4,667 research outputs found
Response and optimization of an isolation system with relaxation type damping
Response and optimization of isolation system with relaxation type dampin
Study of active vibration isolation systems for severe ground transportation environments
Active vibration isolation systems for severe ground transportation loading environment
Effect of vertical active vibration isolation on tracking performance and on ride qualities
An investigation to determine the effect on pilot performance and comfort of an active vibration isolation system for a commercial transport pilot seat is reported. The test setup consisted of: a hydraulic shaker which produced random vertical vibration inputs; the active vibration isolation system; the pilot seat; the pilot control wheel and column; the side-arm controller; and a two-axis compensatory tracking task. The effects of various degrees of pilot isolation on short-term (two-minute) tracking performance and comfort were determined
More favorable metabolic impact of three-times-weekly versus daily growth hormone (GH) treatment in na\uefve GH-deficient children
OBJECTIVE: Growth hormone treatment (GHT) is commonly administered daily, although pulsatile GH secretion is unlikely to be achieved. The auxological effect of a three-injections-per-week (TIW) regimen is controversial, while the metabolic effects have been never evaluated in children. The objective was to evaluate whether two different regimens of weekly injections could lead to similar auxological and metabolic effects in children with GH deficiency (GHD).
DESIGN: 32 GHD children (25 males, mean age 10.5 \ub1 2.2 yr) were randomly assigned to receive daily (group A, No 16) or TIW (group B, No 16) GHT for 12 months.
METHODS: Auxological parameters, insulin-like growth factor-I (IGF-I), glucose and insulin during OGTT, glycosylated hemoglobin (HbA1c), lipid profile, the oral disposition index (DIo), the homeostasis model assessment estimate of insulin resistance (Homa-IR) and the insulin sensitivity index (ISI).
RESULTS: After 12 months, both groups showed a significant and comparable improvement in height (p<0.001) and IGF-I (p<0.001). As regards the metabolic parameters, in both groups we found a significant increase in fasting insulin (p<0.001 and p=0.026) and Homa-IR (p<0.001 and p=0.019). A significant increase in fasting glucose (p=0.001) and a decrease in ISI (p<0.001) and DIo (p=0.002) were only found in group A.
CONCLUSIONS: The TIW regimen is effective and comparable with the daily regimen in improving auxological parameters and has a more favorable metabolic impact in GHD children (www.ClinicalTrials.gov. NCT03033121)
Chirality effects on the IRMPD spectra of basket resorcinarene/nucleoside complexes
The IRMPD spectra of the
ESI-formed proton-bound complexes
of the R,R,R,R- and S,S,S,S-enantiomers
of a bis(diamido)-bridged basket
resorcin[4]arene (R and S) with cytosine
(1), cytidine (2), and cytarabine
(3) were measured in the region 2800–
3600 cm1. Comparison of the IRMPD
spectra with the corresponding
ONIOM (B3LYP/6-31(d):UFF)-calculated
absorption frequencies allowed
the assessment of the vibrational
modes that are responsible for the observed
spectroscopic features. All of
the complexes investigated, apart from
[R·H·3]+, showed similar IRMPD spectra,
which points to similar structural
and conformational landscapes. Their
IRMPD spectra agree with the formation
of several isomeric structures in
the ESI source, wherein the N(3)-protonated
guest establishes noncovalent
interactions with the host amidocarbonyl
groups that are either oriented
inside the host cavity or outside it between
one of the bridged side-chains
and the upper aromatic nucleus. The
IRMPD spectrum of the [R·H·3]+ complex
was clearly different from the
others. This difference is attributed to the effect of intramolecular hydrogen bonding interactions between the
C(2’)-OH group and the aglycone oxygen atom of the nucleosidic guest upon repulsive interactions between
the same oxygen atom and the aromatic rings of the host
Costimulatory Molecules and Immune Checkpoints Are Differentially Expressed on Different Subsets of Dendritic Cells
Dendritic cells (DCs) play a crucial role in initiating and shaping immune responses. The effects of DCs on adaptive immune responses depend partly on functional specialization of distinct DC subsets, and partly on the activation state of DCs, which is largely dictated by environmental signals. Fully activated immunostimulatory DCs express high levels of costimulatory molecules, produce pro-inflammatory cytokines, and stimulate T cell proliferation, whereas tolerogenic DCs express low levels of costimulatory molecules, produce immunomodulatory cytokines and impair T cell proliferation. Relevant to the increasing use of immune checkpoint blockade in cancer treatment, signals generated from inhibitory checkpoint molecules on DC surface may also contribute to the inhibitory properties of tolerogenic DCs. Yet, our knowledge on the expression of inhibitory molecules on human DC subsets is fragmentary. Therefore, in this study, we investigated the expression of three immune checkpoints on peripheral blood DC subsets, in basal conditions and upon exposure to pro-inflammatory and anti-inflammatory stimuli, by using a flow cytometric panel that allows a direct comparison of the activatory/inhibitory phenotype of DC-lineage and inflammatory DC subsets. We demonstrated that functionally distinct DC subsets are characterized by differential expression of activatory and inhibitory molecules, and that cDC1s in particular are endowed with a unique immune checkpoint repertoire characterized by high TIM-3 expression, scarce PD-L1 expression and lack of ILT2. Notably, this unique cDC1 repertoire was subverted in a group of patients with myelodysplastic syndromes included in the study. Applied to the characterization of DCs in the tumor microenvironment, this panel has the potential to provide valuable information to be used for investigating the role of DC subsets in cancer, guiding DC-targeting treatments, and possibly identifying predictive biomarkers for clinical response to cancer immunotherapy
Altered Metabolic Profile in Congenital Lung Lesions Revealed by1H Nuclear Magnetic Resonance Spectroscopy
Congenital lung lesions are highly complex with respect to pathogenesis and treatment. Large-scale analytical methods, like metabolomics, are now available to identify biomarkers of pathological phenotypes and to facilitate clinical management. Nuclear magnetic resonance (NMR) is a unique tool for translational research, as in vitro results can be potentially translated into in vivo magnetic resonance protocols. Three surgical biopsies, from congenital lung malformations, were analyzed in comparison with one control sample. Extracted hydrophilic metabolites were submitted to high resolution 1H NMR spectroscopy and the relative concentration of 12 metabolites was estimated. In addition, two-dimensional NMR measurements were performed to complement the results obtained from standard monodimensional experiments. This is one of the first reports of in vitro metabolic profiling of congenital lung malformation. Preliminary data on a small set of samples highlights some altered metabolic ratios, dealing with the glucose conversion to lactate, to the relative concentration of phosphatidylcholine precursors, and to the presence of myoinositol. Interestingly some relations between congenital lung lesions and cancer metabolic alterations are found
Accuracy of a Wrist-Worn Heart Rate Sensing Device during Elective Pediatric Surgical Procedures
The reliability of wearable photoplethysmography (PPG) sensors to measure heart rate (HR) in hospitalized patients has only been demonstrated in adults. We evaluated the accuracy of HR monitoring with a personal fitness tracker (PFT) in children undergoing surgery. HR monitoring was performed using a wrist-worn PFT (Fitbit Charge HR) in 30 children (8.21 \ub1 3.09 years) undergoing laparoscopy (n = 8) or open surgery (n = 22). HR values were analyzed preoperatively and during surgery. The accuracy of HR recordings was compared with measurements recorded during continuous electrocardiographic (cECG) monitoring; HRs derived from continuous monitoring with pulse oximetry (SpO2R) were used as a positive control. PFT-derived HR values were in agreement with those recorded during cECG (r = 0.99) and SpO2R (r = 0.99) monitoring. PFT performance remained high in children < 8 years (r = 0.99), with a weight < 30 kg (r = 0.99) and when the HR was < 70 beats per minute (bpm) (r = 0.91) or > 140 bpm (r = 0.99). PFT accuracy was similar during laparoscopy and open surgery, as well as preoperatively and during the intervention (r > 0.9). PFT-derived HR showed excellent accuracy compared with HRs measured by cECG and SpO2R during pediatric surgical procedures. Further clinical evaluation is needed to define whether PFTs can be used in different health care settings
The role of fetal, infant, and childhood nutrition in the timing of sexual maturation
Puberty is a crucial developmental stage in the life span, necessary to achieve reproductive and somatic maturity. Timing of puberty is modulated by and responds to central neurotransmitters, hormones, and environmental factors leading to hypothalamic-pituitary-gonadal axis maturation. The connection between hormones and nutrition during critical periods of growth, like fetal life or infancy, is fundamental for metabolic adaptation response and pubertal development control and prediction. Since birth weight is an important indicator of growth estimation during fetal life, restricted prenatal growth, such as intrauterine growth restriction (IUGR) and small for gestational age (SGA), may impact endocrine system, affecting pubertal development. Successively, lactation along with early life optimal nutrition during infancy and childhood may be important in order to set up timing of sexual maturation and provide successful reproduction at a later time. Sexual maturation and healthy growth are also influenced by nutrition requirements and diet composition. Early nutritional surveillance and monitoring of pubertal development is recommended in all children, particularly in those at risk, such as the ones born SGA and/or IUGR, as well as in the case of sudden weight gain during infancy. Adequate macro and micronutrient intake is essential for healthy growth and sexual maturity
Gender-based differences in the clustering of metabolic syndrome factors in children and adolescents
We depicted gender-differences in metabolic syndrome (MS) clustering before and after puberty in pediatrics, in order to develop gender specific preventive strategies for childhood obesity. We considered 1079 children and adolescents (529 females and 550 males; mean age 11.5 \ub1 2.8 year). According to body mass index (BMI) percentiles the subjects were classified as normal weight BMI <75th, overweight BMI 75-95th and with obesity BMI >95th. MS was diagnosed when three of the following criteria for age and sex percentiles were met: BMI >95th, triglycerides (TGs) level >95th, high-density lipoprotein-cholesterol (HDL-c) level <5th, blood pressure (blood pressure) >95th percentile, fasting blood glucose (FBG) >100 mg/dL and/or homeostatic model assessment-insulin resistance (HOMA-IR) >97.5th percentile. The prevalence of dismetabolic factors was similar in both genders, except for pathological BP, which was higher in males (p = 0.02). MS was detected only in patients with obesity, with a higher prevalence in pubertal than late/post-pubertal subjects (p < 0.001), without any significant difference between gender. In pre-puberty, the most common MS combination was obesity (HBMI) + hypertension (HBP) + hyperglycemia/insulin resistance (HGLY/IR) followed by HBMI + low HDL-levels (LHDL) + HGLY/IR versus HBMI + HBP + HGLY/IR followed by HBMI + HBP + LHDL, respectively, in females and males. In the early and late/post-pubertal periods, the most prevalent combination remained similar to pre-puberty, additionally in both sexes other combinations, such as HBMI + HTG + HBP + HGLY/IR, HBMI + HBP + LHDL + HGLY/IR, HBMI + HTG + LHDL + HGLY/IR and HBMI + HTG + LHDL + HBP + HGLY/IR were also detected, differently distributed in males and females. We confirm that MS is an important consequence related to obesity, particularly in the post-puberty stage. Some gender-based differences should be considered early in order to identify specific preventive and treatment strategies
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