Longitudinal antinuclear antibody titers in systemic lupus erythematosus and other rheumatic diseases.

Introduction: Antinuclear antibodies (ANAs) are a key feature of systemic lupus erythematosus (SLE) and marker of subclinical autoimmunity. Little is known about longitudinal ANA titers in individuals from the general population or in predicting clinical disease course in persons with rheumatic diseases. Methods: We performed an exploratory analysis from an academic health system between 1999 and 2020 to assess intra-individual variation in ANAs longitudinally in persons with SLE, other ANA-associated rheumatic diseases, and ANA+ controls without rheumatic disease. Results: Persons with SLE had a higher odds of positive ANA compared to those with other ANA-associated rheumatic diseases [OR 2.10, 95% CI (1.82, 2.43)] controlling for time and demographics (age, sex, race, ethnicity). Compared to ANA+ controls, the ANA titer strength was significantly higher for both the ANA-associated rheumatic disease (0.33 log units higher) and SLE groups (0.42 log units higher) controlling for demographics and time (p < 0.001 for both). Over time from the first positive ANA, titer strength significantly decreased for all three groups, with average monthly decreases ranging between 0.001 to 0.004 log titer units (p ≤ 0.001 for all). Conclusion: Based on this analysis of electronic health data spanning two decades, ANA titers may be more dynamic than previously accepted in patients with SLE and ANA-associated rheumatic diseases, with average titers tending to be higher in early disease and decreasing over time.

Implementation of postoperative opioid prescribing guidelines after carpal tunnel release: a quality collaborative study.

Opioid prescribing after carpal tunnel release (CTR) is not well understood. We assessed CTR opioid prescribing within a quality collaborative after the dissemination of guidelines. Post guidelines, the odds of receiving a prescription decreased by 67%. Quality collaboratives can change practice patterns.Level of evidence: III.

Employer-Sponsored Medicare Advantage Plans and the 2018 Therapy Cap Repeal: Reduced Overall Spending Does Not Constrain Out-of-Pocket Costs.

BACKGROUND: Policy impacting traditional Medicare beneficiaries may have unintended effects for privately insured patients. After the repeal of a longstanding $1500 outpatient therapy cap in 2018, we aimed to evaluate if this policy change was associated with differences in use of cost of postoperative therapy after common hand surgeries, including carpal tunnel release, trigger finger release, ganglion cyst excision, De Quervain tenosynovitis release, carpometacarpal arthroplasty, and distal radius fracture open reduction/internal fixation or percutaneous pinning. METHODS: The Medicare Supplement and Coordination of Benefits files from Marketscan were used. Frequency of therapy appointments, overall costs, and out-of-pocket costs were obtained. A segmented interrupted time series with Poisson and log-transformed linear regression was performed. RESULTS: No significant monthly change in odds of therapy use was found in the postpolicy period for patients who underwent trigger finger release, carpal tunnel release, Ganglion cyst excision, De Quervain tenosynovitis release, carpometacarpal arthroplasty, or distal radius fracture, pinning, or open reduction/internal fixation. Overall cost decreased in the postpolicy period by 2% for comprehensive plans (95% confidence interval [CI]: -0.03 to -0.01, P < 0.001), by 7% for those with exclusive provider organizations (95% CI: -0.10 to -0.04, P < 0.001), by 1% for HMOs (95% CI: -0.01 to 0.002, P = 0.01), and by 3% for preferred provider organizations (95% CI: -0.03 to -0.02, P < 0.001). In the postpolicy period, no monthly change in out-of-pocket cost was observed for patients with comprehensive, exclusive provider organization, health maintenance organization, preferred provider organization, or point of service with capitation insurance plans. CONCLUSIONS: Patients with employer-sponsored Medicare Advantage plans experienced increased out-of-pocket costs for therapy despite lower net costs. These data highlight an urgent need for policy ensuring that patients benefit when overall costs of care decrease.

Bifunctional Chiral Electrocatalysts Enable Enantioselective α-Alkylation of Aldehydes.

Herein, we describe an innovative approach to the asymmetric electrochemical α-alkylation of aldehydes facilitated by a newly designed bifunctional chiral electrocatalyst. The highly efficient bifunctional chiral electrocatalyst combines a chiral aminocatalyst with a redox mediator. It plays a dual role as a redox mediator for electrooxidation, while simultaneously providing remarkable asymmetric induction for the stereoselective α-alkylation of aldehydes. Additionally, this novel catalyst exhibits enhanced catalytic activity and excellent stereoselective control comparable to conventional catalytic systems. As a result, this strategy provides a new avenue for versatile asymmetric electrochemistry. The electrooxidation of diverse phenols enables the C-H/C-H oxidative α-alkylation of aldehydes in a highly chemo- and stereoselective fashion. Detailed mechanistic studies by control experiments and cyclic voltammetry analysis demonstrate possible reaction pathways and the origin of enantio-induction.

Postoperative hand therapy and the 2018 Medicare therapy cap repeal: Appraising cost and use changes.

BACKGROUND: Therapy use is common following carpal tunnel release (CTR), trigger finger release, ganglion cyst excision, De Quervain tenosynovitis release, carpometacarpal arthroplasty, and distal radius fracture, open reduction internal fixation or percutaneous pinning (DRF). Policy that improves coverage influences the cost and use of health care services. PURPOSE: This study aims to evaluate changes to the cost and use of postoperative hand therapy by race and procedure following the repeal of a longstanding annual Medicare outpatient therapy cap. STUDY DESIGN: Retrospective cohort study. METHODS: This is a longitudinal retrospective cohort study using a quasi-experimental interrupted time series design, including patients who underwent common hand surgeries from January 1, 2016-December 31, 2019. RESULTS: This study included 203,672 patients with a mean age of 71.4 years. Neither White (1.00, 95% confidence interval [CI]: 0.999-1.007, p = 0.45) nor non-White (1.00, 95% CI: 1.00-1.01, p = 0.06) patients experienced monthly changes in therapy use before policy implementation. Therapy frequency increased following CTR (odds ratio [OR] 1.12, 95% CI: 1.11-1.14, p < 0.001), trigger finger release (OR 1.09, 95% CI: 1.07-1.10, p < 0.001), and DRF (OR 1.05, 95% CI: 1.03-1.06, p < 0.001) following implementation. CONCLUSIONS: This study found that improved coverage was associated with increased postoperative therapy use among some subsets, including CTR and DRF, suggesting the need to optimize coverage by means such as prior authorization or bundled payments, rather than only increasing coverage benefits.

Stretchable ionic-electronic bilayer hydrogel electronics enable in situ detection of solid-state epidermal biomarkers.

Continuous and in situ detection of biomarkers in biofluids (for example, sweat) can provide critical health data but is limited by biofluid accessibility. Here we report a sensor design that enables in situ detection of solid-state biomarkers ubiquitously present on human skin. We deploy an ionic-electronic bilayer hydrogel to facilitate the sequential dissolution, diffusion and electrochemical reaction of solid-state analytes. We demonstrate continuous monitoring of water-soluble analytes (for example, solid lactate) and water-insoluble analytes (for example, solid cholesterol) with ultralow detection limits of 0.51 and 0.26 nmol cm-2, respectively. Additionally, the bilayer hydrogel electrochemical interface reduces motion artefacts by a factor of three compared with conventional liquid-sensing electrochemical interfaces. In a clinical study, solid-state epidermal biomarkers measured by our stretchable wearable sensors showed a high correlation with biomarkers in human blood and dynamically correlated with physiological activities. These results present routes to universal platforms for biomarker monitoring without the need for biofluid acquisition.

Cimifugin Relieves Histamine-Independent Itch in Atopic Dermatitis via Targeting the CQ Receptor MrgprA3.

Background: We previously found that cimifugin has a potent antiallergic inflammatory effect in atopic dermatitis (AD). However, whether cimifugin has an antipruritic effect in AD was unknown. Methods: Mouse scratching behavior tests were performed to verify the proposed antipruritic effect of cimifugin on DNFB- or FITC-mediated AD. Chloroquine (CQ)- and compound 48/80-evoked acute itch models were employed to clarify the effect of cimifugin on histamine-dependent or -independent itch. Intracellular calcium changes were assessed in a primary culture of mouse dorsal root ganglia (DRG) in response to pruritogen exposure with or without cimifugin treatment, including CQ, histamine, allyl-isothiocyanate (AITC), and capsaicin. Molecular docking and microscale thermophoresis (MST) assays were performed to predict and verify the binding ability and modes between cimifugin and the CQ receptor MrgprA3, respectively. Results: We found that cimifugin attenuates itch behaviors effectively in FITC-induced AD. Notably, cimifugin significantly alleviated acute itching behaviors induced by CQ but not compound 48/80 in vivo. Moreover, cimifugin remarkably inhibited CQ-evoked calcium influx in DRG cells but had no obvious effect on histamine-induced calcium influx. Nevertheless, cimifugin did not interfere with either AITC-stimulated TRPA1 activation- or capsaicin-stimulated TRPV1 activation-mediated calcium influx in DRG cells. Molecular docking predicted that CQ and cimifugin might share similar binding abilities and binding modes with MrgprA3. MST assay confirmed cimifugin directly targeting MrgprA3. Conclusion: The present study demonstrates that cimifugin has a potent antipruritic effect in AD with a histamine-independent mechanism via targeting the CQ receptor MrgprA3. Thus, cimifugin is a promising candidate antipruritic agent for AD.

Post-Bariatric Panniculectomy: Postoperative Complications by Weight Loss Surgery Type.

BACKGROUND: Over 250,000 patients undergo bariatric surgery each year in the United States. Approximately 21% will undergo subsequent body contouring after massive weight loss. Patients with prior bariatric surgery are at a greater risk for complications relative to the general population. However, it is unknown if bariatric surgery type is associated with differential complication risk after panniculectomy. METHODS: A retrospective chart review of post-bariatric who underwent abdominal panniculectomy at a single large quaternary care center was performed. Postoperative complications were graded according to the Clavien-Dindo classification. Descriptive statistics, multivariable logistic regression, and power calculations were performed. RESULTS: In total, 216 patients were included. Restrictive bariatric surgery accounted for 48.6% while 51.3% had a history of malabsorptive bariatric surgery. The overall rate of complications was 34.3% (restrictive: 36.2%; malabsorptive: 32.8%, p=0.66). Wound complications were observed in 25.5% (n=55) of patients. Systemic complications occurred in 11.1% of patients overall, with statistically similar rates between restrictive and malabsorptive groups. After adjusting for both patient and operative factors, no significant difference in total complications (OR=1.15, 95% CI: 0.47 to 2.85, p=0.76), systemic complications (OR=0.26, 95% CI: 0.05 to 1.28, p=0.10), or wound complications (OR=2.31, 95% CI: 0.83 to 6.41, p=0.11) was observed. CONCLUSIONS: Complications following panniculectomy in bariatric surgery patients is high and predominantly related to wound healing. No significant difference between type of bariatric surgery and complication risk was found.

Association of Screen Time with Anxiety and Depressive Symptoms in College Students During COVID-19 Outbreak in Shanghai: Mediation Role of Sleep Quality.

The study aimed to investigate the associations between different types of screen time (ST) and anxiety and depressive symptoms in college students during the Coronavirus disease 2019 (COVID-19) outbreak in Shanghai, China; the potential mediation role of sleep quality was also examined. A total of 1,550 college students completed an online survey in May 2022. ST, Self-rating Anxiety Scale (SAS) score, Self-rating Depression Scale (SDS) score, Pittsburgh Sleep Quality Index (PSQI) score, and physical activity were self-reported. Multiple linear regression and mediation analysis were conducted. The results showed that more time spent in TV/movie viewing (>2 h/day) and recreational reading (>1 h/day) was associated with higher levels of anxiety, while more time spent in online social media (>2 h/day) was associated with a higher level of depressive symptoms. In contrast, time spent in online social media (1-2 h/day) was associated with a lower level of anxiety. Meanwhile, recreational reading (2-3 h/day) had a significant indirect effect on anxiety and depressive symptoms through sleep quality. During the COVID-19 outbreak, the associations of ST with anxiety and depressive symptoms varied by the type of screen viewing in college students. The associations of slightly excessive time spent on recreational reading with higher levels of anxiety and depressive symptoms were partially mediated by sleep quality.

Dual-Conductive and Stiffness-Morphing Microneedle Patch Enables Continuous In Planta Monitoring of Electrophysiological Signal and Ion Fluctuation.

The use of conductive microneedles presents a promising solution for achieving high-fidelity electrophysiological recordings with minimal impact on the interfaced tissue. However, a conventional metal-based microneedle suffers from high electrochemical impedance and mechanical mismatch. In this paper, we report a dual-conductive (i.e., both ionic and electronic conductive) and stiffness-morphing microneedle patch (DSMNP) for high-fidelity electrophysiological recordings with reduced tissue damage. The polymeric network of the DSMNP facilitates electrolyte absorption and therefore allows the transition of stiffness from 6.82 to 0.5139 N m-1. Furthermore, the nanoporous conductive polymer increases the specific electrochemical surface area after tissue penetration, resulting in an ultralow specific impedance of 893.13 Ω mm2 at 100 Hz. DSMNPs detect variation potential and action potential in real time and cation fluctuations in plants in response to environmental stimuli. After swelling, DSMNPs mechanically "lock" into biological tissues and prevent motion artifact by providing a stable interface. These results demonstrate the potential of DSMNPs for various applications in the field of plant physiology research and smart agriculture.

Impact of consensus guideline publication on the timing of elective pediatric umbilical hernia repair.

BACKGROUND: The American Academy of Pediatrics published consensus guidelines advising observation of asymptomatic umbilical hernias until age 4 or 5, given unnecessary risks of early intervention and substantial practice variation. Yet, the impact of guidelines on early repair (age <4) or if certain groups remain at risk for avoidable intervention is unclear. METHODS: This retrospective study used data from children's hospitals participating in the Pediatric Health Information System database. Children aged 17 years and younger who underwent umbilical hernia repair from July 2017 to August 2022 were eligible for inclusion. Children with recurrent hernias, an emergency, or urgent presentation were excluded. An interrupted time series using segmented multivariable logistic regression estimated the association of guideline publication in November 2019 with the odds of guideline-adherent repair (age ≥4) after adjusting for sociodemographic characteristics and hospital-level random effects. RESULTS: 16,544 children underwent repair, of which 3,115 (18.8%) were children <4 years old. After adjustment, guideline publication was associated with an immediate increase in guideline-adherent repairs (odds ratio = 1.25 95% confidence interval = 1.05-1.49). The interrupted time series found that each month after publication was associated with a 2% increase in the odds of guideline-adherent repair (odds ratio = 1.02, 95% confidence interval = 1.01-1.03). Children with public insurance were nearly 20% less likely to receive guideline-adherent repair than privately insured children (odds ratio = 0.82, 95% confidence interval = 0.74-0.91). Children in the Midwest had lower odds of guideline-adherent repair (Midwest versus Northeast: odds ratio = 0.45. 95% confidence interval = 0.24-0.84). CONCLUSION: Guideline publication was associated with greater odds of guideline-adherent repair, yet public insurance coverage and Midwest location remain significant predictors of early repair against recommendations.

Predictors and Variation in Steroid Injection Use for Carpal Tunnel Syndrome from a Multicenter Quality Collaborative.

BACKGROUND: Steroid injections are commonly used as first-line treatment for carpal tunnel syndrome (CTS); however, research has shown that their benefit is generally short-term and many patients go on to receive carpal tunnel release. The study purpose was to determine the variation in steroid injection use by hand surgeons. METHODS: We analyzed data from a 9-center hand surgery quality collaborative. Data from 1,586 patients (2,381 hands) were included if they underwent elective CTR at one of the sites. Mixed effects logistic regression models were used to examine the association of receipt of steroid injection and association of receipt of more than one steroid injection among patient-level covariates. RESULTS: Steroid injection use significantly varied by practice, ranging from 12-53% of patients. The odds of receiving a steroid injection were 1.4 times higher for females (p<0.01), 1.6 times higher for patients with chronic pain syndrome (p<0.01), 0.5 times lower for patients with moderate electromyography (EMG) and 0.4 times lower for patients with severe EMG classification (both p<0.01). Patients with high CTS-6 scores (p=0.02) and patients with moderate (p=0.04) or severe EMG (p=0.05) had lower odds of receiving multiple steroid injections. Complete symptomatic improvement after steroid injection was significantly reported by patients with high CTS-6 score (p=0.03) or patients with severe EMG classification (p=0.02). CONCLUSIONS: We found wide patient-level and practice-level variation in the use of steroid injections prior to undergoing CTR. These findings underscore the need for improved data and standard practice guidelines regarding which patients benefit from steroid injection.

Technology Roadmap for Flexible Sensors.

Humans rely increasingly on sensors to address grand challenges and to improve quality of life in the era of digitalization and big data. For ubiquitous sensing, flexible sensors are developed to overcome the limitations of conventional rigid counterparts. Despite rapid advancement in bench-side research over the last decade, the market adoption of flexible sensors remains limited. To ease and to expedite their deployment, here, we identify bottlenecks hindering the maturation of flexible sensors and propose promising solutions. We first analyze challenges in achieving satisfactory sensing performance for real-world applications and then summarize issues in compatible sensor-biology interfaces, followed by brief discussions on powering and connecting sensor networks. Issues en route to commercialization and for sustainable growth of the sector are also analyzed, highlighting environmental concerns and emphasizing nontechnical issues such as business, regulatory, and ethical considerations. Additionally, we look at future intelligent flexible sensors. In proposing a comprehensive roadmap, we hope to steer research efforts towards common goals and to guide coordinated development strategies from disparate communities. Through such collaborative efforts, scientific breakthroughs can be made sooner and capitalized for the betterment of humanity.

Compound Muscle Action Potential Amplitude as a Predictor of Functional and Patient-Reported Outcomes in Ulnar Neuropathy at the Elbow.

BACKGROUND: Ulnar neuropathy at the elbow (UNE) is a debilitating upper extremity condition that often leaves patients with residual symptoms even after surgical treatment. The role of electrodiagnostic studies in guiding the treatment of UNE is not well established, and conventional electrodiagnostic parameters may not reflect the severity of disease. Compound muscle action potential (CMAP) amplitude is a parameter that corresponds with axonal injury and motor symptoms and may more accurately predict the severity of neurologic injury. METHODS: This prospective multicenter study recruited 78 patients in the Surgery of the Ulnar Nerve project. Patients underwent electrodiagnostic testing and clinical assessment of motor and sensory function, and completed patient-reported outcome questionnaires, including the Michigan Hand Outcome Questionnaire; the Disabilities of the Arm, Shoulder and Hand questionnaire; and the Carpal Tunnel Questionnaire (CTQ). Correlations were measured among each of the electrodiagnostic parameters and outcomes and predictive models for each outcome were subsequently developed. RESULTS: Of all the electrodiagnostic parameters measured, only CMAP amplitude was predictive of scores on the Michigan Hand Outcome Questionnaire; Disabilities of the Arm, Shoulder and Hand questionnaire; CTQ function scale, and motor impairment in grip and pinch strength. None of the parameters were predictive of scores on the CTQ symptom scale or sensory impairments as measured with two-point discrimination or Semmes-Weinstein monofilament testing. CONCLUSIONS: CMAP amplitude, but not other conventional electrodiagnostic parameters, is predictive of functional outcomes in UNE. This electrodiagnostic measurement can alert the clinician to severe cases of UNE and inform surgical decision-making. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Electrodiagnostic Predictors of Outcomes After In Situ Decompression of the Ulnar Nerve.

PURPOSE: Patients with severe ulnar neuropathy at the elbow frequently experience suboptimal surgical outcomes. Clinical symptoms alone may not accurately represent the severity of underlying nerve injury, calling for objective assessment tools, such as electrodiagnostic studies. The goal of our study was to determine whether specific electrodiagnostic parameters can be used to predict the outcomes after in situ decompression of the ulnar nerve. METHODS: This prospective study enrolled consecutive patients aged ≥18 years diagnosed with ulnar neuropathy at the elbow. Patients completed a baseline battery of motor, sensory, functional, and electrodiagnostic tests before undergoing in situ decompression of the ulnar nerve. They were reassessed at 6 weeks, 3 months, 6 months, and 12 months after surgery. Forty-two patients completed at least 2 follow-up assessments and were included in the study. RESULTS: When controlling for other electrodiagnostic measurements and demographic factors, none of the electrodiagnostic parameters were predictive of outcomes at 12 months after surgery. Patients with decreased compound muscle action potential amplitudes demonstrated slower trends of recovery in grip strength, pinch strength, and overall scores on the Michigan Hand Outcomes Questionnaire as well as its function, work, and activities of daily living subscales, Disabilities of the Arm, Shoulder, and Hand questionnaire, and the Carpal Tunnel Questionnaire. Decreased motor nerve conduction velocity was predictive of slower recovery of 2-point discrimination and pinch strength. CONCLUSIONS: Compound muscle action potential amplitude, but not other conventional electrodiagnostic parameters, was predictive of functional outcomes after in situ decompression of the ulnar nerve. This parameter should play a role in determining the timing and prognosis of treatment for ulnar neuropathy at the elbow. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

Screen-based sedentary behaviors but not total sedentary time are associated with anxiety among college students.

Objective: The purpose of the study was to investigate the associations of device-measured total sedentary time and screen-based sedentary time with anxiety in college students. Methods: Three hundred and twenty-one college students (mean age = 19.72 ± 1.18, 55.8% females) were recruited from Shanghai, China. Total sedentary time was objectively measured using accelerometry, while screen-based sedentary time was self-reported. Anxiety symptom was evaluated using the Self-Rating Anxiety Scale. Linear regression modeling was used to assess the associations of total sedentary time and screen-based sedentary time with anxiety symptom. Results: Accelerometer-assessed total sedentary time was not associated with anxiety symptom. Prolonged sedentary time on TV and movie viewing (>2 h on weekdays) and social media using (>2 h on weekdays and weekend) were associated with a higher level of anxiety. However, time on video gaming and recreational reading was not associated with anxiety symptom. Conclusion: The findings indicated that screen-based sedentary behaviors but not total sedentary time were associated with anxiety symptom among college students. The associations of screen-based sedentary behaviors with anxiety symptom varied by the types of screen time.

Association Between Daytime vs Overnight Digit Replantation and Surgical Outcomes.

Importance: Recent evidence suggests that select delayed replantation may not adversely affect digit survival; however, whether surgical timing (overnight or daytime) is associated with digit replantation outcomes is unknown. Objective: To assess whether digit survival, complication rate, and duration of surgery are associated with time of replantation. Design, Setting, and Participants: This retrospective case series study included all replantations performed at a single tertiary referral academic center between January 1, 2000, and August 1, 2021. Data were analyzed between October 2, 2021, and January 1, 2022. Four daytime surgery intervals were selected based on literature review. Daytime replantations started within the intervals whereas overnight replantations began outside the intervals. For each case, the procedure difficulty score and the attending surgeon expertise score were calculated. Logistic and linear regressions adjusting for confounders including procedure difficulty score and expertise score were used to assess surgical timing and outcomes. Participants were adults (aged ≥18 years) undergoing digit replantations between January 2000 and August 2021 with at least 1-month follow-up. Replantation was defined as the reattachment of a completely amputated digit that necessitated anastomosis of both artery and vein. Exposures: Daytime or overnight digit replantation. Main Outcomes and Measures: Viable replanted digit at 1-month follow-up, number of complications, and duration of surgery. Results: A total of 98 patients (mean [SD] age, 39.5 [15.3] years; 136 [93%] men) and 147 digits met inclusion criteria. Overall success rate was 55%. Between 4 pm and 7 am, overnight replantations were associated with 0.4 fewer complications (ß, -0.4; 95% CI, -0.8 to -0.1) and 90.7 minutes shorter operative time (ß, -90.7; 95% CI, -173.6 to -7.7). A 1-point increase in surgeon expertise score was associated with 1.7 times increased odds of replantation success for all intervals (adjusted odds ratio, 1.7; 95% CI, 1.2 to 2.4; P = .002). There were no differences in digit survival by surgical time. Conclusions and Relevance: In this case series study of digit replantations, time of operation was not associated with replantation success. Overnight replantation was associated with fewer complications and shorter duration of surgery compared with daytime surgery. Results of this study suggest that overnight replantations may be performed with outcomes comparable to daytime replantations at a tertiary care academic center.

The combined impacts of selenium and phosphorus on the fate of arsenic in rice seedlings (Oryza sativa L.).

Although the single role of selenium (Se) or phosphorus (P) in regulating the As contamination of rice plants has been reported in some studies, the combined impacts of Se and P on the fate of As and the underlying mechanisms are poorly understood. To address this knowledge gap, the uptake, translocation, and biotransformation of As mediated by Se were investigated in rice (Oryza sativa L.) seedlings hydroponically cultured with P-normal and P-deficient conditions. The results showed Se addition stimulated the uptake of arsenite and arsenate by 15.6% and 30.7%, respectively in P-normal condition, and such effect was more profound in P-deficient condition with the value of 43.8% and 70.8%. However, regardless of Se addition, P-deficiency elevated the As uptake by 47.0%-92.1% for arsenate but had no obvious effects for arsenite. Accompanying with the As transfer factorShoot/Root reduced by 74.5%-80.2% and 71.1%-85.7%, Se addition decreased the shoot As content by 65.8%-69.7% and 59.6%-73.1%, respectively, in the arsenite- and arsenate-treated rice plants. Relative to the corresponding treatments of P-normal condition, P-deficiency reduced the As transfer factorShoot/Root by 38.9%-52.5% and thus decreasing the shoot As content by 35.2%-42.5% in the arsenite-treated plants; while the opposite impacts were observed in the arsenate-treated plants, in which the shoot As content was increased by 22.4%-83.7%. The analysis results of As species showed As(III) was dominant in both shoots (68.9%-75.1%) and roots (94.9%-97.2%), and neither Se addition nor P-deficiency had obvious impacts on the interconversion between As(III) and As(V). Our results demonstrate the regulating roles of Se in As accumulation mainly depend on P regimes and the specific rice tissues, but the effects of P-deficiency on the fate of As were influenced by the form of As added to the culture.

Uptake and translocation mechanisms of different forms of organic selenium in rice (Oryza sativa L.).

Selenium (Se) is an essential trace element for human and animal health, and toward an understanding of the uptake and translocation of Se in plants is important from the perspective of Se biofortification. In this study, we conducted hydroponic experiments to investigate the mechanisms of organic Se [selenomethionine (SeMet) and selenomethionine-oxide (SeOMet)] uptake, translocation, and the interactions between SeMet and SeOMet in rice. We also investigated differences in the dynamics of organic and inorganic Se uptake by rice roots. Concentration-dependent kinetic results revealed that SeMet uptake during a 1 h exposure was 3.19-16.0 times higher than that of three other Se chemical forms, with uptake capacity (Vmax ) values ordered as follows: SeMet>SeOMet>selenite>selenate. Furthermore, time-dependent kinetic analysis revealed that SeMet uptake by roots and content in shoots were initially clearly higher than those of SeOMet, although the differences gradually diminished with prolonged exposure time; while no significant difference was found in the transfer factor of Se from rice roots to shoots between SeMet and SeOMet. Root uptake of SeOMet was significantly inhibited by carbonyl cyanide 3-chlorophenylhydrazone (CCCP) (30.4%), AgNO3 (41.8%), and tetraethylammonium chloride (TEACl) (45.6%), indicating that SeOMet uptake is a metabolically active process, and that it could be mediated via aquaporins and K+ channels. Contrarily, SeMet uptake was insensitive to CCCP, although markedly inhibited by AgNO3 (93.1%), indicating that rice absorbs SeMet primarily via aquaporins. Furthermore, Se uptake and translocation in rice treated simultaneously with both SeMet and SeOMet were considerably lower than those in rice treated with SeMet treatment alone and notably lower than the theoretical quantity, indicating interactions between SeMet and SeOMet. Our findings provide important insights into the mechanisms underlying the uptake and translocation of organic Se within plants.

Accumulation of potentially toxic elements in Chinese tea (Camellia sinensis): Towards source apportionment and health risk assessment.

Tea (Camellia sinensis) is a popular beverage that is consumed globally. However, a better understanding of potentially toxic elements (PTEs) content in tea leaves and infusion is necessary to minimize risk on human health. Therefore, 249 tea samples (grown in different areas) covering six types of tea were collected in China to investigate the PTEs contents, identify their potential source and assess the health risk associated with drinking tea. PTE contents in tea leaves across six tea types were ND-0.900 (Cd), 0.005-2.133 (As), ND-5.679 (Pb), ND-13.86 (Cr), 1.601-22.93 (Ni), ND-2.048 (Se), 0.109-622.4 (F), 13.02-269.9 (Rb), 1.845-50.88 (Sr), and 2.796-53.23 (Ba) mg/kg. The result of tea infusion showed that 14.3 %-44.1 % (green tea), 14.5 %-46.7 % (black tea), 10.5 %-25.3 % (dark tea), 13.6 %-34.2 % (oolong tea), 16.9 %-40.7 % (yellow tea), and 19.9 %-35.1 % (white tea) of F were released. All tea types, except green tea, exhibited comparatively low leachability of Cd, As, Pb and Cr in tea infusion. The source apportionment revealed that PTEs in tea leaves mainly originated from soil parental materials, while industrial activities, fertilizer application, and manufacturing processes may contribute to exogenous Se, Cd, As, and Cr accumulation. Health risk assessment indicated that F in tea infusion dominated the health risk. Humans may be exposed to a higher health risk by drinking green tea compared to that of other tea types. Nevertheless, the long-term tea consumption is less likely to contribute to pronounced non-carcinogenic and carcinogenic risks. This study confirmed that tea consumption is an important and direct pathway of PTEs uptake in humans. The health risk associated with drinking tea should be of concern.