22 research outputs found
New relations for Einstein–Yang–Mills amplitudes
No full textAbstractWe obtain new relations between Einstein–Yang–Mills (EYM) amplitudes involving N gauge bosons plus a single graviton and pure Yang–Mills amplitudes involving N gauge bosons plus one additional vector boson inserted in a way typical for a gauge boson of a “spectator” group commuting with the group associated to original N gauge bosons. We show that such EYM amplitudes satisfy U(1) decoupling relations similar to Kleiss–Kuijf relations for Yang–Mills amplitudes. We consider a D-brane embedding of EYM amplitudes in the framework of disk amplitudes involving open and closed strings. A new set of monodromy relations is derived for mixed open–closed amplitudes with one closed string inserted on the disk world-sheet and a number of open strings at the boundary. These relations allow expressing the latter in terms of pure open string amplitudes and, in the field-theory limit, they yield the U(1) decoupling relations for EYM amplitudes
Aldosterone antagonists in addition to renin angiotensin system antagonists for preventing the progression of chronic kidney disease
No full textBackground: Treatment with angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) is used to reduce proteinuria and retard the progression of chronic kidney disease (CKD). However, resolution of proteinuria may be incomplete with these therapies and the addition of an aldosterone antagonist may be added to further prevent progression of CKD. This is an update of a Cochrane review first published in 2009 and updated in 2014. Objectives: To evaluate the effects of aldosterone antagonists (selective (eplerenone), non-selective (spironolactone or canrenone), or non-steroidal mineralocorticoid antagonists (finerenone)) in adults who have CKD with proteinuria (nephrotic and non-nephrotic range) on: patient-centred endpoints including kidney failure (previously know as end-stage kidney disease (ESKD)), major cardiovascular events, and death (any cause); kidney function (proteinuria, estimated glomerular filtration rate (eGFR), and doubling of serum creatinine); blood pressure; and adverse events (including hyperkalaemia, acute kidney injury, and gynaecomastia). Search methods: We searched the Cochrane Kidney and Transplant Register of Studies up to 13 January 2020 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal, and ClinicalTrials.gov. Selection criteria: We included randomised controlled trials (RCTs) and quasi-RCTs that compared aldosterone antagonists in combination with ACEi or ARB (or both) to other anti-hypertensive strategies or placebo in participants with proteinuric CKD. Data collection and analysis: Two authors independently assessed study quality and extracted data. Data were summarised using random effects meta-analysis. We expressed summary treatment estimates as a risk ratio (RR) for dichotomous outcomes and mean difference (MD) for continuous outcomes, or standardised mean difference (SMD) when different scales were used together with their 95% confidence interval (CI). Risk of bias were assessed using the Cochrane tool. Evidence certainty was evaluated using GRADE. Main results: Forty-four studies (5745 participants) were included. Risk of bias in the evaluated methodological domains were unclear or high risk in most studies. Adequate random sequence generation was present in 12 studies, allocation concealment in five studies, blinding of participant and investigators in 18 studies, blinding of outcome assessment in 15 studies, and complete outcome reporting in 24 studies. All studies comparing aldosterone antagonists to placebo or standard care were used in addition to an ACEi or ARB (or both). None of the studies were powered to detect differences in patient-level outcomes including kidney failure, major cardiovascular events or death. Aldosterone antagonists had uncertain effects on kidney failure (2 studies, 84 participants: RR 3.00, 95% CI 0.33 to 27.65, I2 = 0%; very low certainty evidence), death (3 studies, 421 participants: RR 0.58, 95% CI 0.10 to 3.50, I2 = 0%; low certainty evidence), and cardiovascular events (3 studies, 1067 participants: RR 0.95, 95% CI 0.26 to 3.56; I2 = 42%; low certainty evidence) compared to placebo or standard care. Aldosterone antagonists may reduce protein excretion (14 studies, 1193 participants: SMD -0.51, 95% CI -0.82 to -0.20, I2 = 82%; very low certainty evidence), eGFR (13 studies, 1165 participants, MD -3.00 mL/min/1.73 m2, 95% CI -5.51 to -0.49, I2 = 0%, low certainty evidence) and systolic blood pressure (14 studies, 911 participants: MD -4.98 mmHg, 95% CI -8.22 to -1.75, I2 = 87%; very low certainty evidence) compared to placebo or standard care. Aldosterone antagonists probably increase the risk of hyperkalaemia (17 studies, 3001 participants: RR 2.17, 95% CI 1.47 to 3.22, I2 = 0%; moderate certainty evidence), acute kidney injury (5 studies, 1446 participants: RR 2.04, 95% CI 1.05 to 3.97, I2 = 0%; moderate certainty evidence), and gynaecomastia (4 studies, 281 participants: RR 5.14, 95% CI 1.14 to 23.23, I2 = 0%; moderate certainty evidence) compared to placebo or standard care. Non-selective aldosterone antagonists plus ACEi or ARB had uncertain effects on protein excretion (2 studies, 139 participants: SMD -1.59, 95% CI -3.80 to 0.62, I2 = 93%; very low certainty evidence) but may increase serum potassium (2 studies, 121 participants: MD 0.31 mEq/L, 95% CI 0.17 to 0.45, I2 = 0%; low certainty evidence) compared to diuretics plus ACEi or ARB. Selective aldosterone antagonists may increase the risk of hyperkalaemia (2 studies, 500 participants: RR 1.62, 95% CI 0.66 to 3.95, I2 = 0%; low certainty evidence) compared ACEi or ARB (or both). There were insufficient studies to perform meta-analyses for the comparison between non-selective aldosterone antagonists and calcium channel blockers, selective aldosterone antagonists plus ACEi or ARB (or both) and nitrate plus ACEi or ARB (or both), and non-steroidal mineralocorticoid antagonists and selective aldosterone antagonists. Authors' conclusions: The effects of aldosterone antagonists when added to ACEi or ARB (or both) on the risks of death, major cardiovascular events, and kidney failure in people with proteinuric CKD are uncertain. Aldosterone antagonists may reduce proteinuria, eGFR, and systolic blood pressure in adults who have mild to moderate CKD but may increase the risk of hyperkalaemia, acute kidney injury and gynaecomastia when added to ACEi and/or ARB
Verification of Design Equations for Ductile Failure Mode in Bolted Connections of Local Hardwoods.
No full textReferring to the Malaysian Timber Standard (MS544: Part 5: 2001), it should be capable in estimating the bolted connection capacity for bearing failure as the development of the code is based on the ductile failure mode. However, in the previous research studies conducted by the author on bolted joints of local hardwoods such as Meraka, Belian and Selangan Batu, it was found that the code provides too conservative design strength values. This can lead to an uneconomical wall-diaphragm connection retrofit design for the unreinforced masonry buildings because of more fabrication of steel in the design output is produced due to the increment of the number or size of bolts. Thus, this present experimental study was performed in an effort to extend the use of European Yield Model (EYM) in predicting the bolted connections for local Kapur hardwood. From the comparison made between the laboratory data and EYM, the potential of the design equation was verified
Incidence and Outcomes of COVID-19 in People With CKD: A Systematic Review and Meta-analysis.
No full textRationale & Objective: Coronavirus disease
2019 (COVID-19) disproportionately affects
people with chronic diseases such as chronic
kidney disease (CKD). We assessed the incidence
and outcomes of COVID-19 in people
with CKD.
Study Design: Systematic review and metaanalysis
by searching MEDLINE, EMBASE, and
PubMed through February 2021.
Setting & Study Populations: People with CKD
with or without COVID-19.
Selection Criteria for Studies: Cohort and casecontrol
studies.
Data Extraction: Incidences of COVID-19,
death, respiratory failure, dyspnea, recovery,
intensive care admission, hospital admission,
need for supplemental oxygen, hospital
discharge, sepsis, short-term dialysis, acute
kidney injury, and fatigue.
Analytical Approach: Random-effects metaanalysis
and evidence certainty adjudicated
using an adapted version of GRADE (Grading
of Recommendations Assessment, Development
and Evaluation).
Results: 348 studies (382,407 participants with
COVID-19 and CKD; 1,139,979 total
participants with CKD) were included. Based
on low-certainty evidence, the incidence of
COVID-19 was higher in people with CKD
treated with dialysis (105 per 10,000 personweeks;
95% CI, 91-120; 95% prediction
interval [PrI], 25-235; 59 studies; 468,233
participants) than in those with CKD not
requiring kidney replacement therapy (16 per
10,000 person-weeks; 95% CI, 4-33; 95% PrI,
0-92; 5 studies; 70,683 participants) or in
kidney or pancreas/kidney transplant recipients
(23 per 10,000 person-weeks; 95% CI, 18-30;
95% PrI, 2-67; 29 studies; 120,281
participants). Based on low-certainty evidence,
the incidence of death in people with CKD and
COVID-19 was 32 per 1,000 person-weeks
(95% CI, 30-35; 95% PrI, 4-81; 229 studies;
70,922 participants), which may be higher than
in people with CKD without COVID-19
(incidence rate ratio, 10.26; 95% CI, 6.78-
15.53; 95% PrI, 2.62-40.15; 4 studies; 18,347
participants).
Limitations: Analyses were generally based on
low-certainty evidence. Few studies reported
outcomes in people with CKD without COVID-
19 to calculate the excess risk attributable to
COVID-19, and potential confounders were not
adjusted for in most studies.
Conclusions: The incidence of COVID-19
may be higher in people receiving
maintenance dialysis than in those with
CKD not requiring kidney replacement
therapy or those who are kidney or
pancreas/kidney transplant recipients.
People with CKD and COVID-19 may have
a higher incidence of death than people
with CKD without COVID-19
Load carrying capacity of multiple fastener steel to bamboo joints loaded parallel to the fibre direction
No full textLaminated bamboo could be a promising material when it comes to large span roofing structures where often truss structures are adopted. It is assumed that connection design used for timber trusses can also be applied in laminated bamboo trusses. For this research truss nodes with slotted-in steel plates are considered. This research will focus itself on the effect of using multiple fasteners in a row in laminated bamboo connections with a single slotted-in steel plate. As a starting point, the possible failure modes and methods for predicting the load-bearing capacity of a single fastener timber connection are assumed to be also applicable to laminated bamboo. Timber can show ductile and brittle failure modes. Ductile failure modes are described by the European Yield Model (EYM) which was first published by Johansen in 1949. Three different failure modes can be distinguished in the EYM, where mode 1 represents pure embedment failure, mode 2 is failure due to one plastic hinge in the fastener per shear plane and mode 3 shows two plastic hinges per shear plane. The brittle failure modes that can be distinguished are splitting, shear plug, tension failure of the net section and group tear-out. The capacity of a multiple fastener connection might not equal the capacity of a single fastener connection multiplied by the number of fasteners. The main parameters that might influence the load-carrying capacity of multiple fastener joints are the inaccuracies in manufacturing, fastener spacing and end distances, dowel slenderness ratio and the plastic behaviour of the fastener. The testing methods for determining the strength en deformation characteristics of laterally loaded connections with dowels in load-bearing timber structures are used for this research. The objective is to study the influence of the number of fasteners in one row on the load carrying capacity of a steel to laminated bamboo connection. The design of the test pieces is based on the European Yield Model (EYM) where three different failure modes can be distinguished. In order to accomplish this, 9 test series are performed with a variation in the number of fasteners in one row (i.e. 1, 2 and 3) and a variation in thickness of the laminated bamboo members (i.e. 15 mm, 43 mm and 90 mm). The test results show that laminated bamboo connections with a slotted-in steel plate and thin bamboo members have limited deformation capacity and tend to show premature brittle failure due to a shear plug. A clear plastic branch in the load slip diagram of the test series where a single fastener and a member thickness of 15 mm is used, indicates that there is some amount of embedment prior to fracture. In case of two dowels in a row this plastic branch shortens and in case of three dowels in a row no plastic behaviour was observed. The limited deformation capacity of these type of joints (especially when multiple dowels in a row are used) makes the applicability of the EYM for a laminated bamboo connection where failure mode 1 is governing questionable. Plastic hinges did develop in the dowels in the test variants where failure mode 2 and 3 was expected. the EYM can quite accurately predict the capacity of a double shear laminated bamboo joint with a central steel plate where the dowel slenderness ratio is sufficient to achieve failure mode 2 or 3. The effective number of fasteners in a laminated bamboo connection was found to be higher than predicted with the equation given in EC5 irrespective of the observed failure mode. It is because of the decrease in deformation capacity that the load per dowel in a multiple fastener connection is lower than in a connection with a single fastener. The nef for laminated bamboo and several wood species was found to be in the same order of magnitude for a connection with three dowels in a row. The joint stiffness per dowel of a laminated bamboo connection with a slotted-in steel plate was found to decrease with increasing number of fasteners in a row. It also seems that the joint stiffness is higher in case of failure mode 2 and 3 than in case of failure mode 1.Civil Engineering and GeosciencesStructural Engineerin
Automatic Segmentation For Visual Inspection In Semiconductor Manufacturing Using Multiscale Morphology
No full textEctopic expression of Hoxb3 in the second branchial arch leads to abnormal craniofacial development
No full textCraniofacial morphogenesis is orchestrated through molecular interactions
between heterogeneous populations of cells in the branchial arches. To
understand how Hoxb3 acts in concert with other genes in specifying
hindbrain rhombomere and branchial arch identity, we created a gain-offunction
mouse mutant using a Hoxb2 rhombomere 4 and second branchial
arch specific enhancer element. The mutant mice, named SL2, displayed
various craniofacial abnormalities including pointed face, impaired whisker
movement, facial paralysis, impaired reaching response and abnormal
circling behaviour.
The SL2 transgenic mutants have smaller second branchial arches. Skeletal
staining showed a partial or complete loss of middle and inner ear
structures, most notably the lack of tympanic ring and stapes; the
morphology of the mandible and squamous bone were abnormal. In the
SL2 mutant, although Hoxb3 is ectopically expressed only in the second
arch, both first and second arch-derived structures are affected. We
hypothesize that mis-patterned second arch derived cells may affect first
arch derived structures during morphogenesis.
We found that ectopic expression of Hoxb3 in the second branchial arch
resulted in altered expression domains of genes in both first and second
branchial arches. In 9.5 and 10.5 dpc embryos, the expression domains of
genes involved in the ET1/EdnrA signalling pathway including Gsc,
dHAND, Prx2 and Dlx5 were all affected in SL2 mutants. By contrast, the
expression domains of genes involved in Bmp and Fgf signaling pathways
including Bmp4, Msx1 and Spry1 remain unchanged. Therefore, it is
possible that Hoxb3 is specifically involved in the ET1/EdnrA pathway
during branchial arch patterning.link_to_subscribed_fulltextThe 15th International Society of Developmental Biologist Congress 2005, Sydney, Australia, 3-7 September 2005. In Mechanisms of Development, 2005, v. 122 n. Suppl. 1, p. S88-S89, abstract no. 03-P04
Hoxb3 is involved in the endothelin-1 signaling pathway in patterning the facial branchial arches
No full text
