Instability Research Articles

Overturning File Cabinet

It is deceiving that an otherwise super-stable file cabinet can become critically unstable when it is unloaded or lightly loaded. This may expose office workers to the specter of a 200 lb. file cabinet striking the floor at 13 mph. File cabinet design is guided by standards that do not reflect “worst case scenarios,” do not specify realistic safety loads, do not include snagging forces, and do not account for the effects of carpeting that may lower the tip resistance by 40%. This paper introduces three well known anti-tip concepts that radically improve the stability of file cabinets; elastic footprint extender, passively deployed outriggers, and rollers that trade off rotation for translation. These traditional concepts are added to the current arsenal of safety tip-over devices that include wall and floor bolting, ganging, under-mounting, counter-weighting, and single drawer deployment interlocks. The stability principles discussed are also applicable to such things as furniture, appliances, and tool cabinets.

Correlation between carotid atherosclerotic plaque properties and serum levels of lncRNA CCAT2 and miRNA-216b.

The purpose of this study was to uncover the clinical values of serum long non-coding RNA (lncRNA) CCAT2 and miRNA-216b in the properties of carotid atherosclerotic plaques. Patients with carotid atherosclerotic plaques were assigned into stable plaque group (n=60) and unstable plaque (n=75) group based on their examination results of cervical contrast-enhanced CT examination. Maximal plaque thickness (MAPT) and intima-media thickness (IMT) in each group were determined. Serum levels of lncRNA CCAT2 and miRNA-216b in patients with carotid atherosclerotic plaques were detected by Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR). Moreover, the correlation between serum levels of CCAT2 and miRNA-216b was analyzed by Pearson's correlation analysis. Besides, potential correlations of serum levels of CCAT2 and miRNA-216b with MAPT and IMT in patients with carotid atherosclerotic plaques were assessed as well. Results revealed that MAPT and IMT were markedly higher in unstable plaque group than those in stable plaque group. Serum level of CCAT2 was higher in unstable plaque group, while miRNA-216b was lower than those in stable group. A negative correlation was identified between serum levels of CCAT2 and miRNA-216b. In addition, CCAT2 level was positively correlated with IMT and MAPT in patients with carotid atherosclerotic plaques, while miRNA-216b level was negatively correlated with them. Detection of serum levels of CCAT2 and miRNA-216b could be applied for predicting the rupture of carotid atherosclerotic plaques. They may be potential biomarkers predicting ischemic stroke.

Changes in the Rotation Axis of Earth After Asteroid/Cometary Impacts and their Geological Effects

In this paper sudden shifts of the poles are proposed as an explanation for the recurrent geological crisis during which volcanic eruptions, orogenesis, climatic changes, sea levels variations, together with mass extinctions occur. Such shifts are usually considered impossible on the assumption that only a planetary impact could change in a significant way the Earth’s momentum. The position of the poles, however, is determined by the equatorial bulges; if they are “reshaped” for some reason, the poles shift without any significant change of the momentum. Due to the enormous extend of its oceans, Earth is an inherently unstable planet, so much so that a kick apparently irrelevant can trigger a process that in a very short period, that is instantaneously in geological time, provokes a reshaping of the equatorial bulge, thus making the poles shift permanently. When this happens all the masses on its surface, atmosphere, oceans and continents, are suddenly subjected to tangential forces, thus triggering a global catastrophe and long lasting effects for what concerns climate, volcanism and circulation cells of the mantle.

Non-uniform wind environment in mountainous terrain and aerostatic stability of a bridge

The existence of a dam has potential effects on the surrounding wind environment especially when it is located in mountainous areas. In this situation, the long-span bridge over the reservoir can easily be exposed to non-uniform incoming flows, affecting its wind-resistance performance. This paper presents a study on the aerostatic stability of such a bridge. Wind tunnel tests were first carried out to investigate the wind environment above a mountainous reservoir. The results show that the angle of attack and the wind speed along the bridge axis show obvious non-uniform characteristics, which is related to the inflow direction. When winds come from the south where the river is winding, the angle of attack varies along the span direction significantly. The finite element model for the bridge was established using ANSYS software, and effects of non-uniform wind loads on the aerostatic stability were computed. Non-uniform angle of attack and wind speed are unfavorable to the aerostatic stability of the bridge, especially the former. When the combined action of non-uniform angle of attack and wind speed is considered, the critical wind speed of aerostatic instability is further reduced. Moreover, the aerostatic stability of the bridge is closely related to the dam height.

Effect of crystals’ surface shape distortion on conversion efficiency of third harmonic generation

In the field of inertial confinement fusion (ICF), UV laser can effectively improve the beam-target coupling efficiency and suppress the hydrodynamic instability of laser plasma interaction. Using large aperture KDP crystal or KD*P crystal to triple the frequency of laser created by high power solid-state laser facility (wavelength is 1 μm) is an effective way to obtain high power UV laser output. At present, most high power laser facilities take method of I/II type third harmonic generation. The phase matching condition is required in the third harmonic generation, and the conversion efficiency is easily influenced by the detuned angle of crystals. The quality of the return light spot of crystals’ surface can reflect the state of wavefront distortion, and then evaluate the degree of angle-detuning at the crystal. The factors which create detuned angle are analyzed and judged, within which the surface shape distortion of crystals (PV is more than 30 μm) caused by clamping and gravity is the main part. According to improving the surface shape of crystals (PV is less than 10 μm) in the experiment, the quality of the return light spot of crystals has been significantly improved, and then the conversion efficiency of third harmonic generation has an obvious increase.

Disrupted Structural Connectivity in Prefrontal Areas in Borderline Personality Disorder

Many of the core features of borderline personality disorder (BPD; irritability, impulsivity, emotional instability) suggest disruption in frontolimbic

Rapid Screening of Blood Mitochondrial D310 and D315 Mutations in Breast Cancer Patients

Aims: 'Poly C' stretch extending from 303 to 315 nucleotide positions known as (D310) by GeneBank within the non-coding region HVR-II of mitochondrial DNA (mtDNA) has been identified as a mutational hotspot of primary cancer. We aimed to find this mutation in Bangladeshi breast cancer patients and control samples for screening the changes in poly C stretches. Materials and Methods: We have analyzed a total of 98 breast cancer blood samples and 98 healthy control blood samples and extracted DNA from blood samples for direct sequencing using ABI®3130 Genetic Analyzer. Results: We observed 70.41% C insertion at 310 regions (P<0.001, OR = 16.30 and 95% CI=7.83-33.93) in breast cancer patient whereas it is present only in 12.24% healthy individuals. No alterations were observed in 29.59% breast cancer samples. We also check the mutation pattern at D315 regions, but no significant observation was found (P=1.00). Conclusions: This is the first study from Bangladeshi breast cancer (BC) patients indicating a relatively high frequency of D310 mutations, which suggests that mtDNA instability at D310 may be a common characteristic of BC, study also supports the hypothesis that mtDNA D310 screening may represent additional blood based biomarker for breast cancer prognosis.

Numerical Treatment of First Order Volterra Integro-Differential Equation Using Non-Polynomial Spline Functions

The approach given in this paper leads to numerical methods to find the approximate solution of volterra integro –diff. equ.1st kind. First, we reduce it from integro VIDEs to integral VIEs of the 2nd kind by using the reducing theory, then we use two types of Non-polynomial spline function (linear, and quadratic). Finally, programs for each method are written in MATLAB language and a comparison between these two types of Non-polynomial spline function is made depending on the least square errors and running time. Some test examples and the exact solution are also given.

The Impact Of Financial Liberalization On Economic Risk In The Asia Pacific Countries

In this study, we analyze the non-linear effect of financial liberalization policy toward the economic risk of the Asia Pacific countries with trade openness as a threshold variable. To do that, we apply the panel regression threshold proposed by Hansen (1999) as our method of analysis. Based on yearly data from 1975 – 2015, we find that there is a non-linear effect of financial liberalization on economic risk depending on the certain level of trade openness. Regarding this finding, we find that when the trade openness is below the threshold value, financial liberalization policy can reduce the economic risk of Asia Pacific countries. However, when the trade openness exceeds the threshold value, financial liberalization will increase the economic risk. So that, we conclude that an open domestic financial market that is followed by high degree of trade openness will tend to create an economic instability. Keywords: Financial Liberalization, Trade Openness, Economic Risk, Volatility

COVID-19 / Coronavirus Outbreak: Hemodynamic monitoring with PiCCO artery

During pandemics, medical staff become a key resource in treating and managing patients with these infectious diseases. To achieve the best medical care, relevant techniques and procedures must be taught to medical staff which minimize the risk of work-related transmission of infection. When carrying out hemodynamic monitoring in cardiovascularly unstable patients, it is possible to utilize a Pulse Contour Cardiac Output (PiCCO) catheter. This system utilizes a thermodilution method to analyze a patient’s cardiovascular status. This video highlights the placement and setup of a PiCCO catheter and system, including both the practical component and analysis of the thermodilution method, whilst taking into account important personal protection measures.

Effect of countermeasures on the galloping instability of a long-span suspension footbridge

The aeroelastic stability of a long-span suspension footbridge with a bluff deck (prototype section) was examined through static and dynamic wind tunnel tests using a 1:10 scale sectional model of the main girder, and the corresponding aerodynamic countermeasures were proposed in order to improve the stability. First, dynamic tests of the prototype sectional model in vertical and torsional motions were carried out at three attack angles (α= 3°, 0°, -3°). The results show that the galloping instability of the sectional model occurs at α = 3° and 0°, an observation that has never been made before. Then, the various aerodynamic countermeasures were examined through the dynamic model tests. It was found that the openings set on the vertical web of the prototype section (web-opening section) mitigate the galloping completely for all three attack angles. Finally, static tests of both the prototype and web-opening sectional models were performed to obtain the aerodynamic coefficients, which were further used to investigate the galloping mechanism by applying the Den Hartog criterion. The total damping of the prototype and web-opening models were obtained with consideration of the structural and aerodynamic damping. The total damping of the prototype model was negative for α = 0° to 7°, with the minimum value being -1.07%, suggesting the occurrence of galloping, while that of the web-opening model was positive for all investigated attack angles of α = -12° to 12°.

Inflation Targets Regime and global financial cycle: An assessment for the Brazilian economy

In light of the global financial cycle (GFC), this paper investigates the effectiveness of monetary policy in Brazil since the adoption of the inflation targeting regime. The theoretical section analyses monetary policy from the New Macroeconomic Consensus perspective, emphasizing the implications of the GFC. It also contrasts central bank theory with the post-Keynesian critique. For the empirical investigation, a Markov-switching vector autoregressive model is estimated from January 2000 to December 2017, combining the common variables from the empirical literature with the proxy for the GFC. The main results suggest that greater financial instability has a direct effect on domestic inflation . JEL codes : C14, E12, E42

Percutaneous endoscopic lumbar discectomy combined with oblique lateral interbody fusion for degenerative lumbar diseases with ruptured disc herniation

Objective To investigate the preliminary clinical and radiographic outcomes of percutaneous endoscopic lumbar discectomy (PELD) combined with oblique lateral interbody fusion (OLIF) for the degenerative lumbar spondylolisthesis, lumbar spine instability or lumbar spinal stenosis with ruptured disc herniation. Methods Data of 11 patients with degenerative lumbar spondylolisthesis, lumbar spine instability or lumbar spinal stenosis with ruptured disc herniation who had undergone PELD combined with OLIF between March 2017 to July 2018 in our spine surgery center were retrospectively analyzed. There were 5 males and 6 females with an average age of 61.2±6.8 years old. All the patients were diagnosed with degenerative lumbar diseases including lumbar spondylolisthesis (7 cases), lumbar spinal stenosis (3 cases) and segmental instability (1 case). The patients were treated with PELD combined with OLIF. The visual analogue scale (VAS) scores of low back pain and lower limb pain and the Oswestry disability index (ODI) of lumbar function, spinal canal anteroposterior diameter, intervertebral disc height, vertical diameter of intervertebral foramen, segmental angle and the whole lumbar lordotic angle were collected. Results All patients received PELD with local anesthesia before OLIF with general anesthesia. The mean operation time was 52.3±13.2 min and the mean blood loss was 10.9±4.7 ml for PELD. The mean operation time was 56.8±18.0 min and the mean blood loss was 65.5±24.6 ml for OLIF. All patients were followed up for an average of 11.2 months. At the latest follow-up, the mean VAS score for back pain was 1.3±0.8, the mean VAS score for leg pain 1.1±0.5, the mean ODI 14.6%±5.3%, thus all of those were improved significantly compared to those of pre-operation (t=10.37, 16.49, 8.73; P< 0.05). The radiographic results showed the mean pre-operative intervertebral disc height, vertical diameter of intervertebral foramen, spinal canal anteroposterior diameter, segmental angle, and lumbar lordosis angle was 7.1±1.2 mm, 15.3±2.2 mm, 6.2±1.3 mm, 10.2°±3.5°, 16.2°±6.2°, and thus all of those were increased significantly to the latest follow-up 11.5±1.8 mm, 19.2±2.6 mm, 10.4±2.5 mm, 19.3°±7.8°, 27.4°±8.3°, respectively (t=5.83, 4.21, 6.59, 10.32, 7.65; P< 0.05). One of the patients had weakness of flexor hip strength and one had a transient paresthesia immediately post-operation. All symptoms were relieved within 1 month. Another one case had cage subsidence and encountered serious back pain after 1 month, and alleviated after percutaneous pedicle screw fixation. Conclusion PELD combined with OLIF can overcome the limitations of OLIF with indirect decompression effects, resulting in successful direct neural decompression without posterior decompressive procedures and providing a satisfactory outcome for the patients with degenerative lumbar diseases with ruptured disc herniation. Key words: Lumbar vertebrae; Intervertebral disc degeneration; Endoscopy; Spinal fusion; Surgical procedures, minimally invasive

Application of self-anchored lateral lumbar interbody fusion in lumbar degenerative diseases

Objective To evaluate the efficacy of self-anchored lateral lumbar interbody fusion (SA-LLIF) for lumbar degenerative diseases. Methods During January to December in 2019, a total of 41 patients with lumbar degenerative disease were treated with SA-LLIF, included 18 males and 23 females, aged 59.6±11.3 (range 49-77) years. There were lumbar stenosis and instability in 17 cases, disc degenerative disease in 8 cases, degenerative spondylolisthesis in 8 cases, degenerative scoliosis in 5 cases, postoperative revision in 3 cases. And osteoporosis was diagnosed in 5 of them. The index level included L2, 3 in 2 cases, L3, 4 in 11 cases, L4, 5 in 20 cases, L2-L4 in 3 cases and L3-L5 in 5 cases. After general anesthesia, the patient was placed in decubitus position. The anterior edge of psoas major muscle was exposed through 6 cm incision and extraperitoneal approach. Further, the psoas major muscle was properly retracted to expose the disc. After discectomy, the intervertebral space was prepared and moderately distracted. A suitable fusion cage filled with auto iliac graft was implanted. Two anchoring plates were inserted into the cage. Then, the caudal and cephalic vertebral body and the fusion cage were locked. Results The operation was performed successfully in all the patients. The operation duration was 79.0±19.5 (range 60-100) min. Intraoperative bleed loss was 38.0±28.2 (range 15-70) ml. The patients were followed up for averagely 10.6±4.6 (range 4-15) months. The visual analogue scale decreased from preoperative 6.2±2.1 to 1.6±1.1 and Oswestry disability index decreased from 47.8%±15.1% to 11.0%±7.3%. X-ray showed that the spine alignment recovered satisfactorily. No cage displacement was found. Sinking (2-3 mm) of cage was found in 7 patients without obvious symptom despite transient lumbar pain in an obesity woman. The lumbar lordosis recovered from 36.4°±10.2° to 48.0°±10.7°, and intervertebral height recovered from 8.3±2.5 mm to 11.3±3.3 mm. The rate of spondylolisthesis recovered from 19.7%±4.4% to 9.3%±5.3%. Conclusion SA-LLIF can provide immediate stability and good results for lumbar degenerative diseases with stand-alone anchoring cage without posterior internal fixation. Key words: Lumbar vertebrae; Intervertebral disc degeneration; Spinal fusion; Surgical procedures, minimally invasive

Rotating Instability Characteristics in Compressor with Different Tip Clearances

Rotating Instability Characteristics in Compressor with Different Tip Clearances

ERODIBILIDADE DE SOLOS DERIVADOS DE ROCHAS DA SUÍTE SERRA DOS ÓRGÃOS: IMPLICAÇÕES PARA A INSTABILIDADE DE TALUDES DE CORTE

Problemas de instabilidade de taludes podem ser deflagrados por processos erosivos nos horizontes de solos saprolítcos. Nesses casos, a identificação das causas e a análise dos processos instabilizadores pode não ser uma tarefa trivial. Embora a associação dos processos de deslizamento e erosão seja relativamente comum, nem sempre as relações entre causa e efeito são bem definidas, podendo impactar significativamente os custos dos projetos e obras de instablização. Portanto, ainda é necessário avançar na identificação prévia das erodibilidades dos solos saprolíticos, os quais em condições críticas podem deflagrar a instabilidade dos horizontes superiores do solo. O principal objetivo desse manuscrito é avaliar índices que auxiliem na previsão da erodibilidade de solos saprolíticos e seu potencial na deflagração de processos de movimentos de massa em encostas ou taludes instáveis. Foram selecionados para análises dois perfis de solo, incluindo o solo saprolítico e os horizontes pedológicos, derivados de rochas da Suíte Serra dos órgãos e com registro de instabilidades e evidencias de feições erosivas observadas em campo, no município de São João de Meriti (RJ). Após a amostragem, os horizontes pedológicos e saprolíticos de cada perfil foram analisados quanto à mineralogia, propriedades físicas e mecânicas. Os resultados obtidos em laboratório confirmam as observações de campo quanto à elevada erodibilidade do solo saprolítico e seu potencial para deflagração de rupturas dos taludes de corte na região. Esse conhecimento fundamental é útil para assistir às autoridades municipais quanto ao uso do solo urbano, em especial, para a necessidade de se evitar cortes profundos e assim manter a preservação dos horizontes saprolíticos e o equilíbrio das encostas.

Ticagrelor-Induced complete heart block: A rare entity

Ticagrelor, a purinergic P2Y12 receptor blocker, is a potent platelet antagonist and an important component in the treatment for acute coronary syndromes identified to have a potential risk to cause bradyarrhythmias. Here, we report the case of a diabetic patient of unstable angina with left bundle branch block who was prescribed ticagrelor post angioplasty. Electrocardiogram (ECG) revealed a complete heart block after about 1 week. Ticagrelor was stopped and replaced by clopidogrel. The patient became asymptomatic and ECG showed baseline rhythm after 1 week of stoppage of ticagrelor.

The comparison of clinical outcomes of popliteal tendon recess and reconstruction technique

Objective To compare the objective and subjective clinical outcomes of recess procedure versus popliteal tendon reconstruction in patients with posterolateral corner injury. Methods From January 2012 to January 2017, patients who were eligible for inclusion in this study if they 1) had acute posterolateral rotational instability (PLRI) and were treated surgically in our institution, 2) were followed for a minimum of 2 years with examination under anesthesia results. The mean age was 34.5±7.4 years (range 20-45 years). According to Fanelli's classification, there were 31 type A, 17 type B and 6 type C cases. There were 26 patients in reconstruction group and 28 patients in recess group. Outcomes included subjective scoring systems (Lysholm score, Tegner score and International Knee Documentation Committee (IKDC) subjective score), knee stability examinations (the side-to-side difference (SSD) of tibial external rotation angle by dial test, posterior and varus stress radiograph) and second-look arthroscopic lateral gutter drive-through test during hardware removal operation. Results The mean follow-up duration was 30.2±4.9 months in reconstruction group and 32.2±9.9 months in recess group. At the final follow-up, there were no significant differences in Lysholm scores (reconstruction group: 70.1±15.5, recess group: 70.0±10.2; t=0.089, P=0.926), Tegner scores (reconstruction group: 3(2, 5), recess group: 2(1, 4); U=395.522, P=0.156), or IKDC subjective scores (reconstruction group: 74.8±19.3, recess group: 71.2±17.6; t=0.381, P=0.722) between the groups. No significant difference in SSD on posterior stress radiography (reconstruction group: 4.1±3.4 mm, recess group: 4.7±2.6 mm; t=0.918, P=0.345) or medial stress radiography (reconstruction group: 4.0±1.7 mm, recess group: 3.8±1.9 mm; t=0.208, P=0.820) was observed. There was no significant difference on SSD of dial test (reconstruction group: 1.5°±4.2°, recess group: 1.1°±4.0°, t=0.586, P=0.565). No positive lateral gutter drive-through test was observed in all groups. Conclusion Both recess procedure and popliteal tendon reconstructions significantly improve the knee stability and subjective outcomes of patients with PLRI. In a comparison with popliteal tendon reconstruction, the recess procedure has similar subjective and objective clinical outcomes. Key words: Collateral ligaments; Tendon injuries; Arthroscopy; Reconstructive surgical procedures

Cloning, prokaryotic expression, and enzyme activity of a UDP-glucose flavonoid 3-o-glycosyltransferase from mulberry (Morus alba L.) leaves

Background: Mulberry leaves are traditional Chinese medicines, which have pharmacological activities such as anti-inflammation, anti-oxidation, antitumor, and hypoglycemic. Moreover, flavonol glycosides are one of the main functional ingredients. However, the biosynthetic pathway involved in mulberry flavonol glycosides has not been clear. UDP-glucose flavonoid 3-O -glycosyltransferase (UFGT) is a key enzyme in the biosynthesis pathway of flavonol glycosides, which can glycosylate unstable flavonols to form stable flavonol glycosides. Objectives: In this article, MaUFGT , a cDNA encoding the UFGT from mulberry leaves, was cloned, codon optimized, and expressed in Escherichia coli to study its effect in vitro . Materials and Methods: Mulberry UDP-Glucose flavonoid-3-O-glucanotransferase (MaUFGT) gene was reverse transcription-polymerase chain reaction amplified using the cDNA obtained from young leaves of mulberry, and the full-length MaUFGT gene was synthesized by codon-optimized whole-gene synthetic method. Then, the plasmid pCzn1/MaUFGT was constructed and heterologously expressed in E. coli . After denatured, renatured, and purified, the recombinant protein was used to evaluate its function in vitro by determining the final product by high-performance liquid chromatography. Results: The target protein was in the range of 45–66 KD and mainly present in the form of inclusion bodies. The obtained protein was found to transfer UDP-glucose glycosyl moieties to the 3-hydroxyl group of quercetin or kaempferol to form the corresponding products in vitro . Conclusion: The MaUFGT was preliminarily proved to be involved in flavonoid 3-O -glucoside biosynthesis.

『비정규직법』과 근로자의 고용불안 : 기간제 근로자를 중심으로

본 연구는 2004년 8월에서 2019년 8월까지의 경제활동인구조사 근로형태별 부가조사를 이용하여 기간제 사용기간을 2년으로 제한하는 2007년의 비정규직 관련법이 비정규직, 특히 기간제 근로자의 고용불안에 미치는 영향을 분석하고 있다. 평균 근속기간, 1년 이하 근로자 비중, 2년 이상 근로자 비중 등의 기초 분석과 더불어 이중차분법의 계량모형을 이용하여 비정규직의 고용불안 추이를 분석한 결과, 비정규직 관련법의 제정 이후 기간제를 중심으로 비정규직의 고용불안이 악화되었다. 이러한 현상의 원인으로 일각에서는 글로벌 금융위기를 지적하고 있으나, 글로벌 금융위기는 비정규직 고용불안의 일시적 악화에만 영향을 주었을 뿐이다. 실증분석의 결과 비정규직 관련법의 제정으로 인해 기간제를 중심으로 한 비정규직 근로자의 고용불안이 심화된 것으로 판단된다.