Total marrow irradiation for second allogeneic hematopoietic stem cell transplantation in patients with advanced acute leukemia

BACKGROUND

Second allogeneic hematopoietic stem cell transplantation (HSCT) is a treatment option for patients with acute leukemia relapsing after a first HSCT. While a myeloablative (MA) conditioning regimen before the first HSCT is considered better than reduced intensity (RIC) in terms of disease control in acute leukemia patients, the optimal conditioning regimen for the second allogeneic HSCT remains controversial. The most important prognostic factors are the remission disease phase at the time of the second HSCT and more than 12 months from the first to the second HSCT. Total Marrow Irradiation (TMI) is an advanced high-precision radiation treatment that delivers therapeutic doses over extensively selected targets while substantially reducing radiation to vital organs compared to conventional Total Body Irradiation (TBI). Herein we report the results of a retrospective analysis on second allogeneic transplantation treated with TMI as a myeloablative conditioning regimen, intending to limit toxicity.

OBJECTIVE

We investigated the efficacy of a high dose per fraction TMI in combination with thiotepa, fludarabine and melphalan in 13 consecutive patients with acute leukemia relapsed after a first allogeneic HSCT treated between March 2018 and November 2021.

STUDY DESIGN

Donor type was haploidentical (HAPLO, n=10), unrelated (UD n=2), and HLA-identical sibling (SIB, n=1). The conditioning regimen consisted of TMI 8 Gy in 5 patients on day -8 -7 or TMI 12 Gy in 8 patients on day -9 -8 -7, plus Thiotepa 5 mg/Kg on day -6, Fludarabine 50 mg/mq on day -5 -4 -3, Melphalan 140 mg/mq on day -2. TMI was delivered in a hypofractionated daily single dose of 4 Gy for three consecutive fractions. The median age was 45 years (range, 19-70 years); 7 patients were in remission, and 6 had active disease at the time of the second allogeneic HSCT.

RESULTS

The median time to neutrophil counts of > 0.5×10e9/L was 16 days (range 13-22), and platelet counts of > 20×10e9/L were 20 days (range 14-34), respectively. All patients showed a complete donor chimerism on day 30 after the transplant. The cumulative incidence of grade I II acute GvHD (aGvHD) was 43%, and chronic GvHD (cGVHD) was 30%. The median follow-up was 1121 days (range 200-1540). Day +30 and +100 transplant-related mortality (TRM) was 0. Overall cumulative incidence of TRM, relapse rate, and disease free-survival (DFS) were respectively 27%,7%, and 67%.

CONCLUSIONS

This retrospective study showed the safety and efficacy of a hypofractionated TMI conditioning regimen in patients with acute leukemia receiving second HSCT with encouraging outcomes regarding engraftment, early toxicity, GvHD, and relapse.

Functional Nanomaterial-Modified Anodes in Microbial Fuel Cells: Advances and Perspectives

Microbial fuel cell (MFC) is a promising approach that could utilize microorganisms to oxidize biodegradable pollutants in wastewater and generate electrical power simultaneously. Introducing advanced anode nanomaterials is generally considered as an effective way to enhance MFC performance by increasing bacterial adhesion and facilitating extracellular electron transfer (EET). This review focuses on the key advances of recent anode modification materials, as well as the current understanding of the microbial EET process occurring at the bacteria-electrode interface. Based on the difference in combination mode of the exoelectrogens and nanomaterials, anode surface modification, hybrid biofilm construction and single-bacterial surface modification strategies are elucidated exhaustively. The inherent mechanisms may help to break through the performance output bottleneck of MFCs by rational design of EET-related nanomaterials, and lead to the widespread application of microbial electrochemical systems.

Enhanced transmembrane electron transfer in Shewanella oneidensis MR-1 using gold nanoparticles for high-performance microbial fuel cells

Low efficiency of extracellular electron transfer (EET) is a major bottleneck in developing high-performance microbial fuel cells (MFCs). Herein, we construct Shewanella oneidensis MR-1@Au for the bioanode of MFCs. Through performance recovery experiments of mutants, we proved that abundant Au nanoparticles not only tightly covered the bacteria surface, but were also distributed in the periplasm and cytoplasm, and even embedded in the outer and inner membranes of the cell. These Au nanoparticles could act as electron conduits to enable highly efficient electron transfer between S. oneidensis MR-1 and electrodes. Strikingly, the maximum power density of the S. oneidensis MR-1@Au bioanode reached up to 3749 mW m^-2, which was 17.4 times higher than that with the native bacteria, reaching the highest performance yet reported in MFCs using Au or Au-based nanocomposites as the anode. This work elucidates the role of Au nanoparticles in promoting transmembrane and extracellular electron transfer from the perspective of molecular biology and electrochemistry, while alleviating bottlenecks in MFC performances.

[Effects of unsafe sexual behavior and sexual orientation on previous HIV testing and HIV testing willingness among college students in Harbin]

Objective: To analyze the effects of unsafe sexual behavior and sexual orientation on previous HIV testing and HIV testing willingness among college students in Harbin, to provide a theoretical basis for promoting and promoting HIV testing among them. Methods: A cross-sectional survey design was used to place the automatic vending machine of HIV urine test kit in 9 universities in Harbin from December 2017 to January 2018. The questionnaire star was used to design and recruit college students to carry out an anonymous online survey. The estimated sample size was 6 659. A multivariate logistic regression model was used to analyze the effects of unsafe sexual behavior and sexual orientation on previous HIV testing and HIV testing willingness among college students. WPS 2016 was used to sort out the database, and SPSS 21.0 software was used for statistical analysis. Results: A total of 60 849 valid questionnaires were collected. 19.1% (11 189/58 605) of college students reported having sex. College students who used condoms correctly every time, occasionally or never during sex in the past six months 58.5% (6 206/10 603), 25.2%(2 669/10 603)and 16.3% (1 728/10 603), respectively. Heterosexuality, homosexuality and bisexuality accounted for 94.1% (54 393/57 823), 2.4% (1 369/57 823) and 3.5% (2 061/57 823), respectively. The HIV testing willingness of college students was 73.3% (44 572/60 849). The proportion of previous HIV testing was 10.3% (951/9 241). Results of the multivariate logistic analysis showed that compared with the college students who used condoms correctly whenever they had sex in the past six months, there was no significant difference in the proportion of previous HIV testing among college students who sometimes/occasionally used or never used condoms (OR=0.94,95%CI:0.69-1.29; OR=1.11,95%CI:0.73-1.67), but their willingness to HIV testing was lower (OR=0.79, 95%CI:0.71-0.89; OR=0.48, 95%CI:0.42-0.55); Compared with heterosexual college students, homosexual or bisexual college students have a higher proportion of previous HIV testing (OR=2.62, 95%CI:1.62-4.24; OR=2.04, 95%CI:1.25-3.32), but have lower HIV testing willingness (OR=0.76, 95%CI: 0.62-0.93; OR=0.64, 95%CI: 0.53-0.77). Conclusions: Unsafe sexual behavior existed among college students in Harbin, and college students with weak awareness of HIV prevention also have weak awareness of testing. Behavioral intervention should be strengthened and HIV testing promoted. Compared with heterosexuals, homosexual or bisexual college students had a higher proportion of previous HIV testing, but their willingness to test was lower. The HIV detection mode with better concealment, accuracy, and convenience should be promoted on the college's campus.

Resource requirements for reintroducing elective surgery during the COVID-19 pandemic: modelling study

Background

The COVID-19 response required the cancellation of all but the most urgent surgical procedures. The number of cancelled surgical procedures owing to Covid-19, and the reintroduction of surgical acivirt, was modelled.

Methods

This was a modelling study using Hospital Episode Statistics data (2014–2019). Surgical procedures were grouped into four urgency classes. Expected numbers of surgical procedures performed between 1 March 2020 and 28 February 2021 were modelled. Procedure deficit was estimated using conservative assumptions and the gradual reintroduction of elective surgery from the 1 June 2020. Costs were calculated using NHS reference costs and are reported as millions or billions of euros. Estimates are reported with 95 per cent confidence intervals.

Results

A total of 547 534 (95 per cent c.i. 3 318 195 to 6 250 771) patients with a pooled mean age of 53.5 years were expected to undergo surgery between 1 March 2020 and 28 February 2021. By 31 May 2020, 749 247 (513 564 to 1 077 448) surgical procedures had been cancelled. Assuming that elective surgery is reintroduced gradually, 2 328 193 (1 483 834 – 3 450 043) patients will be awaiting surgery by 28 February 2021. The cost of delayed procedures is €5.3 (3.1 to 8.0) billion. Safe delivery of surgery during the pandemic will require substantial extra resources costing €526.8 (449.3 to 633.9) million.

Conclusion

As a consequence of the Covid-19 pandemic, provision of elective surgery will be delayed and associated with increased healthcare costs.

Non-fatal cardiovascular events preceding sudden cardiac death in patients with an acute myocardial infarction complicated by heart failure: insights from the High-Risk-Myocardial-Infarction database

Background

Sudden cardiac death (SCD) is responsible for 20–40% of mortality following acute myocardial infarction (AMI). The risk of SCD is even higher among patients with AMI complicated by heart failure (HF) (either clinically apparent HF or left ventricular dysfunction). The temporal relationship between an AMI complicated by HF and subsequent SCD and the association of non-fatal cardiovascular (CV) events following AMI with SCD has yet to be described.

Purpose

Among patients with AMI complicated by HF, we evaluated the probability and temporal association of subsequent non-fatal cardiovascular (CV) events (HF hospitalization, recurrent MI, or stroke) and SCD.

Methods

The High-Risk Myocardial Infarction (HRMI) database contains 28,771 patients with signs of HF or reduced LV ejection fraction (<40%) after AMI. Among patients with an AMI complicated by HF, we used adjudicated cause of death from the HRMI Database to identify: 1) the temporal distribution of SCD among patients following an index AMI; 2) the probability of having SCD following a non-fatal CV event following the index AMI.

Results

Median follow-up was 1.9 years. Mean age was 65.0±11.5 years and 70% were male. The incidence of CV death was 7.9 per 100 patient-year [py] and for SCD was 3.1 per 100py (40% of CV deaths). SCD rates were highest in the early period (<90 days) after AMI and decreased over time. Recurrent MI preceded 9.6% of SCD after a median time of 145 days; HF hospitalization preceded 17.0% of SCD after a median 144 days; and stroke preceded 2.7% of SCD after a median of 138 days (vs. non-sudden CV death: MI 46.6% at 1 days, HF hospitalization: 30.9% at 67 days, stroke 12.9% at 9 days). The incidence of SCD preceded by HF hospitalization was significantly higher than SCD without preceding HF hospitalization.

Conclusion

Among patients with AMI complicated by HF, SCD predominantly occurred in the early “high-risk” period after AMI; SCD rates decreased afterwards. Patients with non-fatal HF hospitalizations during follow-up may have a higher subsequent SCD risk. Preventing HF onset after MI may help decreasing SCD.

Proportion of sudden cardiac death

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Lucien Award, McGill University

Having caregiving responsibilities affects management of fragility fractures and bone health

In this secondary analysis of six qualitative studies, we found that approximately one-quarter of individuals with fragility fracture were serving as informal caregivers. The caregiving role appeared to be a cause of the fracture for some and was prioritized over bone health, acting as a barrier to bone health management.

INTRODUCTION

Among fragility fracture patients serving as informal caregivers, our objective was to examine how caregiving responsibilities were associated with, and possibly impacted by, the fracture experience and the resulting management of bone health.

METHODS

We conducted a secondary analysis (amplified analysis) of six qualitative studies to understand caregiver responsibilities and the relationship between these responsibilities and patients' management of the fracture and bone health. The primary studies and the secondary analysis were conducted from a phenomenological approach. Eligible individuals in the primary studies were English-speaking men and women who were 45+ years old recruited from three settings (local, provincial, and national).

RESULTS

Without being prompted to talk about their experience of caregiving, 33 of 145 (23%) individuals reported they were providing care to a family member or friend at the time of their fracture or during recovery post-fracture. The experience of having caregiving responsibilities was related to the fracture and bone health in two ways: (1) the caregiving role appeared to be a cause of the fracture in some participants and (2) caregiving was prioritized over participants' own bone health and was a barrier to bone health management.

CONCLUSION

Fragility fracture is associated with, and potentially leads to an impairment of, an important social role in patients providing physical and emotional support and supervision for dependents as caregivers. Further, an important cause of fragility fracture can occur in the act of caregiving.

Determination of Minerals and Trace Elements in Milk, Milk Products, Infant Formula, and Adult Nutrition: Collaborative Study 2011.14 Method Modification

Official Method SM 2011.14/ISO 15151:2018/IDF 229:2018 uses microwave digestion of samples and inductively coupled plasma–atomic emission spectrometry for determination of nine elements, including Ca, Cu, Fe, K, Mg, Mn, Na, P, and Zn. The method was evaluated in a collaborative study of 25 products, including 13 fortified nutritional products (powders, ready-to-feed liquids, and liquid concentrates), five product placebos, six dairy products (liquids, powders, butter, and processed cheese), and the National Institute for Standards and Technology (NIST) Standard Reference Material (SRM) 1849a, in compliance with AOAC INTERNATIONAL Standard Method Performance Requirement (SMPR®) 2014.004. This study significantly expanded the applicability of Official Method 2011.14 beyond the original scope of chocolate milk powder, dietetic milk powder, infant cereal, peanut butter, and wheat gluten. The study included 14 collaborators from 11 countries, and results were compared to SMPR 2014.004. Accuracy of the method was demonstrated using NIST SRM 1849a, yielding recoveries across all laboratories of 98–101% for the nine elements. Precision for the 13 fortified nutritional product samples was 2.2–3.9% for repeatability (relative SD of repeatability) and 6.0–12.2% for reproducibility (RSDR). Excluding Mn, which was present at a wide range of concentrations, the reproducibility was 6.0–9.5%, meeting the performance requirements of SMPR 2014.004. Placebo samples (not fortified with Cu, Fe, Mn, or Zn) yielded acceptable repeatability of 1.8–2.9% for Ca, K, Mg, Na, and P (minerals) but 5.4–29.4% for the low levels of Cu, Fe, Mn, and Zn (trace elements). Reproducibility for the placebos showed the same pattern, with acceptable reproducibility (5.4–10.3%) for minerals but not for the low levels of the trace elements (13.2–82.8%). In the six dairy product samples, repeatability ranged from 1.6 to 3.6% for the minerals, Zn, and the low range of Mn but from 9.4 to 24.6% for Cu, Fe, and the high range of Mn, where concentrations were low as for the nutritional placebos. Reproducibility in the dairy samples was 5.3–8.8% for the minerals but 11.4–55.0% for the trace elements. The mean concentrations of Cu, Fe, and Zn in the dairy products were similar with those in the placebo products, while Zn was present at levels more similar with the fortified nutritional products. Thus, the method met the SMPR criteria except where the trace minerals were present at very low levels. Based on these results, the AOAC Stakeholder Panel for Infant Formula and Adult Nutritionals recommended Final Action status of the expanded applicability of the method. The method was adopted as Final Action by the AOAC Official Methods Board.

[Sentinel surveillance for viral hepatitis C in China, 2016-2017]

Objective: To understand the prevalence of hepatitis C virus (HCV) infection in 5 populations in China during 2016-2017 and provide evidence for the estimation of prevalence trend of hepatitis C and evaluation on the prevention and control effect. Methods: A total of 87 national sentinel surveillance sites for hepatitis C were set up in 31 provinces (autonomous regions and municipalities) of China to obtain the information about HCV infection prevalence in 5 populations, including volunteer blood donors, people receiving physical examination, patients receiving invasive diagnosis and treatment, patients receiving hemodialysis, and clients visiting family planning outpatient clinics. From April to June, 2016 and 2017, cross-sectional surveys were repeatedly conducted in the 5 populations and blood samples were collected from them for HCV antibody detection. Results: In 2016, 86 sentinel sites completed the surveillance (one sentinel site was not investigated), and 115 841 persons were surveyed. The overall HCV positive rate was 0.38% (442/115 841, 95%CI: 0.23%-0.53%). In 2017, all the 87 sentinel sites completed the surveillance, and 120 486 persons were surveyed. The overall HCV positive rate was 0.37% (449/120 486, 95%CI: 0.23%-0.52%). In 2016 and 2017, the anti-HCV positive rates were 4.46% (223/5 005, 95%CI: 2.18%-6.73%) and 4.39% (216/4 919, 95%CI: 2.29%-6.50%) respectively in hemodialysis patients, 0.85% (44/5 200, 95%CI: 0.27%-1.42%) and 0.70% (36/5 150, 95%CI: 0.15%-1.24%) respectively in patients receiving invasive diagnosis and treatment and remained to be ≤0.25% in volunteer blood donors, people receiving physical examination and clients visiting family planning outpatient clinics. Results for the comparison of the anti-HCV positive rates in the 5 populations indicated that the differences were significant (F=23.091, P<0.001 in 2016 and F=20.181, P<0.001 in 2017). Conclusions: Data from the sentinel surveillance of HCV infection on prevalence in China showed that the anti-HCV positive rates varied in the 5 populations during 2016-2017. The anti-HCV positive rate appeared the highest in the hemodialysis patients, followed by that in the patients receiving invasive diagnosis and treatment, and the prevalence of HCV infection in other 3 populations were at low levels.

Retracted Article: High-throughput metabolomics identifies serum metabolic signatures in acute kidney injury using LC-MS combined with pattern recognition approach

Metabolomics, as a promising and powerful approach, refers to comprehensive assessment and identification of small molecule endogenous metabolites in a biological system which is capable of further understanding the mechanisms of diseases for early diagnosis, effective treatment and prognosis. Acute kidney injury (AKI) induced by contrast is a serious complication in patients undergoing administration of iodinated contrast media. It is becoming a major health concern in clinic, however, the molecular mechanisms of contrast-induced acute kidney injury (CI-AKI) have not been well characterized. In this study, we used serum metabolomics based on liquid chromatography-mass spectrometry (LC-MS) combined with pattern recognition to explore and characterize potential metabolites and metabolic pathway in an experimental model for CI-AKI. Seventeen differentiating metabolites in the serum were identified involving the pivotal metabolic pathways related to tryptophan metabolism, glycerophospholipid metabolism, steroid hormone biosynthesis, pyrimidine metabolism, sphingolipid metabolism, aminoacyl-tRNA biosynthesis. Our study provides novel insight into pathophysiologic mechanisms of AKI by changing biomarkers and pathways.

[Risk factors related to HIV new infections among men who have sex with men in a cohort study]

Objectives: To analyze and understand the risk factors related to HIV new infections among men who have sex with men (MSM). Methods: A longitudinal observational study among MSM was conducted to collect information on HIV related behaviors and sero-conversion. Univariate and multivariate generalized estimating equations (GEE) were used to discuss the risk factors for HIV new infection. Results: A total number of 4 305 MSM were followed during 2013-2015. Among those self-reported MSM who are seeking partners on the Interner tended to have higher proportion on receptive anal intercourse and consistent condom use during anal intercourse than the subgroups seeking their partners in gay bars or bathrooms. HIV incidence among followed MSM during the study period appeared as 4.3/100 person years, with adjusted RR (aRR) of HIV infection for receptive anal intercourse as group 2.20 (95% CI: 1.49-3.24) times than that of insertion anal intercourse group. Those who used rush-poppers (aRR=1.55, 95% CI: 1.10-2.17), unprotected anal intercourse (aRR=2.24, 95%CI: 1.62-3.08), and those with syphilis infection (aRR=2.95, 95%CI: 2.00-4.35) were also risk factors for HIV new infections. After controlling other factors, the relationship between the ways of seeking partners and HIV new infection was not statistical significant. Conclusion: Risk factors for HIV new infection among MSM appeared complex and interactive, suggesting that further studies are needed to generate tailored strategies for the prevention of HIV epidemic among MSM population.

The further exploration of hidden blood loss in posterior lumbar fusion surgery

PURPOSE

Hidden blood loss (HBL) plays an important role in lumbar fusion surgery. However, there was huge computation error when calculating hidden loss in previous studies because they regarded the volume of drainage as postoperative blood loss. We should not ignore the fact that the composition of drainage varies from person to person and also with time-lapse after operation. The purpose of this study was to demonstrate a more accurate HBL calculation formula by comparing it with previous formula and to address the importance of HBL in patients undergoing posterior lumbar fusion surgeries.

METHODS

For each patient, the HBL was calculated by previous formula and our recommendable formula. We compared the result of HBL calculated by two different methods. At the same time, we explored the HBL in patients undergoing posterior lumbar fusion surgeries with various levels.

RESULTS

In our study, the average total blood loss was 771ml. The mean intraoperative blood loss was 268ml, and the total volume of post-operative drainage is 276ml. The mean hidden loss of 90 patients calculated with previous method was 227ml and 29.4% of total loss. When taking change of drainage HCT into account, the mean hidden loss calculated with our recommendable method was 362.8ml and 47% of total loss. The results were significantly different (P<0.01). There was no significant difference in the percentage of the HBL between patients with single or multiple surgical levels.

CONCLUSIONS

There is often a substantial unmeasured blood loss in lumbar fusion surgeries. However, the component of drainage changed radically with time, we should take the true blood contained in drainage into considerations when calculating the HBL.

LEVEL OF EVIDENCE

Our research is a case-control study and the level of proof is III.

Disparities in osteoporosis treatments

Osteoporosis treatment rates within 2 years following an index event (fragility fracture, osteoporotic bone mineral density (BMD) T-score, or osteoporosis ICD-9 codes) were determined from 2005 to 2011. Most patients were not treated. Fracture patients had the lowest treatment rate. Low treatment rates also occurred in patients that were male, black, or had non-commercial insurance.

INTRODUCTION

Clinical recognition of osteoporosis (osteoporotic BMD, assignment of an ICD-9 code, or the occurrence of fragility fractures) provides opportunities to treat patients at risk for future fracture.

METHODS

A cohort of 36,965 patients was identified from 2005 to 2011 in the Indiana Health Information Exchange, with index events after age 50 of either non-traumatic fractures, an osteoporosis ICD-9 code, or a BMD T-score ≤ -2.5. Patients with osteoporosis treatment in the preceding year were excluded. Medication records during the ensuing 2 years were extracted to identify osteoporosis treatments, demographics, comorbidities, and co-medications. Predictors of treatment were evaluated in a multivariable logistic regression model.

RESULTS

The cohort was 78 % female, 11 % black, 91 % urban-dwelling, and 53 % commercially insured. The index events were as follows: osteoporosis diagnosis (47 % of patients), fragility fracture (44 %), and osteoporotic T-scores (9 %). Within 2 years after the index event, 23.3 % received osteoporosis medications (of which, 82.2 % were oral bisphosphonates). Treatment rates were higher after osteoporosis diagnosis codes (29.3 %) or osteoporotic T-score (53.9 %) than after fracture index events (10.5 %) (p < 0.001). Age had an inverted U-shaped effect for women with highest odds around 60-65 years. Women (OR 1.86) and non-black patients (OR 1.52) were more likely to be treated (p < 0.001). Patients with public (versus commercial) insurance (OR 0.86, p < 0.001) or chronic comorbidities (ORs about 0.7-0.9, p < 0.001) were less likely to be treated.

CONCLUSION

Most osteoporosis treatment candidates remained untreated. Men, black patients, and patients with fracture or chronic comorbidities were less likely to receive treatment, representing disparity in the recognition and treatment of osteoporosis.

The p53-Bak apoptotic signaling axis plays an essential role in regulating differentiation of the ocular lens

The tumor suppressor p53 is a master regulator of apoptosis and also plays a key role in cell cycle checking. In our previous studies, we demonstrated that p53 directly regulates Bak in mouse JB6 cells (Qin et al. 2008. Cancer Research. 68(11):4150) and that p53-Bak signaling axis plays an important role in mediating EGCG-induced apoptosis. Here, we demonstrate that the same p53-Bak apoptotic signaling axis executes an essential role in regulating lens cell differentiation. First, during mouse lens development, p53 is expressed and differentially phosphorylated at different residues. Associated with p53 expression, Bak is also significantly expressed during mouse lens development. Second, human p53 directly regulates Bak promoter and Bak expression in p53 knockout mice (p53-/-) was significantly downregulated. Third, during in vitro bFGF-induced lens cell differentiation, knockdown of p53 or Bak leads to significant inhibition of lens cell differentiation. Fourth, besides the major distribution of Bak in cytoplasm, it is also localized in the nucleus in normal lens or bFGF-induced differentiating lens cells. Finally, p53 and Bak are co-localized in both cytoplasm and nucleus, and their interaction regulates the stability of p53. Together, these results demonstrate for the first time that the p53-Bak apoptotic signaling axis plays an essential role in regulating lens differentiation.

Temperature-Dependent Magnetic Properties of SiO2-Coated Ni75Fe25 Nanoparticles

SiO2-coated Ni75Fe25 nanoparticles were prepared using a wet chemical method and their structure and magnetic properties were investigated using x-ray diffraction, high-resolution transmission electron microscopy, and a superconducting quantum interference device magnetometer. The SiO2 material was in an amorphous state. The Ni75Fe25 nanoparticles were in a simple cubic state and contained inner oxide (Ni-oxide and Fe-oxide) cores whose size decreased with increasing calcination temperature. The nanoparticles were basically in the ferromagnetic state. Their saturation magnetization increased with increasing calcination temperature, whereas their coercivity decreased with increasing calcination temperature. The nanoparticles exhibited strong temperature-dependent magnetic behaviors. The Bloch exponent fell from 1.5 for the bulk to smaller values and decreased with increasing oxide content, while the Bloch constant was much bigger than that for bulk and increased significantly with oxide content. The value of coercivity decreased with increasing temperature, and this decrease was more pronounced for the nanoparticles containing high oxide content. The exchange anisotropy arising from the exchange coupling across the Ni75Fe25/oxide interfaces was examined and was used to interpret the observed temperature-dependent behaviors.

(E)-N′-(1,3-Benzodioxol-5-ylmethylene)nicotinohydrazide monohydrate

In the title compound, C₁₄H₁₁N₃O₃·H₂O, the planar [maximum deviation 0.135 (1) Å] 1,3-benzodioxole ring system is oriented at a dihedral angle of 13.93 (7)° with respect to the pyridine ring. Extensive inter­molecular N—H⋯O, O—H⋯O, O—H⋯N and weak C—H⋯O hydrogen bonding is present in the crystal structure.

(E)-N′-(3,4-Dichlorobenzylidene)nicotinohydrazide monohydrate

In the title compound, C₁₃H₉Cl₂N₃O·H₂O, the 3,4-dichloro­benzene ring is nearly coplanar with the pyridine ring, making a dihedral angle of 4.78 (8)°. Inter­molecular O—H⋯O, O—H⋯N, N—H⋯O and weak C—H⋯O hydrogen bonding is present in the crystal structure.

Race and sex differences in bone mineral density and geometry at the femur

INTRODUCTION

Differences in osteoporotic hip fracture incidence between American whites and blacks and between women and men are considered to result, in part, from differences in bone mineral density and geometry at the femur. The aim of this study was to quantify differences in femoral bone density and geometry between a large sample of healthy American white and black women and men.

SUBJECTS AND METHODS

Healthy American white (n=612) and black (n=164) premenopausal women, aged 23 to 57 years, and healthy American white (n=492) and black (n=169) men, aged 20 to 63 years, had volumetric bone mineral density (vBMD) and geometry variables measured at the femur by computerized tomography (CT), and areal bone mineral density (aBMD) at femoral neck measured by dual X-ray absorptiometry (DXA).

RESULTS

American blacks had higher vBMD at the femoral neck and femoral shaft cortex than American whites whereas femoral axis length and femoral neck area were not different. Men had lower vBMD at the femoral neck and femoral cortex than women but had greater femoral axis length and femoral neck area than women. The higher aBMD in American blacks than whites persisted after correction for measured area whereas the higher aBMD in men than women disappeared.

CONCLUSIONS

At the femoral neck, American whites have lower bone density than American blacks but similar geometry. Women have higher bone density than men in both races but have smaller geometry variables. The differences in bone density may account in part for the differences in hip fracture incidence between American blacks and whites, whereas the differences in femur size may account for the differences in hip fracture rates between men and women.

PCA and clustering reveal alternate mtDNA phylogeny of N and M clades

Phylogenetic trees based on mtDNA polymorphisms are often used to infer the history of recent human migrations. However, there is no consensus on which method to use. Most methods make strong assumptions which may bias the choice of polymorphisms and result in computational complexity which limits the analysis to a few samples/polymorphisms. For example, parsimony minimizes the number of mutations, which biases the results to minimizing homoplasy events. Such biases may miss the global structure of the polymorphisms altogether, with the risk of identifying a "common" polymorphism as ancient without an internal check on whether it either is homoplasic or is identified as ancient because of sampling bias (from oversampling the population with the polymorphism). A signature of this problem is that different methods applied to the same data or the same method applied to different datasets results in different tree topologies. When the results of such analyses are combined, the consensus trees have a low internal branch consensus. We determine human mtDNA phylogeny from 1737 complete sequences using a new, direct method based on principal component analysis (PCA) and unsupervised consensus ensemble clustering. PCA identifies polymorphisms representing robust variations in the data and consensus ensemble clustering creates stable haplogroup clusters. The tree is obtained from the bifurcating network obtained when the data are split into k = 2,3,4,...,kmax clusters, with equal sampling from each haplogroup. Our method assumes only that the data can be clustered into groups based on mutations, is fast, is stable to sample perturbation, uses all significant polymorphisms in the data, works for arbitrary sample sizes, and avoids sample choice and haplogroup size bias. The internal branches of our tree have a 90% consensus accuracy. In conclusion, our tree recreates the standard phylogeny of the N, M, L0/L1, L2, and L3 clades, confirming the African origin of modern humans and showing that the M and N clades arose in almost coincident migrations. However, the N clade haplogroups split along an East-West geographic divide, with a "European R clade" containing the haplogroups H, V, H/V, J, T, and U and a "Eurasian N subclade" including haplogroups B, R5, F, A, N9, I, W, and X. The haplogroup pairs (N9a, N9b) and (M7a, M7b) within N and M are placed in nonnearest locations in agreement with their expected large TMRCA from studies of their migrations into Japan. For comparison, we also construct consensus maximum likelihood, parsimony, neighbor joining, and UPGMA-based trees using the same polymorphisms and show that these methods give consistent results only for the clade tree. For recent branches, the consensus accuracy for these methods is in the range of 1-20%. From a comparison of our haplogroups to two chimp and one bonobo sequences, and assuming a chimp-human coalescent time of 5 million years before present, we find a human mtDNA TMRCA of 206,000 +/- 14,000 years before present.