A postpartum woman diagnosed with multiple vertebral fragility fractures due to pregnancy and lactation-associated osteoporosis

Pregnancy and lactation-associated osteoporosis (PLO) is a rare condition diagnosed with vertebral fractures detected in late pregnancy and early postpartum periods. The incidence of PLO is reported to be 0.4 in 100 000 women. Maternal bone resorption and absorption of calcium from the intestines are increased in order to ensure adequate calcium transfer to the fetus, 80% of which is in the last trimester. Bone mineral density decreases during lactation and is associated with high bone turnover. Although various factors have been suggested to be responsible, the cause and etiopathogenesis of osteoporosis associated with pregnancy and lactation have not been fully elucidated. Herein, we reported a 28 year-old primigravid woman without risk factors for secondary osteoporosis diagnosed with vertebral fractures at postpartum third month

The frequency of Duchenne muscular dystrophy/Becker muscular dystrophy and Pompe disease in children with isolated transaminase elevation: results from the observational VICTORIA study

IntroductionElevated transaminases and/or creatine phosphokinase can indicate underlying muscle disease. Therefore, this study aims to determine the frequency of Duchenne muscular dystrophy/Becker muscular dystrophy (DMD/BMD) in male children and Pompe disease (PD) in male and female children with isolated hypertransaminasemia.MethodsThis multi-center, prospective study enrolled patients aged 3–216 months with serum alanine transaminase (ALT) and/or aspartate transaminase (AST) levels >2× the upper limit of normal (ULN) for ≥3 months. Patients with a known history of liver or muscle disease or physical examination findings suggestive of liver disease were excluded. Patients were screened for creatinine phosphokinase (CPK) levels, and molecular genetic tests for DMD/BMD in male patients and enzyme analysis for PD in male and female patients with elevated CPK levels were performed. Genetic analyses confirmed PD. Demographic, clinical, and laboratory characteristics of the patients were analyzed.ResultsOverall, 589 patients [66.8% male, mean age of 63.4 months (standard deviation: 60.5)] were included. In total, 251 patients (188 male and 63 female) had CPK levels above the ULN. Of the patients assessed, 47% (85/182) of male patients were diagnosed with DMD/BMD and 1% (3/228) of male and female patients were diagnosed with PD. The median ALT, AST, and CPK levels were statistically significantly higher, and the questioned neurological symptoms and previously unnoticed examination findings were more common in DMD/BMD patients than those without DMD/BMD or PD (p < 0.001).DiscussionQuestioning neurological symptoms, conducting a complete physical examination, and testing for CPK levels in patients with isolated hypertransaminasemia will prevent costly and time-consuming investigations for liver diseases and will lead to the diagnosis of occult neuromuscular diseases. Trial RegistrationClinicaltrials.gov NCT04120168

Seismic upgrade of a reinforced concrete building

This paper discusses results from an analytical investigation conducted to study the ductility demands imposed on reinforced concrete beams and columns of three-bay six-story reinforced concrete frames subjected to earthquake type loads. The ultimate goal of this study is to investigate and compare the behavior of Frame-NS, the ordinary moment resisting frame, and Frame-S, the special moment resisting frame designed to comply with the seismic design requirements of ACI 318-99[1], UBC-97[2], CAN A23.3-94[3] and NBC-95[4]. Determination of the critical locations in these frames and devising upgrade schemes that are consistent with the ductility demands on these locations constituted significant milestones in the seismic retrofit design. Although Frame-S displayed a higher level of ductility in comparison to Frame-NS, the pushover analyses results indicated that the most critical column hinges of Frame-S exploited their deformation capacities just prior to collapse. The most critical beam hinge, on the other hand, exploited 37% of its deformation capacity. More significantly, only 21% of the beam deformation capacities were exploited in the Frame-NS just prior to its collapse. The potential plastic hinge regions of the columns of Frame-S and Frame-NS were then wrapped using carbon fiber reinforced polymer fabrics impregnated with epoxy. Due to better confinement of the plastic hinge regions of the columns, their sectional deformation capacities increased considerably. Hence, the available deformation and energy absorption capacities of the beam hinges were mobilized to considerably higher levels (up to 48% in Frame-NS and up to 75% in Frame-S)

Closure to "Punching shear strengthening of reinforced concrete flat plates using carbon fiber reinforced polymers" by Baris Binici and Oguzhan Bayrak

This research presents a strengthening technique for increasing punching shear resistance in reinforced concrete flat plates using carbon fiber reinforced polymers (CFRPs). This strengthening method employs CFRP strips in the vertical direction as shear reinforcement around the concentrated load area in a specified pattern. Experimental load deflection curves, strain measurements, and failure modes are reported for four strengthened specimens and two reference specimens tested for the research reported here. The results show that, by using a sufficient amount of CFRP strips in an efficient configuration, the failure surface can be shifted away from the column. The load carrying capacities of the strengthened reinforced concrete slabs are increased with increasing amount of vertical CFRP reinforcement used in a wider area. Punching shear strengths of test specimens are augmented up to 51% relative to the control specimens. The pre- and postpunching behavior of the specimen with the highest increase in load carrying capacity is better than that of the reference specimen designed according to the current requirements of ACI 318-02. ACI 318-02 and CEB-FIP Model Code 90 requirements for punching shear design are critically examined in the light of current experimental findings

Upgrading of slab-column connections using fiber reinforced polymers

The results of an experimental program on upgrading of reinforced concrete slab-column connections subjected to monotonic shear and unbalanced moment transfer are presented in this study. Externally installed carbon fiber reinforced polymer (CFRP) stirrups acting as shear reinforcement around the slab-column connection area were used with two patterns of CFRP arrangements. It was found that the proposed method resulted in punching shear capacity increases up to 60% relative to the specimen without any strengthening. In some cases punching shear failure was eliminated with the use of CFRPs as shear reinforcement. Capacities of test specimens were evaluated using punching shear strength provisions of ACI 318-02 and yield line analyses for the test specimens. On the basis of the results of this study. use of CFRPs as externally installed stirrups was found to be successful in strengthening slab-column connections

Use of fiber-reinforced polymers in slab-column connection upgrades

The results of an experimental program on punching shear-strengthening of reinforced concrete slab-column connections using carbon fiber-reinforced polymers (CFRPs) are presented ill this paper. Externally installed CFRP stirrups serving as shear reinforcement were used as a strengthening technique. The effectiveness of different patterns, detailing, and various amounts of CFRP for strengthening were studied. It was found that the proposed method resulted in punching shear capacity increases up to 60% relative to the specimen without any strengthening. In addition, displacement ductility and postpunching resistance of the strengthened specimens increased, resulting in a more ductile failure mode than that of the control specimen. A design method based oil ACI 318-02 expressions is also presented for this innovative use of CFRP for strengthening slab-column connections

Seismic upgrade of reinforced concrete slab-column connections using carbon fiber-reinforced polymers

The results of an experimental program on seismic upgrade of slab-column connections are presented in this paper Two of the four slab-column specimens designed according to ACI 318-63 code provisions were upgraded by externally installed carbon fiber-reinforced polymer (CFRP) stirrups and the other two, designed and detailed according to the ACI 318-63 and ACI 318-02 codes, respectively, served as control specimens. Specimens were tested under constant gravity shear and lateral displacements were applied in a reversed cyclic manner Punching shear failure occurred for the control specimens at a lateral drift-ratio of approximately 2%. Upgraded specimens had significant flexural yielding and sustained deformations up to a drift ratio of approximately 8% without significant losses of strength. Punching failure was not observed in the upgraded specimens. In the upgraded specimens, displacement ductility increased by a factor of at least 2 and the joint rotation ductility factor increased up to 3.5 times that of the control specimen. The results of the experimental program showed that the proposed upgrade method is successful in increasing deformation capacity and avoiding brittle failures that can occur under high gravity loadings

An asymptotically stable robust controller formulation for a class of MIMO nonlinear systems with uncertain dynamics

In this work, we present a novel continuous robust controller for a class of multi-input/multi-output nonlinear systems that contains unstructured uncertainties in their drift vectors and input matrices. The proposed controller compensates uncertainties in the system dynamics and achieves asymptotic tracking while requiring only the knowledge of the sign of the leading principal minors of the input gain matrix. A Lyapunov-based argument backed up with an integral inequality is applied to prove the asymptotic stability of the closed-loop system. Simulation results are presented to illustrate the viability of the proposed method.Scientific and Technological Research Council of Turkey (113E147