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Introduction and importanceAlthough the common complications of Meckel's diverticulum (MD) are well known, that these congenital intestinal outpouchings may become involved as the content of abdominal hernia sacs is not well appreciated. MD is the most prevalent congenital abnormality of the gastrointestinal tract, but involvement in a hernia, known as Littre's hernia (LH), accounts for less than 1 % of MD cases. Incarcerated LH has been reported sporadically in the literature, with MD found in the sacs of paraumbilical, femoral, inguinal, and incisional hernias.Presentation of caseWe report a LH in a 3-year-old male child who was scheduled for elective herniotomy for a reducible left inguinal hernia. Intraoperatively we found the hernia sac contained a necrotic and perforated MD with viable associated bowel loop. The patient was successfully managed by diverticulectomy and primary repair through a trans-inguinal incision and herniotomy was performed.Clinical discussionLH is a rare presentation of MD, and preoperative diagnosis of LH is challenging. Even in the case of a strangulated MD, a patient may not present with the typical signs and symptoms associated with compromised viscous. Once identified, repair of Littre hernia consists of resection of the diverticulum, or segmental bowel resection if necessary, and herniotomy.ConclusionThe finding of a perforated MD during elective hernia repair emphasizes the importance of awareness of unusual variants of inguinal hernia, and the necessity of identifying a MD given the risk of sequelae in the case of necrosis or perforation, if not repaired.

Heart failure (HF) is characterized by global alterations in myocardial DNA methylation, yet little is known about the epigenetic regulation of the noncoding genome and potential reversibility of DNA methylation with left ventricular assist device (LVAD) therapy. Genome-wide mapping of myocardial DNA methylation in 36 patients with HF at LVAD implantation, 8 patients at LVAD explantation, and 7 nonfailing (NF) donors using a high-density bead array platform identified 2,079 differentially methylated positions (DMPs) in ischemic cardiomyopathy (ICM) and 261 DMPs in nonischemic cardiomyopathy (NICM). LVAD support resulted in normalization of 3.2% of HF-associated DMPs. Methylation-expression correlation analysis yielded several protein-coding genes that are hypomethylated and upregulated (HTRA1, FBXO16, EFCAB13, and AKAP13) or hypermethylated and downregulated (TBX3) in HF. A potentially novel cardiac-specific super-enhancer long noncoding RNA (lncRNA) (LINC00881) is hypermethylated and downregulated in human HF. LINC00881 is an upstream regulator of sarcomere and calcium channel gene expression including MYH6, CACNA1C, and RYR2. LINC00881 knockdown reduces peak calcium amplitude in the beating human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). These data suggest that HF-associated changes in myocardial DNA methylation within coding and noncoding genomes are minimally reversible with mechanical unloading. Epigenetic reprogramming strategies may be necessary to achieve sustained clinical recovery from heart failure.

Heart failure (HF) is characterized by global alterations in myocardial DNA methylation, yet little is known about the epigenetic regulation of the noncoding genome and potential reversibility of DNA methylation with left ventricular assist device (LVAD) therapy. Genome-wide mapping of myocardial DNA methylation in 36 patients with HF at LVAD implantation, 8 patients at LVAD explantation, and 7 nonfailing (NF) donors using a high-density bead array platform identified 2,079 differentially methylated positions (DMPs) in ischemic cardiomyopathy (ICM) and 261 DMPs in nonischemic cardiomyopathy (NICM). LVAD support resulted in normalization of 3.2% of HF-associated DMPs. Methylation-expression correlation analysis yielded several protein-coding genes that are hypomethylated and upregulated (HTRA1, FBXO16, EFCAB13, and AKAP13) or hypermethylated and downregulated (TBX3) in HF. A potentially novel cardiac-specific super-enhancer long noncoding RNA (lncRNA) (LINC00881) is hypermethylated and downregulated in human HF. LINC00881 is an upstream regulator of sarcomere and calcium channel gene expression including MYH6, CACNA1C, and RYR2. LINC00881 knockdown reduces peak calcium amplitude in the beating human induced pluripotent stem cell–derived cardiomyocytes (hiPSC-CMs). These data suggest that HF-associated changes in myocardial DNA methylation within coding and noncoding genomes are minimally reversible with mechanical unloading. Epigenetic reprogramming strategies may be necessary to achieve sustained clinical recovery from heart failure.

The umbilicus is a site of numerous embryopathies involving vessels, urachus, mid gut herniation, anterior abdominal wall defects and congenital cysts. Owing to lack of awareness, umbilical cord hernia (HUC) is often misdiagnosed and underreported, with limited data in the literature. We report an isolated case of congenital HUC and perinatal transection of the sigmoid colon during cord ligature by a midwife in a local health center.A six-day old female neonate presented with discharge of fecal matter through the umbilicus. The clamped cord, became swollen and auto-amputated on day of life three, after which fecal discharge was from the stump was noted. On examination a visible bowel loop containing stool was seen in the umbilical cord. We proceeded with surgical intervention via a small umbilical incision, with findings of transection of the sigmoid colon, no peritoneal contamination, and primary anastomosis was performed. There was event free recovery postoperatively.HUC is poorly understood and often misdiagnosed as omphalocele minor. One should be cognizant of HUC when noting swelling at the base of the cord so as to avoid any inadvertent iatrogenic enterotomy by close umbilical clamping.

Despite enhancements in the development of robotic systems, the energy economy of today's robots lags far behind that of biological systems. This is in particular critical for untethered legged robot locomotion. To elucidate the current stage of energy efficiency in legged robotic systems, this paper provides an overview on recent advancements in development of such platforms. The covered different perspectives include actuation, leg structure, control and locomotion principles. We review various robotic actuators exploiting compliance in series and in parallel with the drive-train to permit energy recycling during locomotion. We discuss the importance of limb segmentation under efficiency aspects and with respect to design, dynamics analysis and control of legged robots. This paper also reviews a number of control approaches allowing for energy efficient locomotion of robots by exploiting the natural dynamics of the system, and by utilizing optimal control approaches targeting locomotion expenditure. To this end, a set of locomotion principles elaborating on models for energetics, dynamics, and of the systems is studied.

Despite enhancements in the development of robotic systems, the energy economy of today's robots lags far behind that of biological systems. This is in particular critical for untethered legged robot locomotion. To elucidate the current stage of energy efficiency in legged robotic systems, this paper provides an overview on recent advancements in development of such platforms. The covered different perspectives include actuation, leg structure, control and locomotion principles. We review various robotic actuators exploiting compliance in series and in parallel with the drive-train to permit energy recycling during locomotion. We discuss the importance of limb segmentation under efficiency aspects and with respect to design, dynamics analysis and control of legged robots. This paper also reviews a number of control approaches allowing for energy efficient locomotion of robots by exploiting the natural dynamics of the system, and by utilizing optimal control approaches targeting locomotion expenditure. To this end, a set of locomotion principles elaborating on models for energetics, dynamics, and of the systems is studied.

The current state-of-the-art of variable stiffness actuators consists mostly of different concepts for single-degree of freedom joints. However, in bio-inspired robotic applications, multiple degrees of freedom variable stiffness actuators are often desired. Currently, this is usually achieved by cascading single-degree of freedom actuators. The innovation presented in this work is a two-degree of freedom variable stiffness actuator using the mechanically adjustable and controllable equilibrium position actuator (MACCEPA) concept. The presented actuator is not a cascade of two single-degree of freedom actuators, but centralizes the two degrees of freedom in one single joint. Equilibrium position and stiffness of the actuator are, furthermore, independently controllable in both degrees of freedom. The design and experimental validation of the actuator are discussed in this work. The independence of adjusting the equilibrium position and stiffness of the actuator are experimentally validated. The results show that the measured characteristics of the actuator sufficiently match the theoretically calculated ones. Future work includes implementing the presented two-degree of freedom actuator in an application, like a bipedal robot or a robotic arm.