Computerized Cognitive Training in Mild Cognitive Impairment: Findings in African Americans and Caucasians

BACKGROUND

African Americans with MCI may be at increased risk for dementia compared to Caucasians. The effect of race on the efficacy of cognitive training in MCI is unclear.

METHODS

We used data from a two-site, 78-week randomized trial of MCI comparing intensive, home-based, computerized training with Web-based cognitive games or Web-based crossword puzzles to examine the effect of race on outcomes. The study outcomes were changes from baseline in cognitive and functional scales as well as MRI-measured changes in hippocampal volume and cortical thickness. Analyses used linear models adjusted for baseline scores. This was an exploratory study.

RESULTS

A total of 105 subjects were included comprising 81 whites (77.1%) and 24 African Americans (22.8%). The effect of race on the change from baseline in ADAS-Cog-11 was not significant. The effect of race on change from baseline to week 78 in the Functional Activities Questionnaire (FAQ) was significant with African American participants' FAQ scores showing greater improvements at weeks 52 and 78 (P = 0.009, P = 0.0002, respectively) than white subjects. Within the CCT cohort, FAQ scores for African American participants showed greater improvement between baseline and week 78, compared to white participants randomized to CCT (P = 0.006). There was no effect of race on the UPSA. There was no effect of race on hippocampal or cortical thickness outcomes.

CONCLUSIONS

Our preliminary findings suggest that web-based cognitive training programs may benefit African Americans with MCI at least as much as Caucasians, and highlight the need to further study underrepresented minorities in AD prevention trials. (Supported by the National Institutes of Health, National Institute on Aging; ClinicalTrials.gov number, NCT03205709.).

Expectancy Does Not Predict 18-month Treatment Outcomes with Cognitive Training in Mild Cognitive Impairment

BACKGROUND

Computerized cognitive training (CCT) has emerged as a potential treatment option for mild cognitive impairment (MCI). It remains unclear whether CCT's effect is driven in part by expectancy of improvement.

OBJECTIVES

This study aimed to determine factors associated with therapeutic expectancy and the influence of therapeutic expectancy on treatment effects in a randomized clinical trial of CCT versus crossword puzzle training (CPT) for older adults with MCI.

DESIGN

Randomized clinical trial of CCT vs CPT with 78-week follow-up.

SETTING

Two-site study - New York State Psychiatric Institute and Duke University Medical Center.

PARTICIPANTS

107 patients with MCI.

INTERVENTION

12 weeks of intensive training with CCT or CPT with follow-up booster training over 78 weeks.

MEASUREMENTS

Patients rated their expectancies for CCT and CPT prior to randomization.

RESULTS

Patients reported greater expectancy for CCT than CPT. Lower patient expectancy was associated with lower global cognition at baseline and older age. Expectancy did not differ by sex or race. There was no association between expectancy and measures of everyday functioning, hippocampus volume, or apolipoprotein E genotype. Expectancy was not associated with change in measures of global cognition, everyday functioning, and hippocampus volume from baseline to week 78, nor did expectancy interact with treatment condition.

CONCLUSIONS

While greater cognitive impairment and increased age was associated with low expectancy of improvement, expectancy was not associated with the likelihood of response to treatment with CPT or CCT.

Increased Expression of Inflammatory Cytokines and Discogenic Neck Pain

OBJECTIVE

Although neck pain has become a serious economic and social problem worldwide, the etiology remains poorly understood. The aim of current study is to explore the possible pathogenesis of discogenic neck pain by analyzing the relationship between inflammatory cytokines and discogenic neck pain and provide a valuable reference for the prevention and treatment of discogenic neck pain.

METHODS

A total of 111 cervical disc samples were collected between October 1, 2021, and October 1, 2022: 38 samples from the discogenic neck pain group, 41 samples from the symptomatic control group, and 32 samples from the normal control group. The concentration of nitric oxide (NO), interleukin (IL)-1, interleukin (IL)-6, and tumor necrosis factor alpha (TNF-α) was determined using the enzyme-linked immunosorbent assay in each sample, and the degeneration degree of the target discs were evaluated using T2-weighted sagittal magnetic resonance imaging (MRI) according to the Miyazaki disc degeneration grading system. Whether the differences among the three groups were statistically significant was tested using one-way analysis of variance and an unpaired t-test, respectively.

RESULTS

The differences of the baseline characteristics were not statistically significant between the discogenic neck pain group and the symptomatic control group (p > 0.05). The expression of inflammatory cytokines in disc samples from the discogenic neck pain group (NO: 9.89 ± 1.75, IL-1β: 10.74 ± 1.92, IL-6:31.65 ± 2.46, and TNF-α: 5.96 ± 1.91) was increased in comparison with the disc samples from both the symptomatic control group (NO: 7.15 ± 2.78, IL-1β: 8.03 ± 1.87, IL-6: 25.79 ± 2.12, and TNF-α: 4.18 ± 2.87) and the normal control group (NO: 6.11 ± 1.37, IL-1β: 5.84 ± 2.25, IL-6: 20.65 ± 1.26, and TNF-α: 2.05 ± 0.58). The differences were statistically significant (p < 0.001). Further, there were no statistical differences in the degree of degeneration between discogenic neck pain group and symptomatic control group.

CONCLUSIONS

The increased expression of inflammatory cytokines in diseased cervical intervertebral discs might play a key role in the pathogenesis of discogenic neck pain. Although inflammation is involved in intervertebral disc degeneration, there is no linear positive correlation between the concentration of inflammatory cytokines and the degree of disc degeneration.

Predictive Factors Associated with Chronic Neck Pain in Patients with Cervical Degenerative Disease: A Retrospective Cohort Study

Purpose

To explore the predictive factors of neck pain (NP) in patients with cervical degenerative disease by retrospectively analyzing their occupational and demographic characteristics and to provide a valuable reference for preventing and treating chronic NP.

Patients and Methods

We retrospectively reviewed the occupational and demographic data of patients with cervical degenerative disease who had undergone anterior cervical surgery between June 2021 and December 2022 at our center. The patients were divided into NP and no-NP groups based on whether they had chronic NP before surgery. Relevant occupational and demographic data from all patients were statistically analyzed, and all variables were made categorical. Forward stepwise logistic regression models were constructed for preoperative chronic neck pain to explore the possible risk factors associated with chronic neck pain.

Results

The differences in smoking, being an office worker, BMI, and disease types between NP and no-NP groups were statistically significant. In contrast, there were no statistically significant in age, sex, academic level, duration, and degeneration grade between the two groups. Moreover, further logistic regression analysis indicated that smoking, being an office worker, having an abnormal BMI, and cervical spondylotic radiculopathy (CSR) were related to chronic neck pain.

Conclusion

The present study indicated that smoking, being an office worker, having an abnormal BMI, and CSR were predisposing risk factors for NP associated with cervical degenerative disease. Although intervertebral disc degeneration is the pathology basis of NP, the degeneration grade was not related to the occurrence of NP in our current study. Therefore, quitting smoking, avoiding sedentariness, and maintaining a normal BMI may prevent NP to some extent.

Post-yield softening of bending-dominated metal metamaterials

Post-yield softening (PYS) plays an important role in guiding the design of high-performance energy-absorbing lattice materials. PYS is usually restricted to lattice materials that are stretching-dominated according to the Gibson-Ashby model. Contrary to this long-held assumption, this work shows that PYS can also occur in various bending-dominated Ti-6Al-4 V lattices with increasing relative density. The underlying mechanism for this unusual property is elucidated using the Timoshenko-beam theory. It is attributed to the increase in stretching and shear deformation with increasing relative density, thereby increasing the tendency towards PYS. The finding of this work extends perspectives on PYS for the design of high-performance energy-absorbing lattice materials.

Post-yield softening of bending-dominated metal metamaterials

Post-yield softening (PYS) plays an important role in guiding the design of high-performance energy-absorbing lattice materials. PYS is usually restricted to lattice materials that are stretching-dominated according to the Gibson-Ashby model. Contrary to this long-held assumption, this work shows that PYS can also occur in various bending-dominated Ti-6Al-4V lattices with increasing relative density. The underlying mechanism for this unusual property is elucidated using the Timoshenko-beam theory. It is attributed to the increase in stretching and shear deformation with increasing relative density, thereby increasing the tendency towards PYS. The finding of this work extends perspectives on PYS for the design of high-performance energy-absorbing lattice materials.

Biological Characteristics of Listeria monocytogenes Following Deletion of TatD-like Protein Gene

TatD is the subunit of the twin-arginine translocation (Tat) pathway. Members of TatD family are multifunctional, conserved and widely presented proteins in most prokaryotes. It has been reported that Tat can affect bacterial motility in some bacteria. This study was conducted to determine the contribution of the TatD protein (herein named LmTatD) to the regulation of flagella in Listeria monocytogenes. We constructed an LmTatD gene mutant in L. monocytogenes strain 10403 s and evaluated its biological characteristics. The results showed no difference in growth or morphology between the wild-type strain and the ΔLmTatD mutant. Intriguingly, the ΔLmTatD mutant showed impaired swimming motility and flagella structure but increased biofilm formation. Comparative proteomic analysis using tandem mass tag (TMT) combined with liquid chromatography-tandem mass spectrometry (LC‒MS/MS) was performed to determine differentially expressed proteins (DEPs). The results revealed that 134 proteins out of 2228 total proteins identified were differentially expressed, among which 18 proteins were upregulated and 116 proteins were downregulated in the ΔLmTatD mutant. Analysis of DEPs indicated that the reduced expression levels of the proteins related to flagellar assembly in the ΔLmTatD mutant correlate with its characteristics. Compared to the wild-type strain, the most downregulated proteins in the ΔLmTatD mutant included FlaA, FliD, FliR, FlgD, FlgL, and FlgG. Collectively, our data suggest that although LmTatD is not required for growth in L. monocytogenes, loss of LmTatD reduces flagellar production and motility by regulating flagellar assembly-related protein expression.

5'-Nucleotidase is dispensable for the growth of Salmonella Typhimurium but inhibits the bactericidal activity of macrophage extracellular traps

Salmonella enterica serovar Typhimurium (S. Typhimurium) is a zoonotic pathogen that causes severe gastroenteritis. The 5'-nucleotidases of pathogens can dephosphorylate adenosine phosphates, boost adenosine levels and suppress the pro-inflammatory immune response. In our previous study, an extracellular nuclease, 5'-nucleotidase, was identified in the extracellular proteins of S. Typhimurium. However, the nuclease activity and the function of the 5'-nucleotidase of S. Typhimurium have not been explored. In the present study, deletion of the 5'-nucleotidase gene is dispensable for S. Typhimurium growth, even under environmental stress. Fluorescence microscopy revealed that the 5'-nucleotidase mutant induced more macrophage extracellular traps (METs) than the wild type did. Furthermore, recombinant 5'-nucleotidase protein (r5Nuc) could degrade λDNA, and the nuclease activity of r5Nuc was optimum at 37 °C and pH 6.0-7.0. The Mg²⁺ enhanced the nuclease activity of r5Nuc, whereas Zn²⁺ inhibited it. Meanwhile, deletion of the 5'-nucleotidase gene increased the bactericidal activity of METs, and r5Nuc could degrade METs and inhibit the bactericidal activity of METs. In conclusion, S. Typhimurium growth was independent of 5'-nucleotidase, but the nuclease activity of 5'-nucleotidase assisted S. Typhimurium to evade macrophage-mediated extracellular killing through degrading METs.

Pathogen-Derived Nucleases: An Effective Weapon for Escaping Extracellular Traps

Since the 2004 publication of the first study describing extracellular traps (ETs) from human neutrophils, several reports have shown the presence of ETs in a variety of different animals and plants. ETs perform two important functions of immobilizing and killing invading microbes and are considered a novel part of the phagocytosis-independent, innate immune extracellular defense system. However, several pathogens can release nucleases that degrade the DNA backbone of ETs, reducing their effectiveness and resulting in increased pathogenicity. In this review, we examined the relevant literature and summarized the results on bacterial and fungal pathogens and parasites that produce nucleases to evade the ET-mediated host antimicrobial mechanism.

Robust bulk micro-nano hierarchical copper structures possessing exceptional bactericidal efficacy

Conventional copper (Cu) metal surfaces are well recognized for their bactericidal properties. However, their slow bacteria-killing potency has historically excluded them as a rapid bactericidal material. We report the development of a robust bulk superhydrophilic micro-nano hierarchical Cu structure that possesses exceptional bactericidal efficacy. It resulted in a 4.41 log₁₀ reduction (>99.99%) of the deadly Staphylococcus aureus (S. aureus) bacteria within 2 min vs. a 1.49 log₁₀ reduction (96.75%) after 240 min on common Cu surfaces. The adhered cells exhibited extensive blebbing, loss of structural integrity and leakage of vital intracellular material, demonstrating the rapid efficacy of the micro-nano Cu structure in destructing bacteria membrane integrity. The mechanism was attributed to the synergistic degradation of the cell envelope through enhanced release and therefore uptake of the cytotoxic Cu ions and the adhesion-driven mechanical strain due to its rapid ultimate superhydrophilicity (contact angle drops to 0° in 0.18 s). The scalable fabrication of this micro-nano Cu structure was enabled by integrating bespoke precursor alloy design with microstructure preconditioning for dealloying and demonstrated on 2000 mm² Cu surfaces. This development paves the way to the practical exploitation of Cu as a low-cost antibiotic-free fast bactericidal material.

[The 486th case: chronic diarrhea and orthostatic hypotension]

A 57-year-old man was admitted to hospital with diarrhea for 10 months and dizziness for 4 months. The patient had 1-2 liters watery stool per day, without pyogenic blood or abnormality in gastroenteroscopy examination. The level of hemoglobin and albumin was generally normal, and fasting test was positive. At the same time, he was accompanied with hyperalgesia of lower limbs and orthostatic hypotension. After the discussion of multiple disciplinary teams, the patient was diagnosed with amyloidosis by sural nerve biopsy, myocardial MRI, and the assays of urine immunoelectrophoresis and serum free light chain. Light chain amyloidosis was confirmed after excluded the diagnosis of familial amyloidosis. The patient was improved after courses of chemotherapy with melphalan and dexamethasone.

Down-regulation of long noncoding RNA PGM5-AS1 correlates with tumor progression and predicts poor prognosis in clear cell renal cell carcinoma

OBJECTIVE

Growing studies have shown that long non-coding RNAs (lncRNAs) have critical regulatory roles in tumorigenesis. Recently, a newly identified lncRNA, Homo sapiens PGM5 antisense RNA 1 (PGM5-AS1), was found to be dysregulated in several tumors. However, its roles in clear cell renal cell carcinoma (ccRCC) have not been investigated. The aim of the present study was to clarify the clinical significance of PGM5-AS1 in ccRCC patients.

PATIENTS AND METHODS

The PGM5-AS1 expression levels were evaluated in 182 primary ccRCC patients using quantitative real-time PCR assays. The associations between expression of PGM5-AS1, clinicopathological parameters, and prognosis of ccRCC were examined using Chi-square test, Kaplan-Meier assays, and multivariate assays.

RESULTS

The expressions of PGM5-AS1 in cancer specimens were lower than those in matched non-tumor specimens from the ccRCC patient (p<0.05). Downregulation of PGM5-AS1 was closely associated with more advanced clinical features, including lymph nodes metastasis (p=0.007) and distant metastasis (p=0.037). A clinical study revealed that ccRCC patients with lower PGM5-AS1 expressions had substantially shorter overall survival (OS) and disease-free survival (DFS) than patients with higher PGM5-AS1 expressions. Further multivariate assays demonstrated that PGM5-AS1 was identified as an independent prognostic factor for patients with ccRCC.

CONCLUSIONS

Down-regulation of PGM5-AS1 in ccRCC tissues had a strong association with unfavorable outcomes and PGM5-AS1 might be a potential tumor suppressor.

A high-power, high-repetition-rate THz source for pump-probe experiments at Linac Coherent Light Source II

Experiments using a THz pump and an X-ray probe at an X-ray free-electron laser (XFEL) facility like the Linac Coherent Light Source II (LCLS II) require frequency-tunable (3 to 20 THz), narrow bandwidth (∼10%), carrier-envelope-phase-stable THz pulses that produce high fields (>1 MV cm^-1) at the repetition rate of the X-rays and are well synchronized with them. In this paper, a two-bunch scheme to generate THz radiation at LCLS II is studied: the first bunch produces THz radiation in an electromagnet wiggler immediately following the LCLS II undulator that produces X-rays from the second bunch. The initial time delay between the two bunches is optimized to compensate for the path difference in THz transport. The two-bunch beam dynamics, the THz wiggler and radiation are described, as well as the transport system bringing the THz pulses from the wiggler to the experimental hall.

[Anti-myelin-associated glycoprotein antibody positive IgM monoclonal gammopathy related peripheral neuropathy: 11 cases and literature review]

目的

提高对罕见的抗髓鞘相关糖蛋白（MAG）抗体阳性的IgM相关性周围神经病（IgM-PN）的认识。

方法

总结2014年1月至2019年4月北京协和医院诊断的11例抗MAG抗体阳性的IgM-PN患者的临床特点、实验室检查、治疗方案和预后。

结果

11例患者中，男8例，女3例，中位发病年龄63（52~77）岁。其中9例患者以远端肢体麻木起病，6例伴肌力减退。神经传导速度检查示，均为周围神经脱髓鞘损害，以下肢感觉神经损害为主，6例伴慢性轴索损害。11例患者均存在血清IgM型单克隆免疫球蛋白，6例为IgM κ型，3例为IgM λ型，2例为IgM κ/IgG κ双克隆型。3例患者继发于巨球蛋白血症。11例患者的血清抗MAG抗体均为阳性。9例患者接受利妥昔单抗单药或联合化疗，治疗后7例患者的神经症状稳定或改善。

结论

抗MAG抗体阳性的IgM-PN是一种罕见的M蛋白相关性疾病。对于伴IgM型M蛋白的周围神经病患者，应常规筛查抗MAG抗体。基于利妥昔单抗的治疗可作为其一线治疗方案。

Serum calprotectin correlates with risk and disease severity in psoriasis patients and the decrease of calprotectin predicts better response to tumor necrosis factor inhibitors

OBJECTIVE

This study aimed to investigate the correlation of serum calprotectin expression with risk and severity of psoriasis, as well as its predictive value for clinical response to tumor necrosis factor inhibitors (TNFi) treatment in psoriasis patients.

PATIENTS AND METHODS

72 psoriasis patients and 70 health controls (HCs) were enrolled. Blood samples were collected, and serum calprotectin was determined by commercial enzyme-linked immuno sorbent assay (ELISA). All patients were treated by TNFi treatment, and followed up at 6 months, and the last follow-up date was 2016/11.

RESULTS

Calprotectin level was elevated in psoriasis patients compared to HCs (p < 0.001), and it disclosed a good diagnostic value of psoriasis with area under curve (AUC) 0.872, 95% CI: 0.810-0.935. Calprotectin expression was positively associated with Psoriasis Area and Severity Index (PASI) score (R = 0.452, p < 0.001), while it was not associated with BSA (R = 0.125, p = 0.297). 58.3% patients achieved PASI75 and 43.1% patients achieved PASI90 at M6. Calprotectin was decreased during the 6-month treatment (p < 0.001). Changes of calprotectin during the first month (∆calprotectin (M0-M1)) in PASI75 group were more than that of non-PASI75 group (p < 0.001). Also, multivariate logistic analysis revealed that ∆calprotectin (M0-M1) (p = 0.001) was an independent factor for PASI75 achievement at M6 after TNFi treatment, while pre-systemic biologic treatment (p = 0.001) was an independent factor for non-PASI75 achievement.

CONCLUSIONS

Serum calprotectin expression is correlated with risk and severity of psoriasis, and the decrease of calprotectin during the first month could predict better clinical response to TNFi treatment in psoriasis patients.

Osteoblast Responses to Titanium-Coated Subcellular Scaled Microgrooves

Statistical data have consistently shown that implant loosening is a significant causative factor for revision surgeries. Both in vivo and in vitro studies have confirmed the positive influences of microgrooved titanium implant surfaces on improving orthopedic titanium implants compared with a smooth titanium surface. Complete cell-groove adhesion is a prerequisite for rapid and robust osseointegration. For the first time, this work has quantified the influence of the titanium groove width at the subcellular scale (5-20 μm) on osteoblast responses, using titanium-coated microgrooved silicon wafer specimens (surface roughness, R_a = ∼1.5 nm), which can avoid the latent influence of variations in surface roughness from the use of normal titanium substrates. The cell-groove adhesion increased from 53.07% to 98.55% with an increasing groove width from 5 to 20 μm. In addition, both the cell spreading area and cell width were proportional to groove width. However, no statistically significant influence (p > 0.05) of groove width was identified on cell proliferation and differentiation. An exponential model was proposed to predict the groove geometries that can facilitate complete cell-groove adhesion. The underlying mechanisms were discussed. The experimental findings of this study provide a unique basis for the design of titanium implant surfaces.

[Prevalence and quality of spirometry and the impact of spirometry training in Hunan, People's Republic of China]

Objective: To explore quality of spirometry in Hunan province and the impact of education on it. Methods: Cross-sectional study and a prospective randomized cohort study. (1) A total of 460 public hospitals in Hunan province were investigated. Research assistants collected 20 consecutive reports of pulmonary ventilation test reports (PVTRs) and basal information of those hospitals which owned spirometry. (2) To measure the effect of education, 28 randomly selected 2(nd) level hospitals which owned spirometry were randomized to intervention and control group (1∶1). The intervention group received a short-time training which included face-to-face lectures and a hand-by-hand operation training course, while the control group received usual care. PVTRs were investigated 3 months after the intervention. All PVTRs were classified to grade A, B, C, D and E according to the Chinese pulmonary ventilation test (PVT) guidelines. Results: The recovery rate was 100%. The spirometry-equipped ratio was 1.6% (2/129) at 1(st) level hospitals, 39.0% (105/269) at 2(nd) level hospitals, 100% (62/62) at 3(rd) level hospitals in Hunan province. There were 100% (2/2), 91.4% (96/105) and 93.5% (58/62) utilization rate at 1(st), 2(nd) and 3(rd) level hospitals. Common reasons for not owning a spirometer were equipment cost and insufficient insurance. Lack of knowledge about spirometry and inadequate benefits were the top two reasons for low utilization rate. There were 3 120 PVTRs from 156 hospitals which used spirometry, a total of 50.4% (1 574/3 120) PVTRs got grade A, a total of 14.8% (462/3 120) PVTRs were judged as unreliable (grade D, E). There were 560 PVTRs and 28 questionnaires, respectively, before and after intervention. The technicians' knowledge improved after education compared to before (9.8±0.6 vs 8.6±1.1) (P<0.05). And 75.0% (210/280) PVTRs got A grade in the intervention group, which was significantly higher than those in the control group (75.0% vs 37.9%, P<0.05). While none of PVTRs was unreliable, which was lower than that in the control group (0 vs 14.6%, P<0.05). Conclusions: The equipment ratio and the utilization rate of spirometry are still low and imbalanced among three levels hospitals in Hunan. The short-time training is helpful to improve quality of spirometry.

Prevalence of Cerebral Microhemorrhage following Chronic Blast-Related Mild Traumatic Brain Injury in Military Service Members Using Susceptibility-Weighted MRI

BACKGROUND AND PURPOSE

Cerebral microhemorrhages are a known marker of mild traumatic brain injury. Blast-related mild traumatic brain injury relates to a propagating pressure wave, and there is evidence that the mechanism of injury in blast-related mild traumatic brain injury may be different from that in blunt head trauma. Two recent reports in mixed cohorts of blunt and blast-related traumatic brain injury in military personnel suggest that the prevalence of cerebral microhemorrhages is lower than in civilian head injury. In this study, we aimed to characterize the prevalence of cerebral microhemorrhages in military service members specifically with chronic blast-related mild traumatic brain injury.

MATERIALS AND METHODS

Participants were prospectively recruited and underwent 3T MR imaging. Susceptibility-weighted images were assessed by 2 neuroradiologists independently for the presence of cerebral microhemorrhages.

RESULTS

Our cohort included 146 veterans (132 men) who experienced remote blast-related mild traumatic brain injury (mean, 9.4 years; median, 9 years after injury). Twenty-one (14.4%) reported loss of consciousness for <30 minutes. Seventy-seven subjects (52.7%) had 1 episode of blast-related mild traumatic brain injury; 41 (28.1%) had 2 episodes; and 28 (19.2%) had >2 episodes. No cerebral microhemorrhages were identified in any subject, as opposed to the frequency of SWI-detectable cerebral microhemorrhages following blunt-related mild traumatic brain injury in the civilian population, which has been reported to be as high as 28% in the acute and subacute stages.

CONCLUSIONS

Our results may reflect differences in pathophysiology and the mechanism of injury between blast- and blunt-related mild traumatic brain injury. Additionally, the chronicity of injury may play a role in the detection of cerebral microhemorrhages.

An interpretable health behavioral intervention policy for mobile device users

An increasing number of people use mobile devices to monitor their behavior, such as exercise, and record their health status, such as psychological stress. However, these devices rarely provide ongoing support to help users understand how their behavior contributes to changes in their health status. To address this challenge, we aim to develop an interpretable policy for physical activity recommendations that reduce a user's perceived psychological stress, over a given time horizon. We formulate this problem as a sequential decision-making problem and solve it using a new method that we refer to as threshold Q-learning (TQL). The advantage of the TQL method over traditional Q-learning is that it is "doubly robust" and interpretable. This interpretability is achieved by making model assumptions and incorporating threshold selection into the learning process. Our simulation results indicate that the TQL method performs better than the Q-learning method given model misspecification. Our analyses are performed on data collected from 79 healthy adults over a 7 week period, where the data comprise physical activity patterns collected from mobile devices and self-assessed stress levels of the users. This work serves as a first step toward a computational health coaching solution for mobile device users.

The effect of ordered and partially ordered surface topography on bone cell responses: a review

Current understanding of the role of ordered and partially ordered surface topography in bone cell responses for bone implant design.

Role of ultrasonic treatment, inoculation and solute in the grain refinement of commercial purity aluminium

The present study investigates the influence of ultrasonic treatment on the grain refinement of commercial purity aluminium with a range of Al3Ti1B master alloy additions. When the aluminium contains the smallest amount of added master alloy, ultrasonics caused significant additional grain refinement compared to that provided by the master alloy alone. However, the influence of ultrasonics on grain size reduces with increasing addition of the master alloy which adds additional TiB₂ particles and Ti solute with each incremental addition. Applying the Interdependence model to analyse the experimentally measured grain sizes revealed that the results of this study and those from similar experiments on an Al-2Cu alloy were consistent when the alloy compositions are converted to their growth restriction factors (Q) and that increasing Q had a major effect on reducing grain size and increasing grain number density. Compared with the application of ultrasonic treatment where an order of magnitude increase in the grain number density is achieved, an increase in the Ti content over the range of master alloy additions, causes the grain number density to increase by approximately three times.

Study of three types of desensitizers in dentin bonding strength

One hundred and twenty human molars without decay (premolars and complete third molars) freshly extracted for orthodontic purposes were used in the study to explore the impact of application of three kinds of desensitizers on self-etching/all-etching bond strength of dentin. The roots were ground along the cementoenamel junction (CEJ), the residual crowns were divided into two parts along mesial and distal direction, and the enamel layer was removed. The dentin was ground into standard pieces of 3x3x3 mm and then polished using alumina waterproof abrasive paper. Two hundred and forty specimens were divided into two groups according to self-etching bond (OptiBond, iBond, XenoIV) and all-etching bond (OptiBond, iBond, Probond). Each of the two groups were subdivided into three groups with different brands, and then further subdivided into three experimental groups and a control group (10 samples in each final group). The surface of dentin coated with desensitizer was examined using scanning electron microscope. Results showed that only the shear strength of iBond + Ddes + Z100 resin group was lower compared to the control group (P < 0.05). The comparison of the resin shear strength in other experimental groups with the control groups demonstrated no statistically significant difference (P > 0.05). The shear strength of Optibond + Gluma, Optibond + Ddes, iBond + Ddes + Z100 resin group in all-etching bond group and the experimental groups in Probond group was lower than in the control group (P < 0.05). The resin shear strength in other groups did not differ from the controls (P > 0.05).

The effects of water on degradation of the zirconia-resin bond

OBJECTIVES

10-methacryloyloxydecyldihydrogenphosphate (MDP) containing primers improve bonding of yttria-stabilised tetragonal zirconia (Y-TZP) to methacrylate resins. The present study investigated the role played by water in the deterioration of MDP-mediated zirconia-resin bonds.

METHODS

Grit-blasted Y-TZP plates were conditioned with two MDP primers and bonded with resin for shear bond strength (SBS) testing. Additional bonded plates were aged hydrothermally and compared with unaged Y-TZP after 24h of water-storage or 6 months of water/acid/alkali-storage. The monoclinic phase (m-ZrO₂) in different groups was determined by X-ray diffraction. Hydrolytic stability of the coordinate bond between MDP and zirconia in neutral/acid/alkaline environment was analysed using thermodynamic calculations. Microleakage and release of the element phosphorus from MDP-mediated Y-TZP/resin-bonded interfaces were evaluated via methylene blue dye infiltration and inductively coupled plasma-mass spectrometry (ICP-MS).

RESULTS

Hydrothermal ageing did not significantly alter SBS. Ageing in acidic or neutral medium led to significant decline in SBS. The m-ZrO₂ phase increased after hydrothermal ageing but no m-ZrO₂ was detected in the water/acid/alkali-aged specimens. A higher equilibrium constant was identified in the MDP-t-ZrO₂ complex when compared with the MDP-m-ZrO₂ complex. MDP-conditioning failed to prevent infiltration of the methylene blue dye. Phosphorus was detected by ICP-MS from the solutions used for soaking the resin-bonded specimens.

CONCLUSIONS

Hydrolysis of the coordinate bond between MDP and ZrO₂, rather than t→m phase transformation, weakens the bond integrity between MDP-conditioned Y-TZP and methacrylate resin.

CLINICAL SIGNIFICANCE

Hydrolysis of the coordinate bond between MDP and zirconia is responsible for deterioration of the integrity of the bond between MDP-conditioned Y-TZP and methacrylate resin.

Osteogenesis-promoting activity of composites SBA-15 mesoporous particles carrying oxytocin in vitro and in vivo

This study analyzes the performance of SBA-15 mesoporous particles carrying oxytocin (OT) in promoting osteogenesis in vitro and in vivo. The SBA-15 particles synthesized in the previous studies (about 30 μm in diameter and containing 10 nm deep pores) were loaded with the drug oxytocin and cultured with human osteosarcoma MG-63 cell line in vitro. The influence of particles on cell proliferation was studied. The level of the osteogenic marker (alkaline phosphatase and type I collagen) was measured. For in vivo studies, the connectivity defects of rabbit skull were prepared, and SBA-15 suspensions were regularly injected at the defect sites. The changes in the defect site calcium salt deposition were measured, and morphological changes were observed by microscopy. The material had to promote effect on osteogenesis-related indicators such as alkaline phosphatase and collagen I in bone sarcoma cell line MG-63. In vivo, the calcium salt deposition in OT/SBA-15 group was significantly higher than in the blank group. SBA-15 carriers appeared to persist in the region of the defect after the injection and release the drugs slowly, thus playing a more distinct role in promoting bone repair of local bone defects. The results showed that SBA-15 particles with OT could slow the release drugs and could help in promoting osteogenesis.

Bronchial lavage P 16INK4A gene promoter methylation and lung cancer diagnosis: A meta-analysis

OBJECTIVE

To evaluate the diagnostic value of bronchial lavage P16INK4A promoter methylation and lung cancer.

MATERIALS AND METHODS

The databases of PubMed, Medline, China National Knowledge Infrastructure, and Wanfang were electronically searched by two reviewers to find the suitable studies related to the association between P16INK4A promoter methylation and lung cancer. The P16INK4A promoter methylation rate was extracted from each included individual study. The diagnostic sensitivity, specificity, and area under the receiver operating characteristic ROC curve of bronchial lavage P16INK4Aas a biomarker for diagnosis of lung cancer were pooled by stata 11.0 software (Stata Corporation, College Station, TX, USA).

RESULTS

At last, 10 publications were included in this meta-analysis. Of the included 10 studies, five are published in English with relatively high quality and other five papers published in Chinese have relatively low quality. The pooled sensitivity and specificity of bronchial lavage P16INK4A promoter methylation for lung cancer diagnosis were 0.61 (95% confidence interval [CI]: 0.57-0.65) and 0.81 (95% CI: 0.78-0.85), respectively, with random effect model. The ROC curve were calculated and drawn according to Bayes' theorem by stata 11.0 software. The systematic area under the ROC was 0.72 (95% CI: 0.68-0.76), which indicated that the diagnostic value of bronchial lavage P16INK4A promoter methylation for lung cancer was relatively high. Moreover, no significant publication bias was existed in this meta-analysis (t = 0.69, P > 0.05).

CONCLUSION

Bronchial lavage P16INK4A promoter methylation can be a potential biomarker for diagnosis of lung cancer.

Pediatric tuberculosis drug market: an insider perspective on challenges and solutions

Representative stakeholders were consulted on how they felt access to pediatric tuberculosis (TB) drugs could be improved. A key recommendation is the development of new child-friendly, adequately dosed formulations with a good shelf life in all climate zones. There is also an urgent need to improve the diagnosis and reporting of children with TB. Manufacturers of pediatric TB medications are to be incentivized through improved coordination among all stakeholders, with streamlined regulatory approvals and increased consumer education on drug and regimen guidelines. Finally, pooled procurement is advised to ensure sustained market supply against affordable prices.

[Assessment of Influence Detective Position Variability on Precision of Near Infrared Models for Soluble Solid Content of Watermelon]

Non-destructive detection for soluble solids content (SSC) is important to improve watermelon’s internal quality, which attracts more and more attention from consumers. In order to realize the precise detection for SSC of mini watermelon’s whole surface by using Near-infrared (NIR) spectroscopy and reduce the influence of detective position variability on the accuracy of NIR prediction model for SSC, the diffused transmission spectra and soluble solids content were collected from three different detective positions of ‘jingxiu’ watermelon, including the equator, calyx and stem. The prediction models of single detective position and mixed three detective positions for SSC were established with Partial least square (PLS). Successive projections algorithm (SPA) and competitive adaptive reweighted sampling (CARS) were adopted to select effective variables of NIR spectroscopy for SSC of watermelon as well. The results showed that the prediction model of mixed three detective positions was better than the model of single detective position. Meanwhile, 42 characteristic variables of NIR spectroscopy selected with CARS were used to establish PLS prediction model for SSC. The prediction model was simplified significantly and the prediction accuracy for SSC was improved greatly. The correlation coefficient of prediction (RP) and root mean square error of prediction (RMSEP) by CARS-PLS were 0.892, 0.684 °Brix for the equator, 0.905, 0.621 °Brix for the calyx, 0.899, 0.721 °Brix for the stem, respectively. However, the prediction result of SPA-PLS established by 19 characteristic wavelength variables of NIR spectroscopy was bad for the equator, calyx and stem detective positions. The correlation coefficient of prediction (RP) is less than 0.752 and root mean square error of prediction (RMSEP) is relatively high. It was proposed that the PLS prediction model established by mixed three different detective positions with effective characteristic wavelength variables selected by CARS can improve the prediction accuracy for SSC. And the CARS-PLS prediction model can achieve fast and precise detection for SSC of mini watermelon’s whole surface. The influence of detective position variability on the accuracy of NIR prediction model could be reduced simultaneously. This paper could provide theoretical basis for calibrating NIR prediction model for SSC of mini watermelon. It also could provide reference for developing the portable and non-destructive detection equipment for soluble solids content of mini watermelon’s whole surface.

Topological design and additive manufacturing of porous metals for bone scaffolds and orthopaedic implants: A review

One of the critical issues in orthopaedic regenerative medicine is the design of bone scaffolds and implants that replicate the biomechanical properties of the host bones. Porous metals have found themselves to be suitable candidates for repairing or replacing the damaged bones since their stiffness and porosity can be adjusted on demands. Another advantage of porous metals lies in their open space for the in-growth of bone tissue, hence accelerating the osseointegration process. The fabrication of porous metals has been extensively explored over decades, however only limited controls over the internal architecture can be achieved by the conventional processes. Recent advances in additive manufacturing have provided unprecedented opportunities for producing complex structures to meet the increasing demands for implants with customized mechanical performance. At the same time, topology optimization techniques have been developed to enable the internal architecture of porous metals to be designed to achieve specified mechanical properties at will. Thus implants designed via the topology optimization approach and produced by additive manufacturing are of great interest. This paper reviews the state-of-the-art of topological design and manufacturing processes of various types of porous metals, in particular for titanium alloys, biodegradable metals and shape memory alloys. This review also identifies the limitations of current techniques and addresses the directions for future investigations.

Development of a new benazepril hydrochloride chewable tablet and evaluation of its bioequivalence for treatment of heart failure in dogs

The aim of the study was to develop a new chewable benazepril hydrochloride(BH) tablet, investigate its physical properties, and evaluate its bioequivalence with the branded formulation (Fortekor). A corrective agent was included in the formula to improve its palatability and convenience for administration to dogs. The tablet remained stable in light, heat, and humidity tests, and its physical properties such as hardness, uniformity of content, and dissolution rate were highly consistent with the technical standards. After single and repeated administrations to eight beagles and single dose to 14 mongrel dogs (0.5 mg/kg p.o.), plasma BH and its active metabolite, benazeprilat (BZ), were detected. There was no significant difference in the major pharmacokinetic parameters (Cmax , Tmax, and AUC₀₋₂₄) between the two formulations. The 90% confidence intervals calculated for the ratios of area under the time-concentration curve (AUC₀₋₂₄) were 92.4-116.3% for BH and 89.9-102.3% for BZ, within the accepted range for bioequivalence of 80-125%. The results showed our new chewable tablet is bioequivalent to the commercial product and suitable for addition to the benazepril product family for the treatment of heart failure in dogs.

Postural change from lateral to supine is an important mechanism enhancing cephalic spread after injection of intrathecal 0.5% plain bupivacaine for cesarean section

BACKGROUND

Spinal anesthesia is widely used for cesarean section, but the factors that affect the spread of the block in pregnant patients are still not fully explained. This study was designed to investigate the effect of postural changes on sensory block level.

METHODS

Thirty patients scheduled for elective cesarean section under combined spinal-epidural anesthesia were randomly allocated into three groups. After intrathecal injection of 0.5% plain bupivacaine 7.5mg, patients in group S were immediately placed in the supine position with left tilt, patients in group L5 were kept lateral for 5 min and then turned to the supine position with left tilt, and patients in group L10 were kept lateral for 10 min and then turned to the supine position with left tilt.

RESULTS

At 5 min, median cephalad level of sensory block was lower in groups L5 and L10 compared with group S (corrected P<0.001); at 10 min, median cephalad sensory block level was lower in group L10 compared with group S (corrected P<0.001) and group L5 (corrected P<0.001), and lower in group L5 compared with group S (corrected P=0.033); at 15 min, median cephalad level of sensory block was lower in group L10 compared with group S (corrected P=0.003) and group L5 (corrected P=0.015).

CONCLUSIONS

In our population, using 0.5% plain bupivacaine 7.5mg, postural change from the lateral position to the supine position is an important mechanism enhancing cephalic spread of spinal anesthesia during late pregnancy.

Concurrence of de-alloying and re-alloying in a ternary Al67Cu18Sn15 alloy and the fabrication of 3D nanoporous Cu–Sn composite structures

The creation of nanoporous Cu₃Sn–Cu–Cu₆Sn₅ composite structures in the form of self-supporting foils through the concurrence of de-alloying and re-alloying.

Impacts of trace carbon on the microstructure of as-sintered biomedical Ti-15Mo alloy and reassessment of the maximum carbon limit

The formation of grain boundary (GB) brittle carbides with a complex three-dimensional (3-D) morphology can be detrimental to both the fatigue properties and corrosion resistance of a biomedical titanium alloy. A detailed microscopic study has been performed on an as-sintered biomedical Ti-15Mo (in wt.%) alloy containing 0.032 wt.% C. A noticeable presence of a carbon-enriched phase has been observed along the GB, although the carbon content is well below the maximum carbon limit of 0.1 wt.% specified by ASTM Standard F2066. Transmission electron microscopy (TEM) identified that the carbon-enriched phase is face-centred cubic Ti2C. 3-D tomography reconstruction revealed that the Ti2C structure has morphology similar to primary α-Ti. Nanoindentation confirmed the high hardness and high Young's modulus of the GB Ti2C phase. To avoid GB carbide formation in Ti-15Mo, the carbon content should be limited to 0.006 wt.% by Thermo-Calc predictions. Similar analyses and characterization of the carbide formation in biomedical unalloyed Ti, Ti-6Al-4V and Ti-16Nb have also been performed.

Calibration of temperature measurement by infrared pyrometry in microwave heating of powder materials: an exothermic reaction based approach

Accurate temperature measurement remains a challenge for microwave heating of powder materials. We propose a temperature calibration method based on exothermic reactions and the resultant thermal runaway that occurs during microwave heating. The approach was demonstrated on microwave heating of four titanium alloys. Differential scanning calorimetry was used to determine the threshold reaction temperature for each selected titanium alloy. This served as a standard for the microwave heating of these titanium alloys. Infrared pyrometric temperature measurements were then calibrated by comparing the starting temperature of each thermal runaway event with the threshold reaction temperature.

Fast growth of branched nickel monosilicide nanowires by laser-assisted chemical vapor deposition

Branched nickel monosilicide (NiSi) nanowires (NWs), for the first time, have been synthesized on Ni foams by laser-assisted chemical vapor deposition using disilane precursor molecules. Studies indicate that 600 °C is the threshold temperature for the growth of a large number of branched NiSi NWs with 100-500 nm long branches extending from the main stems. Below the threshold temperature, unbranched NiSi NWs were obtained. The density of the branched NiSi NWs is relatively higher in comparison to that of the unbranched ones. The growth rate of the branched NiSi NWs at 700 °C is estimated up to 10 µm min(-1). High-resolution transmission electron microscopy and energy-dispersive x-ray spectroscopy of the branched NiSi NWs suggest that the formation of these branched nanostructures is ascribed to the Ni-dominant diffusion process. These NiSi NWs with branched nanostructures could bring them new opportunities in nanodevices.

Gadolinium Solubility Limits in Sodium-Aluminoborosilicate Glasses

Gadolinium and lanthanum solubility limits in a sodium-alumino-borosilicate glass system were studied. As melting temperature increased from 1400°C to 1450°C, 1500°C and 1550°C, the solubility of gadolinium in the baseline glass 15B2O3-5A12O3-20Na2O-60SiO2 (in molar composition) increased from 10.1 to 11.3, 12.2 and 13.1 (in mole percent of Gd2O3). The enthalpy change of Gd2O3 dissolution in this baseline glass is about 43.6 kJ/mol. Boron effect on lanthanum solubility was studied using the following baseline glasses: xB2O3-20Na2O- 5Al2O3-60SiO2, where x equals to 5, 10, 15, and 20, respectively. It was found that lanthanum solubility limit increased from 8.4 to 10.3, 12.5 and 14.9 (in mole percent of La2O3) as B2O3 increased from 5.1 to 9.5, 13.1 and 16.2 mol%. Gd2O. and La2O3 have similar solubility limits. Solubility limits of mixtures containing different ratios of Gd2O3 to La2O3 in the baseline glass 15B2O3-20Na2O-5A12O3-60SiO2 were found insensitive to the ratio of La/Gd. As far as gadolinium is concerned, its solubility limit will decrease when other lanthanides are introduced.