the transportation sector, the economic benefits from energy savings, fewer accidents, time saved from reduced congestion, and the reduced negative impacts of air pollution on health more than compensate for the initially higher upfront costs of switching to electric vehicles and building infrastructure for zero-emissions public transport. Energy savings in buildings, efficiency gains in industry, and the economic value of recycled materials and treated water complete our estimates.
Isolation and characterization of 17 polymorphic microsatellite loci for a sea urchin (Echinometra lucunter: Echinometridae)
Authors: Benavides Serrato Milena , Contreras-Rueda Yully Fernanda , Barrios-Gardelis Lina M. , Fox Graeme , Hughes Thomas D. , Campos-Campos Néstor Hernando , Preziosi Richard
Published: November 2020

As a first step to establish the genetic structure of the sea urchin Echinometra lucunter lucunter throughout the Caribbean Sea, 26 microsatellite loci were isolated using Illumina paired-end sequencing, Next Generation Sequencing (NGS). We successfully optimized 17 loci for genotyping and the variation tested for 23 individuals from the Caribbean Sea and Tropical Eastern Atlantic Ocean. The allele number per locus (Na) ranged from four to 24, the observed heterozygosity (Ho) from 0.682 to 1, and the expected heterozygosity (He) from 0.609 to 0.9304. We detected no linkage disequilibrium between pairs of loci. These microsatellites will be used for the first time to detect the influence of marine barriers to genetic flow in the sea urchin E. lucunter lucunter throughout the Caribbean Sea. These new validated markers will be essential for current conservation and connectivity studies across the Caribbean Sea and the Atlantic Ocean.
Densidad poblacional de la guacharaca colombiana (Ortalis columbiana) en un fragmento de bosque subandino en el Valle del Cauca, Colombia
Authors: Roncancio-Duque Néstor Javier
Published: November 2020

Las especies endémicas con requerimientos ecológicos muy específicos o bajas densidades poblacionales son prioritarias en términos del diagnóstico de su estado de conservación. Para conocer el de una especie es necesario determinar su abundancia y su tendencia en el marco de programas rigurosos de monitoreo. El territorio del Valle del Cauca ha sido muy intervenido y actualmente solo existen remanentes de bosque, entre ellos, la Reserva Natural Bosque de Yotoco (RNBY), en el municipio de Yotoco. Allí habita Ortalis columbiana, especie endémica de Colombia, cuya densidad no ha sido documentada. En ese contexto, se estimó la densidad poblacional para conocer el estado de conservación de esta especie en la RNBY mediante el método de muestreo por distancia con 32 transectos lineales y más de 200 km de esfuerzo de muestreo. Se encontró una densidad poblacional de 19,2 ind/km2 (IC95%: 9,8-37,6) con un tamaño medio de grupo de 1,56 individuos (IC95%= 1,4-1,8). Este resultado es relativamente mayor que las estimaciones hechas para otras especies de crácidos, únicos referentes de comparación, y sugiere que la población sería de cerca de 100 individuos solo en la Reserva. Este tamaño poblacional podría considerarse bajo para mantener una población viable, no obstante, es importante considerar su presencia y abundancia en los agroecosistemas adyacentes para llegar a conclusiones sobre su viabilidad poblacional.
Sillimanita en esquistos y cuarcitas de los Esquistos del Silgará en el cerro La Ventana, macizo de Santander, Colombia: implicaciones petrológicas
Authors: García-Ramírez Carlos Alberto , Rey-Roman María Paula , Martínez-Vertel Jose Jaime
Published: November 2020

La presencia masiva (18 y 52 %) de sillimanita (Sil) en esquistos y cuarcitas de la unidad   Esquistos del Silgará en los sectores del cerro La Ventana y la cuchilla Frailejones es un caso único en el macizo de Santander en la cordillera Oriental de los Andes colombianos. En estas rocas se han reconocido dos tipos de sillimanita: Sil1, de la variedad fibrolita o prismática, y Sil2, de la variedad fibrolita (que se desarrolla en forma radial asociada con cuarzo). La asociación del pico metamórfico consiste en biotita+muscovita+cuarzo+plagioclasa+sillimanita1 con la formación de abundante sillimanita de la variedad fibrolita permitió determinar las siguientes condiciones: T=650-720 °C y P=5,5-6,9 Kb. Estas condiciones sugieren que las rocas sufrieron un gradiente metamórfico de cerca de 32 °C/ Km, típico de un metamorfismo barroviano. La  Sil2 se formó en una etapa ligeramente posterior al pico metamórfico en un ambiente menos deformado y posiblemente por el efecto termal debido al emplazamiento de ortoneises del Ordovícico Tardío. Las características geoquímicas evidencian que el protolito de estos esquistos y cuarcitas fueron pelitas asociadas con un margen continental activo.
Análisis genético de restos humanos precolombinos del Bajo Magdalena sugiere una ruta migratoria y continuidad genética matrilineal en el norte de Suramérica
Authors: Noguera-Santamaría María Claudia , Rivera-Sandoval Javier , Martín Juan Guillermo , Briceño-Balcázar Ignacio , Gómez-Gutiérrez Alberto
Published: November 2020

El análisis del ADN en restos de poblaciones prehispánicas ha permitido aproximarse al origen genético de una proporción importante de los habitantes de la actual Colombia. Los resultados arqueológicos de la tradición de Malambo, cuyo origen se remonta a 3.000 años A.P. en el bajo Magdalena, se complementaron con estudios genéticos de cuatro individuos asociados con esta población. Para ello se extrajo ADN de muestras de dientes y huesos. El ADN extraído se purificó y se amplificó por PCR para su posterior secuenciación y análisis filogenético. El haplogroupo B2j se identificó y se caracterizó mediante la mutación G16361A, así como la deleción de 9pb y las mutaciones diagnósticas del haplogrupo B. Este mismo haplogrupo fue descrito recientemente en un individuo en Venezuela, lo que sugiere la filiación genética matrilineal y su continuidad en el norte de Suramérica.
Problems and Countermeasures in the Process of Architecture and Design of Enterprises
Authors: Yang Lin
Published: November 2020

Researchers say that in recent years, driven by economic development, China’s construction engineering industry has developed vigorously. In this process, with the emergence of a large number of construction projects, the attention of all sectors of society to the quality of construction projects has been continuously improved. To solve this problem, as the main designer and builder of the project, the construction enterprises should actively analyze and explore the construction and design work according to the actual situation of the project, so as to effectively improve the comprehensive ability of their own engineering buildings and lay a foundation for further improvement and optimization of the engineering quality. In this study, the researchers explored and thought about the main problems existing in the design and construction of architectural engineering in China. In the process, the researchers put forward corresponding optimization countermeasures for related problems with their own professional knowledge, aiming at further improving and optimizing the comprehensive quality of architectural engineering.