bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction of Injection Rate and Production History for Multifluid Five-Spot Floods
Authors: Prats M. , Matthews C.S. , Jewett R.L. , Baker J.D.
Published: February 2020

Published in Petroleum Transactions, AIME, Vol. 216, 1959, pages 98–105.Paper presented at 33rd Annual Fall Meeting of Society of Petroleum Engineers in Houston, Tex., Oct. 5–8, 1958.

By mathematical analysis it was found that injectivity history of a uniform five-spot pattern can be calculated by rather simple formulas. These calculated injectivities were found to agree rather well with injectivities measured in a potentiometric analog. With this as a basis, a simple method was finally developed which allows prediction not only of rate of injection but also of rate and kind of production at the production well, for a uniform five-spot. Using this method formulas for the effective injectivity and production behavior of a waterflooded reservoir having a wide range in permeability can be calculated by considering that the reservoir consists of several layers, each having a uniform but different permeability. Rather good agreement is shown by a comparison of the observed production history of a field in the Illinois basin and that calculated by the methods just described.

INTRODUCTION

The importance of being able to predict the injection rates for a water flood is well known, for upon injection rate depends the life of the flood, the size of pumping and treating facilities, and the rate of oil recovery. One method of determining rates of injection is through a pilot flood.
Water-In-Oil Emulsion Cements
Authors: Patchen F.D. , Burdyn R.F. , Dunlap I.R.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 216, 1959, pages 252–257.

The composition and properties of a new type of cementing mixture are discussed. In these compositions, API Class A or C cements are added to a stable water-in-oil emulsion instead of the usual water. The cement disperses in the oil phase and remains out of contact with the water under normal conditions of mixing and storage. At higher temperatures, such as those encountered down-hole during placement, the emulsion breaks and cement hydration can then proceed.

An extremely low filtration rate is obtained; the major part of the filtrate is oil. Thickening times of the mixture may be increased to meet the 18,000-ft casing cementing schedule by varying the amount of emulsifier. As in conventional Portland cement mixtures, high-temperature strength retrogression can be overcome by addition of silica flour.

Results of several field applications show that mixing presents no difficulty if emulsion blenders are used and the emulsion is prepared beforehand.

Introduction

Water-in-oil emulsions, in which oil is the continuous or external phase and in which water exists as discrete droplets, have for some time been used successfully in drilling muds to reduce filtration loss. Applied to cement slurries, the same results are obtained; i.e., the fluid-loss is greatly reduced. In addition, thickening times may be extended, lower densities and strengths obtained, and water-base borehole fluids more easily displaced without contamination of the cement.

A low filtration rate is often a desirable property in oil well cements since loss of fluid increases placement difficulties and may also cause damage to water-sensitive producing formations. In the casing cementing operation where the cement slurry is pumped into the narrow annulus between open hole and casing, rapid loss of fluid to a porous formation can cause the slurry to thicken and plug the annulus before the desired fill is obtained. Where a casing or a liner is cemented against a productive formation and the well completed through perforations, the fluid lost between the time the cement first contacts the formation and the time a set is obtained may invade the zone past the depth of the perforations. If the sand contains a material which will swell upon contact with cement filtrate, permanent damage may result.
A New Experimental Model for Studying Transient Phenomena
Authors: Landrum Bobby L. , Flanagan Donald A. , Norwood Billy C. , Crawford Paul B.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 216, 1959, pages 33–37.

Herein is described a heat conduction model which has been developed to predict the pressure distribution within a reservoir being subjected to unsteady-state depletion. Although potentiometric models have been widely used to study reservoir pressure distribution, their application is limited to the study of steady-state cases. Electrical analyzers may be used to study unsteady-state phenomena, but their application and simulation have certain limitations.

Much of the now accepted theory of unsteady-state fluid flow in porous media has evolved from previous heat conduction knowledge. An analogy between the flow of fluid in an unsymmetrical reservoir and conduction of heat in a similarly shaped unsymmetrical metal plate is made to show adaptability of the heat conduction principle to transient reservoir cases.

A description of the model and necessary instrumentation is included. Data show influence of well location on pressure distribution during unsteady-state depletion. Application of results is made to a hypothetical reservoir and to a reservoir located in an irregular aquifer.

Introduction

Development of methods for predicting behavior of petroleum reservoirs has resulted partially from adaptation of electrical and thermal flow concepts to the flow of fluids through porous media.

Extensive investigation of electrical and thermal flow problems has resulted in mathematical solutions applicable to many reservoir problems. The relative ease of measuring electrical flow has brought wide acceptance of the use of the potentiometric model to study certain field problems.

Potentiometric models are restricted to the study of steady-state conditions because of the instantaneous response of electrical flow to changes in the applied potential. The electrical reservoir analyzer has been one of our most useful instruments for studying certain phases of unsteady-state behavior. Other than approximation techniques, no method exists for determining pressure distribution in an irregular reservoir during primary depletion.
Increased Drill Bit Life Through Use of Extreme Pressure Lubricant Drilling Fluids
Authors: Rosenberg M. , Tailleur R.J.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 216, 1959, pages 195–202.

Oil well drilling muds prepared with lubricating aids such as oil, graphite or mica will not produce a sufficiently strong protective lubricant film for the bit bearing surfaces under high load conditions encountered in drilling operations. Consequently, the damage to the bearing surfaces resulting from the absence of such a film frequently results in a shortening of the drill bit life.

Several different types of extreme pressure lubricating additives for use in muds have been developed. These additives are capable of providing a protective lubricating film for bearing surfaces subjected to high load pressures. A modified version of the Timken lubricant tester, an instrument commonly used for testing the extreme pressure lubricating properties of oils, is used for measuring and controlling the lubricating qualities of the mud.

Comparison tests made in the laboratory with 5 ⅝-in. tricone bits drilling on steel plates immersed in extreme pressure lubricating muds and conventional muds showed that the bearing life of those bits tested in the lubricating mud was three to four times greater than obtained with conventional muds. Drilling tests made with extreme pressure lubricating muds in West Texas increased over-all bit life three to fourfold, reduced drilling torque and wear on drill pipe and drill collars.

Introduction

Roller bit cones contain roller, ball and journal-type bearings that are subjected to very heavy loading during drilling operations in which the only lubricant available for these bearings is either water or drilling mud. These bearings must be able to operate satisfactorily in order for the cutting structures on the surface of the cones to be fully utilized. Frequently, the bearings wear to the point that the cones freeze and the bit must be pulled before the cutting structures on the cores become worn. In some instances the hearings continue to turn with severe wear but the cones, which are held on the bit by the bearings, drop off; and this causes an expensive fishing job. In other instances the bearings wear to the point that the cones pinch in causing an undergauge hole and delays to ream the hole. The advantage of increasing bit bearing life is self-evident.
Effect of Pressure and Temperature on Cavities in Salt
Authors: Brown K.E. , Jessen F.W.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 216, 1959, pages 341–345.

It is deemed feasible to store atomic reactor fuel wastes in salt dome cavities when the differential pressure acting on the cavity does not exceed 3,000 psi and the temperature is less than 400F. Tests at pressure increments of 1,000 psi were conducted on a 2-in, cylindrical cavity contained in a 6-in. long X 6-in. diameter salt core. The cavity exhibited stability under pressures up to 3,000 psi and temperatures to 300F. At temperature ranges of 100 to 400F and with pressures of 5,000 psi and above continuous deformation of the cavity resulted. Initial movement of the salt was observed at all pressures. This was evidenced by vertical de formation and cavity size reduction.

Introduction

The development of storage techniques for safe disposal of atomic reactor fuel wastes is a goal of the Atomic Energy Commission. Salt domes have been used successfully for storage of liquefied petroleum gases and hence should prove to be suitable for liquid waste products of atomic reactors. The purpose of the following work is to evaluate the practicability of utilizing salt dome cavities for such wastes and to determine particularly the effect of pressure and temperature on a salt cavity. This work represents a part of a comprehensive study covering the over-all problem of storing reactor fuel wastes in salt domes and/or salt beds. The problem of accurately determining the stresses which exist in rocks in the earth's crust is indeed a complex one. Theoretical studies have differed widely in many of the basic assumptions about the physical properties of the rock itself. Some solutions of problems in underground stress analysis assume that rock is elastic, homogeneous and isotropic in character; others assume that rock possesses plastic. viscous, elasticoviscous properties, or a combination thereof. Experimental evidence has shown that sale possesses plastic, viscous and elasticoviscous properties. Recent work has shown that salt becomes more plastic with temperature.
Unsteady-State Liquid Flow Through Porous Media Having Elliptic Boundaries
Authors: Coats K.H. , Tek M.R. , Katz D.L.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 216, 1959, pages 460–464.

Introduction

A large number of boundary value problems encountered in unsteady-state heat transfer, fluid flow through porous media, neutron diffusion and mass transfer involve the solution of a linear, parabolic partial differential equation commonly referred to as the diffusivity equation,

................... (1)

where U is the dependent potential variable, K is the diffusivity (hydraulic, thermal, neutron, etc.) and t is the time variable. Solutions to Eq. 1 are available in the literature for a wide variety of initial and boundary conditions. The great majority of these solutions are obtained for geometric boundaries corresponding to linear, cylindrical or spherical flow models.

A typical engineering application where the solution to Eq. 1 is required is the calculation of underground water encroachment across the boundaries of oil or natural gas reservoirs In this particular area of application, the reservoir boundary is invariably approximated by circular geometry. However, the areal shape of many reservoirs can be better approximated by elliptic rather than circular boundaries. Thus the need for a general method of solving the diffusivity equation in elliptic coordinates arises in this problem as well as in other engineering applications involving elliptic boundaries.

The solution to the diffusivity equation usually involves the Error Function for the linear flow model, Bessel functions for the radial flow model and trigonometric or Legendre functions for the spherical flow model. It is well known that the general solution to the diffusivity equation in elliptic coordinates involves Mathieu functions. The significance of Mathieu functions in the analytical treatment of the diffusivity equation in elliptic coordinates is discussed in the literature. However, these references do not provide analytical solutions useful in practical engineering problems.

The objectives of this paper are the development of the equations describing the unsteady-state liquid flow through a porous medium with an elliptic inner boundary, the development of a numerical method of solving these equations and, finally, a comparison of the water encroachment quantities calculated from the elliptic flow equation with those calculated from the radial flow equation. While the specific problem treated in this paper relates to unsteady-state liquid flow through a porous medium, the basic equations and computational techniques developed will apply equally well to problems occurring in the other areas of engineering interest mentioned previously. The solution given here is limited to a single case in which the outer boundary encloses an area 100 times that of the inner boundary.
Some Practical Aspects of Gravel Packing
Authors: Rodgers C.J.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 201, 1954, pages 41–47.

The present day success of gravel packs to prevent or retard the migration of unconsolidated sands into the well bore is due to:the use of a saline or nonaqueous, nonsolids drill fluid,proper preparation of the well bore prior to gravel packing, andpressure placement of the gravel.

The experience gained from the "pressure pack" method of gravel packing indicates that sand-free fluid production can be maintained for a length of time sufficient to make the operation economically attractive. Data pertaining to the first 15 wells so completed by Gulf indicate that for each dollar spent to effect the completion, there will be a return of more than $2.92.

The pressure pack technique of gravel packing is essentially the placing of gravel in and adjacent to the producing formations. This is done with fluid pressure and by the use of a drill fluid that will permit partial or complete loss of returns to the formation during placement. This technique was first intentionally used by Gulf in May, 1950, and since that time has been applied in more than 90 wells.

Other advantages claimed for this type of completion are that the pressure placement of the gravel has a scouring effect on the casing perforations, that additional drainage channels to the well bore are created, and that the possibility of shifting of the formations adjacent to the casing is minimized and possibly prevented.

Introduction

During the past few years, the use of gravel to prevent or retard the migration of unconsolidated sands into the well bore has met with a favorable degree of success. Numerous methods and techniques of "gravel packing" have been used, each having its own relative merits, and with varying results.
Equilibrium Vaporization Ratios for a Reservoir Fluid Containing a High Concentration of Hydrogen Sulfide
Authors: Vagtborg Harold
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 201, 1954, pages 67–72.

Equilibrium vaporization ratios were obtained for light hydrocarbons, nitrogen, carbon dioxide, and hydrogen sulfide in a reservoir fluid containing 35 mole per cent hydrogen sulfide. The data cover the range from 700 to 2500 psia at 154°F.

The results of this study are compared with results obtained by other investigators on systems containing less hydrogen sulfide. When large amounts of hydrogen sulfide are present, the equilibrium vaporization ratios for ethane and heavier hydrocarbons are greater than the ratios for systems containing little or no hydrogen sulfide. Large amounts of hydrogen sulfide have the reverse effect on the ratios for methane.

Routine PVT studies were performed on the reservoir fluid including flash and differential liberations of the dissolved gas. The pressure-volume relationships of the saturated fluid were also determined.

It is shown that the use of published correlations on physical properties of reservoir fluids can lead to gross errors when applied to systems containing large amounts of hydrogen sulfide.

Introduction

Equilibrium vaporization ratios for various components in naturally occurring crude oil and condensate systems have been reported in the literature. Recently, several papers have been published with emphasis on non-hydrocarbon components such as nitrogen, carbon dioxide and hydrogen sulfide. The increased discovery of reservoir fluids having high concentrations of these non-hydrocarbon components, particularly hydrogen sulfide, has created a need for a further study of their phase behavior.

Equilibrium vaporization ratios are known to vary with pressure, temperature, and overall composition of the system. It was anticipated that ratios for systems containing large amounts of hydrogen sulfide would differ from the ratios for systems containing small amounts of hydrogen sulfide. Therefore, the present work was undertaken in order to obtain reliable equilibrium vaporization ratios for the reservoir-fluid in question.
One-Dimensional, Incompressible, Noncapillary, Two-Phase Fluid Flow in a Porous Medium
Authors: Sheldon J.W. , Cardwell W.T.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 216, 1959, pages 290–296.

Introduction

The fundamental equations that are used to describe two-phase fluid flow in porous media are Darcy's law for each phase and an equation of continuity for each component. The special case of one-dimensional, incompressible, two-phase flow has received much attention in the petroleum engineering literature. The basic paper on the subject is that of Buckley and Leverett. Buckley and Leverett showed that one could eliminate the pressure and obtain a single partial differential equation for the saturation: They solved this equation for the case when gravity and capillary forces are negligible. A frequently encountered property of the solution of the basic partial differential equation is that, as time progresses, the saturation becomes a multiple-valued function of the distance coordinate, x. Buckley and Leverett interpreted the formation of multiple values as an indication that the saturation-distance curve had become discontinuous. They developed a method of determining the position of the discontinuity from a material balance.

We solve the Buckley-Leverett partial differential equation using the method of characteristics and the concept of shocks. Our treatment is analogous to treatments used in the theory of supersonic compressible flow. Although the numerical results obtained are the same as those obtained by previous methods, we believe that this approach is more logical and has broader applicability. It can, for example, be generalized to treat the case when the fluids are compressible. It is not clear how one would go about doing this using the method of Buckley and Leverett. To illustrate the power of the method of characteristics with shocks, we solve a problem in gravity segregation which has not been treated previously in the literature. A special case of the general method developed here was used by Welge to solve a particular fluid displacement problem.

Fundamental Equations

We consider two-phase incompressible flow along the vertical direction x in a porous medium. We assume that there is no flow transverse to x. We measure x positive in the upward direction. The fundamental equations are obtained from Darcy's law and the mass conservation law.
Levels of the health system workforce’s competence and predictors to lead, manage, and govern in northwest Ethiopia
Authors: Ambelie Yeshambel Agumas , Alene Getu Degu , Gebrekiros Damen Hailemariam
Published: February 2020

Aim: The purpose of this study was to determine the levels of competence and predictors to lead, manage, and govern among the health system workforce. Methods: A cross-sectional study was carried out in northwest Ethiopia. Eight hundred thirteen workforce were participated in the study. Competence to lead, manage, and govern was computed from 20 items. It was also leveled into four categories. Ordinal logistic regression analysis was conducted to identify predictors of this competence. Results: From 813 participants, 396 (48.7%) and 582 (71.6%) were females and service owners respectively. The estimates for low, moderate, high and very high levels of competence to lead, manage and govern were 41.3%; 42.7%; 13.5% and 2.5% respectively. Sex (p = .031) and responsibility (p = .019) were identified as main predictors. Conclusions: Competence to lead, manage and govern among the health system workforce in northwest Ethiopia is inadequate. Policymakers, program planners and researchers need to take action giving due attention to females and service owners. Feature research could be conducted considering hierarchical variables.
Busulfan systemic exposure and its relationship with efficacy and safety in hematopoietic stem cell transplantation in children: A Meta-Analysis
Authors: Feng Xinying , Wu Yunjiao , Zhang Jingru , Li Jiapeng , Zhu Guanghua , FAN Duanfang , Yang Changqing , Zhao Libo
Published: February 2020

Background : Busulfan (Bu) is a key component of several conditioning regimens used before hematopoietic stem cell transplantation (HSCT). However, the optimum systemic exposure (expressed as the area under the concentration-time curve [AUC]) of Bu for clinical outcome in children is controversial. Methods : Research on pertinent literature was carried out at PubMed, EMBASE, ClinicalTrials.gov and the Cochrane Library. Observational studies were included, which compared clinical outcomes above and below the area under the concentration-time curve (AUC) cut-off value, which we set as 800, 900, 1000, 1125, 1350, and 1500 µM × min. The primary efficacy outcome was notable in the rate of graft failure. In the safety outcomes, incidents of veno-occlusive disease (VOD) were recorded, as well as other adverse events. Results : Thirteen studies involving 548 pediatric patients (aged 0.3-18 years) were included. Pooled results showed that, compared with the mean Bu AUC (i.e., the average value of AUC measured multiple times for each patient) of > 900 µM × min, the mean AUC value of <900 µM × min significantly increased the incidence of graft failure (RR=3.049, 95% CI: 1.285-7.234). The incidence of VOD was significantly decreased with the mean AUC <1350 µM × min (RR=0.370, 95% CI: 0.205-0.666) and <1500 µM × min (RR=0.409, 95% CI: 0182-0.920). Conclusions : In children, Bu mean AUC above the cut-off value of 900 µM × min (after every 6-hour dosing) was associated with decreased rates of graft failure, while the cut-off value of 1350 µM × min were associated with increased risk of VOD in children, particularly for the patients without VOD prophylaxis therapy. Further well-designed prospective and multi centric randomized controlled trials with larger sample size are necessary before putting our result into clinical practices.
Solidarity, Vulnerability and Mistrust: How Context, Information and Government Affect the Lives of Women in Times of Zika
Authors: Arias Ana Rosa Linde Linde , Roura Maria , Siqueira Eduardo
Published: February 2020

Background
The public health response to Zika outbreak has mostly focused on epidemiological surveillance, vector control, and individual level preventative measures. This qualitative study employs a social-ecological framework to examine how macro (historical, legislative, political, socio-economic factors), meso (sources of information, social support, social mobilization) and micro level factors ( i ndividual actions, behavioral changes) interacted to influence the response and behavior of women with respect to Zika in different contexts.
Methods
A qualitative study was carried out. Women were recruited through the snowball sampling technique from various locations in Brazil, Puerto Rico, and the United States. They were of different nationalities and ethnicities. Data were collected through semi-structured interviews. The data transcripts were analyzed using thematic analysis.
Results
Women in this study deemed the information provided as insufficient, which led them to actively reach out and access a variety of media sources. Social networks played a vital role in sharing information but also resulted in the spread of hoaxes or rumors. Participants in our research perceived socio-economic inequities but focused on how to remedy their microenvironments. They did not engage in major social activities. Lack of trust in governments placed women in vulnerable situations by preventing them to follow the guidance of health authorities. These impacts were also a result of the response tactics of health and government administrations in their failed attempts to ensure the well-being of their countries’ populations.
Conclusions
Our findings call for a broad spectrum of public health interventions that go beyond individual level behavioral change campaigns, to more comprehensively address the broader meso and macro level factors that influence womens’ willingness and possibility to protect themselves.
Key words : Zika, women, social determinants, information, public health, maternal and child health
Asiatic acid attenuates hypertrophic and fibrotic differentiation of articular chondrocytes via AMPK/PI3K/AKT signaling pathway
Authors: Liu Na , Fu Dejie , Yang Junjun , Liu Pingju , Song Xiongbo , Wang Xin , Li Rui , Fu Zhenlan , Chen Jiajia , Gong Xiaoyuan , Chen Cheng , Yang Liu
Published: February 2020

Background: Osteoarthritis (OA), the most common joint disorder, is characterized by a progressive degradation of articular cartilage. Increasing evidence suggests that OA is closely associated with cartilage pathologies including chondrocyte hypertrophy and fibrosis. Methods: In this study, we showed that asiatic acid (AA) treatment reduced chondrocyte hypertrophy and fibrosis. First, the cytotoxicity of AA (0, 5, 10, and 20 μM) to chondrocytes was evaluated, and 5 μM was selected for subsequent experiments. Then, we detected the gene and protein level of chondrocyte hypertrophic markers including type X collagen (COL-X), matrix metalloproteinase - 13 (MMP-13), alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2), and chondrocyte fibrosis markers including type I collagen (COL-Ι) and alpha-smooth muscle actin (α-SMA), and chondrogenic markers including SRY-related HMG box 9 (SOX9), type II collagen (COL-II) and aggrecan (ACAN). Further, we tested the mechanism of AA on inhibiting chondrocyte hypertrophy and fibrosis. Finally, we verified the results in an anterior cruciate ligament transection (ACLT) rat OA model.Results: We found that AA treatment inhibited the hypertrophic and fibrotic phenotype of chondrocytes, without affecting the chondrogenic phenotype. Moreover, we found that AA treatment activated AMP-activated protein kinase (AMPK) and inhibited phosphoinositide-3 kinase/protein kinase B (PI3K/AKT) signaling pathway in vitro. The results in an ACLT-rat OA model also indicated that AA significantly attenuated chondrocyte hypertrophy and fibrosis. Conclusion: AA treatment could reduce hypertrophic and fibrotic differentiation, and maintain the chondrogenic phenotype of articular chondrocytes by targeting the AMPK/PI3K/AKT signaling pathway. Our study suggested that AA might be a prospective drug component that targets hypertrophic and fibrotic chondrocytes for OA treatment.
MHC associations of ankylosing spondylitis in East Asians are complex and involve non-HLA-B27 HLA contributions
Authors: Wang Geng , Kim Tae-Hwan , Li Zhixiu , Cortes Adrian , Kim Kwangwoo , Bang So-Young , Leo Paul , Brown Matthew , Xu Huji
Published: February 2020

Background The association of HLA-B*27 with AS is amongst the strongest of any known association of a common variant with any human disease. Nonetheless, there is strong evidence indicating that other HLA-B alleles are involved in the disease. Large studies in European case-control cohorts have demonstrated risk associations with HLA-B*40 and multiple other HLA-B, -A and Class II alleles, and demonstrated that in that ethnic group the amino acid sequence at position 97 in HLA-B is the key determinant of HLA associations with AS. A recent study in Korean AS cases and controls additionally identified association at HLA-C*15:02. In the current study we examined the MHC associations of AS in an expanded east Asian cohort. Methods 1,637 Chinese, Taiwanese and Korean AS cases meeting the modified New York Criteria for AS, and 1,589 ethnically matched controls, were genotyped with the Illumina Immunochip, including a dense coverage of the MHC region. HLA genotypes and amino acid composition was imputed using the SNP2HLA program using the Han-MHC reference panel based on the data of Han Chinese subjects (largest Asian MHC reference available (n= 9,689)), and association tested using logistic regression using 10 principal components to control for population stratification effects. Results Strong association was seen with HLA-B*27 (odds ratio (OR) =205.3, P=5.764×10 -244 ). Controlling for this association, the strongest risk association is seen with HLA-C*15 at genome-wide significant level (OR = 7.62, P=9.30×10 -19 ), and confirmed association is also seen with HLA-B*40 at suggestive level (OR= 1.65, P= 2.54x10 -4 ). At amino acid level the strongest association seen in uncontrolled analysis was with histidine at position 114 in HLA-B (p=7.24 x10 -241 ), but conditional analyses suggest that the primary amino acid associations are with lysine at position 70 and asparagine at position 97. Restriction of the ERAP1 association with HLA-B27-positive AS, previously reported in European subjects, was confirmed in East Asians. Conclusions This study confirms in East Asians that the HLA associations of AS are multiple, including previously reported associations at HLA-B*27, -B*40, -C*15 , and –DRB1*01 , as well as novel associations with –DRB1*13 and –B*39 . The HLA-B associations are driven by the amino acids at positions 70 and 97, in the B-pocket of HLA-B.
Prevalence and associated factors of musculoskeletal disorders among working adults in Ethiopia: a systematic review protocol
Authors: Gebreyesus Tsiwaye , Janakiraman Balamurugan , Nigussie Kalkidan
Published: February 2020

Background: Musculoskeletal disorders among the working population are a major public health problem, resulting in significant personal and national economic loss. Yet there is a lack of consensus estimates of the prevalence of musculoskeletal disorders among the working population in Ethiopia. This systematic review and meta-analysis will provide the pooled prevalence of musculoskeletal disorders and its determinant factors among the adult working population in Ethiopia.Method: The electronic databases MEDLINE, PubMed, CINAHL, Science Direct index, SCOPUS, PEDro, and Google Scholar will be systematically searched. In addition, the grey literature resources such as databases or websites of dissertations and theses will be searched. The reference list of screened articles will also be hand searched. All observational studies reporting on the prevalence of work-related musculoskeletal pain of any bodily region among adult Ethiopians will be included. Random and quality effects models will be used to calculate pooled prevalence with a 95 % confidence interval. Subgroup and sensitivity analyses will be performed. Publication bias and heterogeneity between the included studies will also be assessed and reported.Discussion: The proposed systematic review and meta-analysis will provide valid insight into the pooled prevalence of multi-regional work-related musculoskeletal pain and factors associated to assist policymakers in occupational health and health care sectors. And further, we strongly believe that the data will also immensely help the understanding of the factors associated and in developing work exposure implementations,and prevention programs in workplaces.
Protection effect of gastrodin on learning and memory ability in vascular dementia by promoting autophagy flux via Ca2+/CaMKII signal pathway
Authors: chen Ting ting , zhou Xue , xu Yi ni , wu Xiao ying , xiang Quan , fu Ling yun , hu Xiao xia , tao Ling , shen Xiang chun
Published: February 2020

Background: Vascular dementia is a common and frequently-occurring disease in the process of human aging. Although the current treatment can delay the deterioration of the disease, it has not a great breakthrough in improving cognitive impairment. Therefore, exploring the potential key molecular targets of VD provide promising strategy for prevention and treatment. Methods: vascular dementia rats were reproduced by permanent middle cerebral artery occlusion (pMCAO) and anoxic injury of HT22 cells were induced by Cobalt Chloride (CoCl 2 , 200μM). The ability of spatial learning and memory was assessed by morris water maze (MWM) test. Histological analysis was performed by HE staining and immunohistochemical staining. The effects of gastrodin on autophagy flux and calcium signal in vascular dementia rats and HT22 cells during hypoxia injury were detected by Western blotting and immunofluorescence. Furthermore, intracellular Ca 2+ levels were quantified using a Ca 2+ quantification kit and were also measured by flow cytometric estimation of Fluo-4 AM. Results: Gastrodin significantly reversed cognitive deficits in vascular dementia rats. The results of immunohistochemical analysis and western blot confirmed that gastrodin could attenuate the levels of LC3, p62 and phosphorylated CaMKII in hippocampus of VD rats. In addition, gastrodin was similar to the early autophagic inhibitor (3-BDO) ameliorating CoCl 2 -induced autophagic flux dysfunction and p62 knockdown by siRNA also promoting autophagic flux patency, but the late autophagy inhibitor (CQ) weakened the improvement effect of gastrodin. Furthermore, gastrodin markedly inhibited CoCl 2 -induced autophagic flux dysfunction by inhibiting [Ca 2+ ] i -dependent CaMKII. Conclusion: Gastrodin is a potential promising candidate for VD by improving autophagy flux dysfunction via increasing lysosome acidification and autophagosome-lysosome fusion mediated by CaMKII-regulated suppression of p62 signaling. Keywords: Gastrodin, Vascular dementia, Neuron injury, Autophagic flux, Ca 2+ , CaMKII
Spatiotemporal association of low birth weight with Cs-137 deposition after Fukushima at the prefecture level in Japan: an ecological study
Authors: Scherb Hagen , Clinic Japan Hayashi Osaka Keiji Hayashi Children's
Published: February 2020

Background: Perinatal mortality increased in contaminated prefectures after the Fukushima Daichi Nuclear Power Plant (FDNPP) accidents in Japan in 2011. Elevated numbers of surgeries for cryptorchidism and congenital heart malformations were observed throughout Japan from 2012 onward. The thyroid cancer detection rate (2011 to 2016) was associated with the dose-rate at the municipality level in the Fukushima prefecture. Since the birth weight is a simple and objective indicator for gestational development and pregnancy outcome, the question arises whether the annual birth weight distribution was distorted in a dose-rate-dependent manner across Japan after Fukushima. Data and Methods: The Japanese Ministry of Health, Labour, and Welfare provides prefecture-specific annual counts for 26.158 million live births from 1995 to 2018, of which 2.366 million births (9.04%) with weights < 2500g. Prefecture-specific spatiotemporal trends of the low birth weight proportions were analyzed. Logistic regression allowing for level-shifts from 2012 onward was employed to test whether those level-shifts were proportional to the prefecture-specific dose-rates derived from Cs-137 deposition in the 47 Japanese prefectures. Results: The overall trend of the low birth weight proportion (LBWp) in Japan discloses a jump in 2012 with a jump odds ratio (OR) 1.020, 95%-confidence interval (1.003,1.037), p-value 0.0225. A logistic regression of LBWp on the additional dose-rate after Fukushima adjusted for prefecture-specific spatiotemporal base-line trends yields an OR per µSv/h of 1.098 (1.058, 1.139), p-value < 0.0001. Further adjusting the logistic regression for the annual population size and physician density of the prefectures, as well as for the counts of the dead, the missing, and the evacuees due to earthquake and tsunami (as surrogate measures for medical infrastructure and stress) yields an OR per µSv/h of 1.109 (1.032, 1.191), p-value 0.0046. Conclusion: This study shows increased low birth weight prevalence related to Cs-137 deposition and the corresponding additional dose-rate in Japan from 2012 onward. Previous evidence suggesting compromised gestational development and pregnancy outcome under elevated environmental ionizing radiation exposure is corroborated.
Effect of ambient temperature on incidence of tuberculosis and effect modification by meteorological factors in Jinan, China during 2012-2015
Authors: Ye Runze , Cui Liangliang , Zhou Jingwen , Wang Meihua , Jia Chongqi , Ruan Shiman
Published: February 2020

ObjectiveFor assessing the nonlinearity and delayed effect of temperature on incidence of Tuberculosis (TB) and effect modification by meteorology factors, daily data on meteorological factors, air pollutants and incidence were obtained in Jinan, China, from 2012 to 2015.MethodsA distributed lag non-linear model (DLNM) combined with quasi-Poisson regression model was employed to assess the nonlinearity and the delayed effect of associations. We further built a series of weather-stratified models categorizing the meteorology factors into two levels to assess the effect modification of the ambient temperature effect. ResultsThe correlation between tuberculosis (TB) cases and daily average temperature (Tmean) was nonlinear with a delayed effect. At the current day (lag 0), the increase of Tmean decreased the risk of TB incidence; over lag 0-70 days, the decrease of low Tmean and the increase of the high Tmean both indicated the increased risk of TB. The cold temperature showed an immediate effect at the current day, with a harvesting effect in the following days. There was no significant harvesting effect in hot effect. Meanwhile, the effect of hot temperature on TB appeared with an about two-week lag and was lower than cold effect. The effect modifications by relative humidity, wind speed and sunshine duration were observed.ConclusionResults indicate that there was a nonlinear correlation with a harvesting effect between temperature and TB in Jinan, and both cold effect and heat effect exist the delayed effect. Results also pointed to the importance of considering effect modification by meteorological factors in assessing temperature effects on incidence of TB. Which might shed light on the strategy of TB prevention and control.
The effect of using awake craniotomy combined with multimodal techniques intraoperative on survival of patients with glioblastoma: a single-center experience
Authors: zhou hui , Yang Li , Lu Ming , Deng Xqing , Yang Mming
Published: February 2020

Background :We analysed outcomes of cerebral glioblastoma patients undergoing awake craniotomies combined with multimodal techniques for tumour resection, with regards to the extent of resection, functional preservation, and prognosis. Methods : A retrospective analysis was conducted on adult glioblastoma patients who underwent an awake craniotomy from September 2010 to August 2018 under anaesthesia combined with multimodal techniques. Results: In total, 81 glioblastoma patient charts were analysed. The most common lesion sites were the frontal lobe (n=36), temporal lobe (n=17), and parietal lobe (n=6). The main symptoms were headache (n=51), dyskinesia (n=11), speech disorder (n=9), and epilepsy (n=10). The extent of resection was gross total for 91.36% patients, subtotal for 7.41%, and partial for 1.23%. No deaths occurred 30 days post-operation. Intracranial haemorrhage occurred in 2 patients, seizures in 5 patients, and intracranial infections in 3 patients. There was no significant difference between preoperative and postoperative Karnofsky Performance Status scores (P>0.05). There were no significant changes in postoperative neurological function in 50 patients. Symptoms improved in 24 patients. Three patients exhibited motor dysfunction, 2 exhibited speech deficits, and 2 exhibited sensory deficits. The average duration of hospitalization was 6.89±2.66 days. The shortest survival time was 4 months, the longest survival time was 26 months, and the median survival time was 12 months. Conclusions: Awake craniotomy using multimodal techniques such as neuronavigation, intraoperative ultrasound, electrophysiology, and tumour fluorescence during an operation can maximize safety during the cerebral glioblastoma resection, thus protecting brain function and improving surgical efficacy and patients’ postoperative quality of life.
Correlation between exposure to fine particulate matter and hypertensive disorders of pregnancy in Shanghai, China
Authors: Su Xiujuan , Zhao Yan , Yang Yingying , Hua Jing
Published: February 2020

Background Association between fine particulate matter (PM 2.5 ) and hypertensive disorders of pregnancy (HDP) is inconsistent and appears to change in each trimester. We aim to investigate the association of exposure to ambient PM 2.5 in early pregnancy with HDP. A retrospective cohort study was performed among 8,776 women with singleton pregnancy who attended the antenatal clinic before 20 gestational weeks in a tertiary women’s hospital during 2014 - 2015. Land use regression models were used to predict individual levels of PM 2.5 exposure. Results The average PM 2.5 concentration during the first 20 gestational weeks ranged from 28.6 to 74.8 μg m -3 [median, 51.4 μg m -3 ; interquartile range, 47.3 - 57.8 μg m -3 ]. A total of 440 (5.0%) women was diagnosed with HDP. The restricted cubic spline showed an exposure-response relationship between the PM 2.5 concentration and risk of HDP. We observed an association between PM 2.5 exposure during the first trimester with HDP (RR = 3.89 per 10 μg m -3 , 95% CI: 1.45 - 10.43), but not during the second trimester (RR = 0.71 per 10 μg m -3 , 95% CI: 0.40 - 1.27). Compared with their counterparts, nulliparous women who were exposed to high levels of PM 2.5 in the index pregnancy had a higher risk of developing HDP [the relative excess risk due to interaction was 0.92 (0.46 - 1.38)]. Conclusion Our findings suggest that PM 2.5 exposure during the first trimester is associated with the development of HDP, and the association is modified by parity.
Development of a tool for identifying and addressing prioritised determinants of quality improvement projects led by healthcare professionals: a mixed-methods study
Authors: Tuijl Anne van , Wollersheim Hub C. , Fluit Cornelia R.M.G. , Gurp Petra. J. van , Calsbeek Hiske
Published: February 2020

Background Several frameworks have been developed to identify essential determinants for healthcare improvement. These frameworks aim to be comprehensive, leading to the creation of long lists of non-prioritised determinants. Furthermore, most existing frameworks do not describe the methods or actions used to identify and address the determinants, limiting their practical value. The aim of this study is to describe the development of a tool to determine the prioritised facilitators and barriers for healthcare improvement projects led by healthcare professionals, supplemented with methods to identify and address each determinant. Methods A mixed-methods study design was used to develop the tool. First, a cross-sectional study was performed, using an online survey to ask healthcare professionals about the determinants they experienced during the performance of their quality improvement project. A priority score was calculated for every named determinant, and those with a priority score ≥ 20 were incorporated into the tool. Semi-structured interviews with implementation experts determined: 1) how healthcare professionals can be assisted to use our tool to analyse the determinants in their project and 2) how healthcare professionals can tackle the barriers or use the facilitators identified in their quality improvement project. Results The 25 healthcare professionals in this study experienced 64 facilitators and 66 barriers when performing their improvement projects. Of these, 12 facilitators and nine barriers were incorporated into the tool. Sufficient support from management of the department was identified as the most important facilitator, while having limited time to perform the project was considered the biggest barrier. The interviews with 16 experts in implementation science led to various inputs for better identifying and addressing each determinant. Important themes included maintaining adequate communication with stakeholders, keeping the project at a manageable size, learning by doing and being able to influence determinants. Conclusions This paper describes a tool for performing quality improvement projects in healthcare, with the barriers and facilitators that were considered most important by healthcare professionals. For each of these barriers and facilitators, suggestions on how to analyse and address the determinant are given. More research is needed to validate and develop the tool further.
The effectiveness of application of the standardized terminology for telephone follow-up model in discharge follow-up of patients with cancer pain.
Authors: PENG Xin , ZHANG Xing , REN Yi , XIONG juan li
Published: February 2020

Purpose This article aims to explore a standardized telephone follow-up model for patients with cancer pain, thus to promote standardized management of discharge follow-up of the patients with cancer pain.Method We have developed a flow chart of standard terminology for discharge follow-up of the patients with cancer pain. The 80 patients with cancer pain who have discharged from our hospital were divided into the control group (40 cases) and the observation group (40 cases), both groups were followed up by telephone within one week of discharge. The pain nurses have done the discharge follow up by telephone using the communication method of routine follow-up and the communication method of standardized terminology, self-monitoring, treatment compliance, adverse reaction management, self-management ability and satisfaction with telephone follow-up were compared between the two groups. Results The total scores of self-pain monitoring, treatment compliance, adverse reaction management and self-management ability in the observation group were higher than those in the control group (P<0.05). The satisfaction of the observation group was significantly higher than that of the control group (P<0.05).Conclusion The application of the standardized terminology telephone follow-up mode can promote effective communication between nurses and patients, standardize the process and content of telephone follow-up. It can effectively improve the effectiveness of telephone follow-up and the satisfaction of patients with nursing services, which is suitable for clinical reference.