Pengaruh Kuat Arus Dan Waktu Pengelasan Pada Proses Las Titik (Spot Welding) Terhadap Kekuatan Tarik Dan Mikrostuktur Hasil Las Dari Baja Fasa Ganda (Feritte-Martensite)

This research was conducted to investigate the appropiate spot welding variable to get the maximum tensile strength. The highest of tensile strength referred as good quality of weldment.The plate was made from low carbon steel with phase ferrite and martensite. The current of welding used 0.9 kA, 1.6 kA, dan 1.85 kA with welding time were 0.25, 0.5 , 0.75 and 1 second. Mechanical properties testing done involved tensile strength to know shear strength of weld joint. Microstructure test used optical microscope.The results show that spot welding with thecurrent of 1.85kA and welding time of 1 second has the highest tensile strength (about 237.04N/mm2). On the other hand, the lowest tensile strength (150 N/mm2) was produced by combination of 0.9 kA and 0.25 second welding time. It was caused by recrystallization phasedeformation on steel

Functional polymorphisms in the LDLR and pharmacokinetics of Factor VIII concentrates

Background: Optimization of factor VIII (FVIII) infusion in hemophilia A would benefit from identification of FVIII pharmacokinetics (PK) determinants. The low‐density lipoprotein receptor (LDLR) contains an FVIII‐binding site and might influence FVIII clearance. Consistently, LDLR polymorphisms have been associated with FVIII levels. Objective: To investigate the relationships between individual FVIII PK and functional LDLR polymorphisms. Patients/Methods: Thirty‐three hemophilia A patients (FVIII coagulant activity [FVIII:C] ≤2 IU/dL) without inhibitors underwent 85 FVIII single‐dose (21.4‐51.8 IU/ kg) PKs with different FVIII concentrates. Twenty patients underwent repeated PKs (2‐6). FVIII:C measured up to 72 hours was analyzed by two‐compartment model. Parameters were evaluated in relation to F8 mutations, ABO blood‐group and LDLR genotypes. Results: F8 mutation types were not associated with PK parameters. ABO and LDLR c.1773C/T polymorphism were associated with Alpha, Alpha HL, CLD2, K1‐2, and K2‐1 parameters, suggesting an influence on the FVIII initial distribution phase. Regression analysis showed an independent association of both ABO and LDLR c.1773C/T with PK parameters (Alpha, β‐coefficient −0.311 vs 0.348; CLD2, β‐coefficient −0.335 vs 0.318), giving rise to an additive effect in subjects stratified by combined phenotypes. Differently, the LDLR c.81C/T was associated with FVIII clearance and volume of distribution at steady state, which could be related to distinct effects of polymorphisms, potentially linked to LDLR intracellular distribution and FVIII binding behavior. Conclusions: With the limitation of different FVIII concentrates and low number of patients, our data show plausible associations of LDLR polymorphisms with FVIII PK parameters, thus supporting their investigation as candidate functional determinants of FVIII PK

The Asialoglycoprotein Receptor Minor Subunit Gene Contributes to Pharmacokinetics of Factor VIII Concentrates in Hemophilia A

Background The asialoglycoprotein receptor (ASGPR) binds with high affinity factor VIII (FVIII) through its N -linked oligosaccharides. However, its contribution to the wide inter-individual variation of infused FVIII pharmacokinetics (PK) in hemophilia A (HA) is unknown.Objective To investigate the variability in FVIII PK outcomes in relation to genetic variation in the ASGR2, encoding the ASGPR2 subunit.Methods Thirty-two HA patients with FVIII:C <= 2IU/dL underwent 66 single-dose FVIII PK studies. PK parameters were evaluated in relation to ASGR2 5 untranslated region (5UTR) polymorphisms, which were investigated by recombinant and white blood cell reverse transcription-polymerase chain reaction approaches.Results The 5 ' UTR polymorphisms determine a frequent and conserved haplotype (HT1) in a regulatory region. The HT1 homozygotes may differ in the amounts of alternatively spliced mRNA transcripts and thus ASGPR2 isoforms. Compared with the other ASGR2 genotypes, the c.-95TT homozygotes ( n =9), showed threefold longer Alpha HL (3.60hours, 95% confidence interval: 1.44-5.76, p =0.006), and the c.-95TC heterozygotes ( n =17) showed 25% shorter mean residence time (MRT; 18.5hours, 15.0-22.0, p =0.038) and 32% shorter Beta HL (13.5hours, 10.9-16.0, p =0.016). These differences were confirmed in patients ( n =27) undergoing PK studies ( n =54) with full-length FVIII only. In different linear regression models, the contribution of the ASGR2 genotypes remained significant after adjustment by ABO genotypes and von Willebrand factor (VWF) antigen levels, and explained 14% (MRT), 15 to 18% (Beta HL), and 22% (Alpha HL) of parameter variability.Conclusions Infused FVIII distribution was modulated by frequent ASGR2 genotypes, independently from and together with ABO and VWF antigen levels, which has potential implications for genetically tailored substitutive treatment in HA

Population diversity of the genetically determined TTR expression in human tissues and its implications in TTR amyloidosis

BACKGROUND: Transthyretin (TTR) amyloidosis is a hereditary disease with a complex genotype-phenotype correlation. We conducted a literature survey to define the clinical landscape of TTR amyloidosis across populations worldwide. Then, we investigated whether the genetically determined TTR expression differs among human populations, contributing to the differences observed in patients. Polygenic scores for genetically determined TTR expression in 14 clinically relevant tissues were constructed using data from the GTEx (Genotype-Tissue Expression) project and tested in the samples from the 1,000 Genomes Project.RESULTS: We observed differences among the ancestral groups and, to a lesser extent, among the investigated populations within the ancestry groups. Scandinavian populations differed in their genetically determined TTR expression of skeletal muscle tissue with respect to Southern Europeans (p\u2009=\u20096.79*10-6). This is in line with epidemiological data related to Swedish and Portuguese TTR Val30Met endemic areas. Familial amyloidotic cardiomyopathy (TTR deposits occur primarily in heart tissues) presents clinical variability among human populations, a finding that agrees with the among-ancestry diversity of genetically determined TTR expression in heart tissues (i.e., Atrial Appendage p\u2009=\u20094.55*10-28; Left Ventricle p\u2009=\u20096.54*10-35).CONCLUSIONS: Genetically determined TTR expression varied across human populations. This might contribute to the genotype-phenotype correlation of TTR amyloidosis

A Systematic Assessment of Accuracy in Detecting Somatic Mosaic Variants by Deep Amplicon Sequencing: Application to <i>NF2</i> Gene

<div><p>The accurate detection of low-allelic variants is still challenging, particularly for the identification of somatic mosaicism, where matched control sample is not available. High throughput sequencing, by the simultaneous and independent analysis of thousands of different DNA fragments, might overcome many of the limits of traditional methods, greatly increasing the sensitivity. However, it is necessary to take into account the high number of false positives that may arise due to the lack of matched control samples. Here, we applied deep amplicon sequencing to the analysis of samples with known genotype and variant allele fraction (VAF) followed by a tailored statistical analysis. This method allowed to define a minimum value of VAF for detecting mosaic variants with high accuracy. Then, we exploited the estimated VAF to select candidate alterations in <i>NF2</i> gene in 34 samples with unknown genotype (30 blood and 4 tumor DNAs), demonstrating the suitability of our method. The strategy we propose optimizes the use of deep amplicon sequencing for the identification of low abundance variants. Moreover, our method can be applied to different high throughput sequencing approaches to estimate the background noise and define the accuracy of the experimental design.</p></div

Phenotypic profile of Ile68Leu transthyretin amyloidosis: an underdiagnosed cause of heart failure

Aims: Cardiac amyloidosis remains a great challenge for the cardiologist. One of the three main aetiological forms, transthyretin-related hereditary amyloidosis (ATTRm), can present with several phenotypes, depending mainly on the specific mutation. We aimed to characterize the phenotype of patients with ATTRm due to Ile68Leu mutation, comparing them to patients with wild-type transthyretin amyloidosis (ATTRwt). Methods and results: Data of 67 Ile68Leu ATTRm patients from two Italian referral centres (Bologna and Florence) were retrospectively analysed and compared to those of 82 ATTRwt patients. Fifty-five unaffected mutation carriers were also analysed. Cumulative disease onset was 50% at age 71. A total of 56/67 (84%) patients had a predominantly cardiac phenotype at presentation with concentric increase in left ventricular wall thickness [median 17 mm], and normal or near normal left ventricular ejection fraction (79% of patients). Low QRS voltages were present only in 29% of patients but voltage/mass ratio was low (0.5). Carpal tunnel syndrome was noted in 43%. The overall phenotypic profile was similar to ATTRwt but Ile68Leu ATTRm patients typically presented younger (median 71 vs. 78 years) and were more likely to have (mild) symptomatic neurological involvement (19% vs. 2%). Male prevalence was 44% in unaffected mutation carriers and 78% in affected patients. Age-adjusted survival was comparable between groups. Conclusions: Ile68Leu ATTRm is a cause of familial amyloidotic cardiomyopathy endemic in central-northern Italy and presents as hypertrophic/restrictive cardiomyopathy quite similar to ATTRwt. Male preponderance is present in affected patients but not in unaffected mutation carriers. Age-adjusted survival is similar to ATTRwt

Results of ROC curve analysis on calibration samples.

<p>^a TPR and FPR are calculated from ROC curves at the best VAF cut-off. This data do not contain recurrent events.</p><p>^b The number of FPs at each cut-off value was estimated by the product of FPR and the number of detected variants per sample</p><p>Results of ROC curve analysis on calibration samples.</p

Features of false positives events detected in calibration samples.

<p>(a) Boxplot of VAFs of events detected by MuTect (SNVs) and IndelGenotyperV2 (InDels). n is the total number of detected events, n* is the mean number of events (per sample) with the corresponding standard deviation. (b) Histogram of events recurrence among calibration samples (n = 30) for SNVs (black) and InDels (grey). Corresponding cumulative percentages are reported in dashed black (SNVs) and grey (InDels) lines.</p