The transcription factor MYB110 regulates plant height, lodging resistance, and grain yield in rice.

The high-yielding Green Revolution varieties of cereal crops are characterized by a semidwarf architecture and lodging resistance. Plant height is tightly regulated by the availability of phosphate (Pi), yet the underlying mechanism remains obscure. Here, we report that rice (Oryza sativa) R2R3-type Myeloblastosis (MYB) transcription factor MYB110 is a Pi-dependent negative regulator of plant height. MYB110 is a direct target of PHOSPHATE STARVATION RESPONSE 2 (OsPHR2) and regulates OsPHR2-mediated inhibition of rice height. Inactivation of MYB110 increased culm diameter and bending resistance, leading to enhanced lodging resistance despite increased plant height. Strikingly, the grain yield of myb110 mutants was elevated under both high- and low-Pi regimes. Two divergent haplotypes based on single nucleotide polymorphisms in the putative promoter of MYB110 corresponded with its transcript levels and plant height in response to Pi availability. Thus, fine-tuning MYB110 expression may be a potent strategy for further increasing the yield of Green Revolution cereal crop varieties.

Efficient Alkene Hydroformylation by Co-C Symmetry-Breaking Sites.

Alkene hydroformylation is one of the largest industrial reactions on an industrial scale; however, the development of nonnoble heterogeneous catalysts is usually limited by their low activities and stabilities. Herein, we constructed a 1% Co2C/SiO2 catalyst featuring Co-Cvacancy-Co-C symmetry-breaking sites, which generated a polar surface exhibiting a moderate charge density gradient at the localized Co atoms. Comparatively, this catalyst exhibited notable enhancements in the adsorption and activation of the reactants, as well as in the polarity between intermediates. Significantly, the spatial distance between the adsorption sites of intermediates was reduced, thereby effectively decreasing the energy barrier of reaction processes. As the density of the symmetry-breaking sites increased, the turnover number for propene hydroformylation soared to 18 363, exceeding the activity of heterogeneous Co-based catalysts reported thus far by 1 or 2 orders of magnitude, and the catalyst exhibited high stability during the reaction. This study provides a methodology for constructing atomically active sites, which holds great potential for the design and development of highly efficient catalysts.

Converting Plastic Wastes to Naphtha for Closing the Plastic Loop.

To solve the serious environmental problem and huge resource waste of plastic pollution, we report a tandem catalytic conversion of low-density polyethylene (LDPE) into naphtha, the key feedstock for renewable plastic production. Using ß zeolite and silicalite-1-encapsulated Pt nanoparticles (Pt@S-1), a naphtha yield of 89.5% is obtained with 96.8% selectivity of C5-C9 hydrocarbons at 250 °C. The acid sites crack long-chain LDPE into olefin intermediates, which diffuse within the channels of Pt@S-1 to encounter Pt nanoparticles. The hydrogenation over confined metal matches cracking steps by selectively shipping the olefins with right size, and the rapid diffusion boosts the formation of narrow-distributed alkanes. A conceptual upgrading indicates it is suitable for closing the plastic loop, with a significant energy saving of 15% and 30% reduced greenhouse gas emissions.

Improving rice eating and cooking quality by enhancing endogenous expression of a nitrogen-dependent floral regulator.

Improving rice eating and cooking quality (ECQ) is one of the primary tasks in rice production to meet the rising demands of consumers. However, improving grain ECQ without compromising yield faces a great challenge under varied nitrogen (N) supplies. Here, we report the approach to upgrade rice ECQ by native promoter-controlled high expression of a key N-dependent floral and circadian clock regulator Nhd1. The amplification of endogenous Nhd1 abundance alters rice heading date but does not affect the entire length of growth duration, N use efficiency and grain yield under both low and sufficient N conditions. Enhanced expression of Nhd1 reduces amylose content, pasting temperature and protein content while increasing gel consistence in grains. Metabolome and transcriptome analyses revealed that increased expression of Nhd1 mainly regulates the metabolism of carbohydrates and amino acids in the grain filling stage. Moreover, expression level of Nhd1 shows a positive relationship with grain ECQ in some local main cultivars. Thus, intensifying endogenous abundance of Nhd1 is a promising strategy to upgrade grain ECQ in rice production.

The rice transcription factor Nhd1 regulates root growth and nitrogen uptake by activating nitrogen transporters.

Plants adjust root architecture and nitrogen (N) transporter activity to meet the variable N demand, but their integrated regulatory mechanism remains unclear. We have previously reported that a floral factor in rice (Oryza sativa), N-mediated heading date-1 (Nhd1), regulates flowering time. Here, we show that Nhd1 can directly activate the transcription of the high-affinity ammonium (NH4+) transporter 1;3 (OsAMT1;3) and the dual affinity nitrate (NO3-) transporter 2.4 (OsNRT2.4). Knockout of Nhd1 inhibited root growth in the presence of NO3- or a low concentration of NH4+. Compared to the wild-type (WT), nhd1 and osamt1;3 mutants showed a similar decrease in root growth and N uptake under low NH4+ supply, while nhd1 and osnrt2.4 mutants showed comparable root inhibition and altered NO3- translocation in shoots. The defects of nhd1 mutants in NH4+ uptake and root growth response to various N supplies were restored by overexpression of OsAMT1;3 or OsNRT2.4. However, when grown in a paddy field with low N availability, nhd1 mutants accumulated more N and achieved a higher N uptake efficiency (NUpE) due to the delayed flowering time and prolonged growth period. Our findings reveal a molecular mechanism underlying the growth duration-dependent NUpE.

Rice circadian clock regulator Nhd1 controls the expression of the sucrose transporter gene OsSUT1 and impacts carbon-nitrogen balance.

Interdependent metabolic and transport processes of carbon (C) and nitrogen (N) regulate plant growth and development, while the regulatory pathways remain poorly defined. We previously reported that rice circadian clock N-mediated heading date-1 (Nhd1) regulates growth duration-dependent N use efficiency. Here, we report that knockout of Nhd1 in rice reduced the rate of photosynthesis and the sucrose ratio of sheaths to blades, but increased the total C to N ratio and free amino acids. Leaf RNA-seq analysis indicated that mutation of Nhd1 dramatically altered expression of the genes linked to starch and sucrose metabolism, circadian rhythm, and amino acid metabolic pathways. We identified that Nhd1 can directly activate the transcriptional expression of sucrose transporter-1 (OsSUT1). Knockout of Nhd1 suppressed OsSUT1 expression, and both nhd1 and ossut1 mutants showed similar shorter height, and lower shoot biomass and sucrose concentration in comparison with the wild type, while overexpression of OsSUT1 can restore the defective sucrose transport and partially ameliorate the reduced growth of nhd1 mutants. The Nhd1-binding site of the OsSUT1 promoter is conserved in all known rice genomes. The positively related variation of Nhd1 and OsSUT1 expression among randomly selected indica and japonica varieties suggests a common regulatory module of Nhd1-OsSUT1-mediated C and N balance in rice.

Abnormal uterine bleeding patterns determined through menstrual tracking among participants in the Apple Women's Health Study.

BACKGROUND: Use of menstrual tracking data to understand abnormal bleeding patterns has been limited because of lack of incorporation of key demographic and health characteristics and confirmation of menstrual tracking accuracy. OBJECTIVE: This study aimed to identify abnormal uterine bleeding patterns and their prevalence and confirm existing and expected associations between abnormal uterine bleeding patterns, demographics, and medical conditions. STUDY DESIGN: Apple Women's Health Study participants from November 2019 through July 2021 who contributed menstrual tracking data and did not report pregnancy, lactation, use of hormones, or menopause were included in the analysis. Four abnormal uterine bleeding patterns were evaluated: irregular menses, infrequent menses, prolonged menses, and irregular intermenstrual bleeding (spotting). Monthly tracking confirmation using survey responses was used to exclude inaccurate or incomplete digital records. We investigated the prevalence of abnormal uterine bleeding stratified by demographic characteristics and used logistic regression to evaluate the relationship of abnormal uterine bleeding to a number of self-reported medical conditions. RESULTS: There were 18,875 participants who met inclusion criteria, with a mean age of 33 (standard deviation, 8.2) years, mean body mass index of 29.3 (standard deviation, 8.0), and with 68.9% (95% confidence interval, 68.2-69.5) identifying as White, non-Hispanic. Abnormal uterine bleeding was found in 16.4% of participants (n=3103; 95% confidence interval, 15.9-17.0) after accurate tracking was confirmed; 2.9% had irregular menses (95% confidence interval, 2.7-3.1), 8.4% had infrequent menses (95% confidence interval, 8.0-8.8), 2.3% had prolonged menses (95% confidence interval, 2.1-2.5), and 6.1% had spotting (95% confidence interval, 5.7-6.4). Black participants had 33% higher prevalence (prevalence ratio, 1.33; 95% confidence interval, 1.09-1.61) of infrequent menses compared with White, non-Hispanic participants after controlling for age and body mass index. The prevalence of infrequent menses was increased in class 1, 2, and 3 obesity (class 1: body mass index, 30-34.9; prevalence ratio, 1.31; 95% confidence interval, 1.13-1.52; class 2: body mass index, 35-39.9; prevalence ratio, 1.25; 95% confidence interval, 1.05-1.49; class 3: body mass index, >40; prevalence ratio, 1.51; 95% confidence interval, 1.21-1.88) after controlling for age and race/ethnicity. Those with class 3 obesity had 18% higher prevalence of abnormal uterine bleeding compared with healthy-weight participants (prevalence ratio, 1.18; 95% confidence interval, 1.02-1.38). Participants with polycystic ovary syndrome had 19% higher prevalence of abnormal uterine bleeding compared with participants without this condition (prevalence ratio, 1.19; 95% confidence interval, 1.08-1.31). Participants with hyperthyroidism (prevalence ratio, 1.34; 95% confidence interval, 1.13-1.59) and hypothyroidism (prevalence ratio, 1.17; 95% confidence interval, 1.05-1.31) had a higher prevalence of abnormal uterine bleeding, as did those reporting endometriosis (prevalence ratio, 1.28; 95% confidence interval, 1.12-1.45), cervical dysplasia (prevalence ratio, 1.20; 95% confidence interval, 1.03-1.39), and fibroids (prevalence ratio, 1.14; 95% confidence interval, 1.00-1.30). CONCLUSION: In this cohort, abnormal uterine bleeding was present in 16.4% of those with confirmed menstrual tracking. Black or obese participants had increased prevalence of abnormal uterine bleeding. Participants reporting conditions such as polycystic ovary syndrome, thyroid disease, endometriosis, and cervical dysplasia had a higher prevalence of abnormal uterine bleeding.

I know my teammates: the role of Group Member Familiarity in Computer-Supported and face-to-face collaborative learning.

Considering the importance of group member familiarity in collaborative learning in classroom learning environments, this study examined the impact of group member familiarity on CSCL (computer-supported collaborative learning) in a networked setting. Also, the differences between CSCL in the online environments and FtF (face-to-face) collaborative learning were also compared. An analysis using structural equation modeling revealed that group member familiarity increased teamwork satisfaction, which in turn increased student engagement and perceived knowledge construction. A multi-group analysis revealed that while FtF collaborative learning exhibits higher levels of group member familiarity, teamwork satisfaction, student engagement, and perceived knowledge construction, the mediating effect of teamwork satisfaction was more pronounced in online settings. The study findings provided insights for teachers to improve collaborative learning experiences and adapt different teaching strategies.

Nitrogen removal characteristics of a novel heterotrophic nitrification and aerobic denitrification bacteria, Alcaligenes faecalis strain WT14.

Alcaligenes faecalis strain WT14 is heterotrophic nitrification and aerobic denitrification bacterium, newly isolated from a constructed wetland, and its feasibility in nitrogen removal was investigated. The result showed sodium citrate was more readily utilized by WT14 as a carbon source. The response surface methodology model revealed the highest total nitrogen removal by WT14 occurred at 20.3 °C, 113.5 r·min-1, C/N 10.8, and pH 8.4. Under adapted environmental conditions, up to 55.9 mg·L-1·h-1 of ammonium nitrogen (NH4+-N) was removed by WT14, and its NH4+-N tolerance ability reached 2000 mg·L-1. In addition to the reported high NH4+-resistance of Alcaligenes faecalis, WT14 multiplied fast and had strong nitrate or nitrite removal capacity when high strength nitrate or nitrite was provided as the single nitrogen source; which differed from other Alcaligenes faecalis species. These results show WT14 is a novel strain of Alcaligenes faecalis and its nitrogen removal pathway will be carried out in the further study.

Nitrogen removal performance and needed area estimation of surface-flow constructed wetlands using a probabilistic approach.

Pollutant concentrations in influents into constructed wetlands (CWs) are highly fluctuating and may vary over several orders of magnitude, leading to large uncertainties in removal performance assessment when using pollutant concentrations in the influent and effluent directly. Incorporating a probabilistic approach into removal performance assessment and needed area estimation of CWs could advantage decision making regarding wastewater treatment and engineering applications. A series of three-stage surface-flow CWs (SFCWs) were constructed for treating ammonium-rich swine wastewater. The surface removal rate and removal efficiency of ammonium nitrogen in the SFCWs using the probabilistic approach were 0.27-3.23 g m-2 d-1 and 43.0-99.9% (95% confidence interval (CI)), which were consistent with the deterministic approach (95% CI: 0.24-3.18 g m-2 d-1 and 70.4-99.9%). The needed SFCW area was estimated as 6.6 (95% CI: 1.4-17.8) to 29.7 (95% CI: 6.4-80.1) m2 for required removal efficiency from 40% to 90% for 0.18 m3 d-1 swine wastewater with different strengthens. For specific removal efficiency of 90%, the needed CW areas was 13.9 (95%CI: 4.9-42.7), 25.1 (95%CI: 5.9-66.0), 33.5 (95%CI: 13.5-87.1), and 40.8 (95%CI: 16.2-89.4) m2 for influent ammonium loading rate of 0.18-2.7, 2.7-14.4, 14.4-36, and 36-60 g d-1, respectively. The first-order removal constant of ammonium nitrogen decreased logarithmically with increasing influent and effluent concentration/loading rate in the SFCW units (p < 0.001), which was responsible for the needed SFCW areas covering a wide range. The reliability analysis confirmed the results from the probabilistic approach were appropriate. The present study shed new lights on the performance evaluation and design of CWs for treating wastewater with highly-fluctuating concentrations using a probabilistic approach.

Nitrogen removal in Myriophyllum aquaticum wetland microcosms for swine wastewater treatment: 15 N-labelled nitrogen mass balance analysis.

BACKGROUND: Ecological treatments are effective for treating agricultural wastewater. In this study, wetland microcosms vegetated with Myriophyllum aquaticum were designed for nitrogen (N) removal from two strengths of swine wastewater, and 15 N-labelled ammonium (NH4+ -N) was added to evaluate the dominant NH4+ -N removal pathway. RESULTS: The results showed that 98.8% of NH4+ -N and 88.3% of TN (TN: 248.6 mg L-1 ) were removed from low-strength swine wastewater (SW1) after an incubation of 21 days, with corresponding values for high-strength swine wastewater (SW2) being 99.2% of NH4+ -N and 87.8% of TN (TN: 494.9 mg L-1 ). Plant uptake and soil adsorption respectively accounted for 24.0% and 15.6% of the added 15 N. Meanwhile, above-ground tissues of M. aquaticum had significantly higher biomass and TN content than below-ground (P < 0.05). 15 N mass balance analysis indicated that gas losses contributed 52.0% to the added 15 N, but the N2 O flux constituted only 7.5% of total gas losses. The dynamics of NO3- -N and N2 O flux revealed that strong nitrification and denitrification occurred in M. aquaticum microcosms, which was a dominant N removal pathway. CONCLUSION: These findings demonstrated that M. aquaticum could feasibly be used to construct wetlands for high N-loaded animal wastewater treatment. © 2016 Society of Chemical Industry.

Bayesian neural adjustment of inhibitory control predicts emergence of problem stimulant use.

Bayesian ideal observer models quantify individuals' context- and experience-dependent beliefs and expectations about their environment, which provides a powerful approach (i) to link basic behavioural mechanisms to neural processing; and (ii) to generate clinical predictors for patient populations. Here, we focus on (ii) and determine whether individual differences in the neural representation of the need to stop in an inhibitory task can predict the development of problem use (i.e. abuse or dependence) in individuals experimenting with stimulants. One hundred and fifty-seven non-dependent occasional stimulant users, aged 18-24, completed a stop-signal task while undergoing functional magnetic resonance imaging. These individuals were prospectively followed for 3 years and evaluated for stimulant use and abuse/dependence symptoms. At follow-up, 38 occasional stimulant users met criteria for a stimulant use disorder (problem stimulant users), while 50 had discontinued use (desisted stimulant users). We found that those individuals who showed greater neural responses associated with Bayesian prediction errors, i.e. the difference between actual and expected need to stop on a given trial, in right medial prefrontal cortex/anterior cingulate cortex, caudate, anterior insula, and thalamus were more likely to exhibit problem use 3 years later. Importantly, these computationally based neural predictors outperformed clinical measures and non-model based neural variables in predicting clinical status. In conclusion, young adults who show exaggerated brain processing underlying whether to 'stop' or to 'go' are more likely to develop stimulant abuse. Thus, Bayesian cognitive models provide both a computational explanation and potential predictive biomarkers of belief processing deficits in individuals at risk for stimulant addiction.

Nitrogen removal and mass balance in newly-formed Myriophyllum aquaticum mesocosm during a single 28-day incubation with swine wastewater treatment.

The aim of this research was to assess the applicability of Myriophyllum (M.) aquaticum for swine wastewater treatment. Nitrogen (N) removal processes were investigated in M. aquaticum mesocosms with swine wastewater (SW), 50% diluted swine wastewater (50% SW), and two strengths of synthetic wastewater, 200 mg [Formula: see text] L(-1) (200 [Formula: see text] ) and 400 mg [Formula: see text] L(-1) (400 [Formula: see text] ). During a 28-day incubation period, the average [Formula: see text] and TN removal rates were 99.8% and 94.2% for 50% SW and 99.8% and 93.8% for SW, which were greater than 86.5% and 83.7% for 200 [Formula: see text] , and 73.7% and 74.1% for 400 [Formula: see text] , respectively. A maximum areal total nitrogen (TN) removal rate of 157.8 mg N m(-2) d(-1) was found in M. aquaticum mesocosms with SW. During the incubation period, the observed dynamics of [Formula: see text] concentrations in water and gene copy numbers of ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB), nirK and nirS in soil unraveled strong nitrification and denitrification processes occurring in M. aquaticum mesocosms with swine wastewater. The N mass balance analysis indicated that plant uptake and soil N accumulation accounted for 17.9-42.2% and 18.0-43.8% of the initial TN load, respectively. The coupled nitrification and denitrification process was calculated to account for, on average, 36.8% and 62.8% of TN removal for 50% SW and SW, respectively. These findings demonstrated that the N uptake by M. aquaticum contributed to a considerable proportion of N removal. In particular, the activities of ammonia-oxidizing and denitrification microbes responsible for nitrification and denitrification processes in M. aquaticum mesocosm accelerated [Formula: see text] and TN removal from swine wastewater.

Dapagliflozin-induced abnormal uterine bleeding in a patient with dilated cardiomyopathy and chronic heart failure: a case report.

Sodium-glucose cotransporter-2 (SGLT2) inhibitors are extensively used in the management of heart failure because of their cardiovascular benefits. Adverse drug reactions associated with dapagliflozin include diabetic ketoacidosis, fungal infections, and increased blood glucose concentrations. However, abnormal uterine bleeding is not a known side effect of dapagliflozin. We report a 75-year-old Chinese woman with dilated cardiomyopathy and chronic heart failure who experienced abnormal uterine bleeding while taking dapagliflozin. Notably, cessation of dapagliflozin administration resulted in the disappearance of uterine bleeding. These findings suggest that dapagliflozin possesses additional potential mechanisms, but these mechanisms require further investigation. Furthermore, healthcare professionals should remain vigilant regarding the occurrence of uterine bleeding when prescribing dapagliflozin.

Effects of multi-plant harvesting on nitrogen removal and recovery in constructed wetlands.

The harvesting of plants is considered an effective method for nutrient recovery in constructed wetlands (CWs). However, excessive plant harvesting can lead to a decrease in plant biomass. It remains unclear what harvesting frequency can optimize plant nutrient uptake and pollutant removal. In this study, CWs planted with Myriophyllum aquaticum were constructed, and three different frequencies of plant harvesting (high: 45 days/time; low: 90 days/time; none: CK) were set to investigate nitrogen removal and its influencing mechanism, as well as the capacity for plant nutrient recovery. The results showed that the average removal efficiencies of ammonia nitrogen (NH4+-N) at 45 days/time, 90 days/time, and CK were 90.3%, 90.8%, and 88.3% respectively, while the corresponding total nitrogen (TN) were 61.2%, 67.4%, and 67.4%. Dissolved oxygen (DO) concentration and water temperature were identified as the main environmental factors affecting nitrogen removal efficiency. Low harvest frequency (90 days/time) increased DO concentration and NH4+-N removal efficiency without impacting TN removal. Additionally, TN recovery from plants under high and low harvest was found to be approximately 9.21-9.32 times higher than that from no harvest conditions. The above studies indicated that a harvest frequency of every 90 days was one appropriate option for M. aquaticum, which not only increased NH4+-N removal efficiencies but also facilitated more efficient nitrogen recovery from the wetland system.

Mechanisms of total phosphorus removal and reduction of ß-lactam antibiotic resistance genes by exogenous fungal combination activated sludge.

This study utilized Trichoderma and activated sludge to construct combined activated sludge (TAS). The metagenomic approach was employed to examine the shifts in microbial community structure and function of TAS under amoxicillin stress and investigate the mechanism underlying the reduction of ß-lactam antibiotic resistance genes (ß-ARGs). The findings demonstrated that the elevated aundance of glpa, glpd, ugpq, glpq, and glpb were primarily responsible for the reduction in total phosphorus (TP) removal by TAS. The increased abundance of Proteobacteria and Verrucomicrobia led to enhanced expression of ugpb, phnd, and phne, thereby improving the TP removal of TAS. Furthermore, antibiotic inactivation has gradually become the primary antibiotic resistance mechanism in TAS. Specifically, an increase in the abundance of OXA-309 in TAS will decrease the probability of amoxicillin accumulation in TAS. A decrease in ß-ARGs diversity confirmed this. This study presents a novel approach to reducing antibiotic and ARG accumulation in sludge.

PROTAC Prodrug-Integrated Nanosensitizer for Potentiating Radiation Therapy of Cancer.

Radiation therapy (RT) is one of the primary options for clinical cancer therapy, in particular advanced head and neck squamous cell carcinoma (HNSCC). Herein, the crucial role of bromodomain-containing protein 4 (BRD4)-RAD51 associated protein 1 (RAD51AP1) axis in sensitizing RT of HNSCC is revealed. A versatile nanosensitizer (RPB7H) is thus innovatively engineered by integrating a PROteolysis TArgeting Chimeras (PROTAC) prodrug (BPA771) and hafnium dioxide (HfO2) nanoparticles to downregulate BRD4-RAD51AP1 pathway and sensitize HNSCC tumor to RT. Upon intravenous administration, the RPB7H nanoparticles selectively accumulate at the tumor tissue and internalize into tumor cells by recognizing neuropilin-1 overexpressed in the tumor mass. HfO2 nanoparticles enhance RT effectiveness by amplifying X-ray deposition, intensifying DNA damage, and boosting oxidative stress. Meanwhile, BPA771 can be activated by RT-induced H2O2 secretion to degrade BRD4 and inactivate RAD51AP1, thus impeding RT-induced DNA damage repair. This versatile nanosensitizer, combined with X-ray irradiation, effectively regresses HNSCC tumor growth in a mouse model. The findings introduce a PROTAC prodrug-based radiosensitization strategy by targeting the BRD4-RAD51AP1 axis, may offer a promising avenue to augment RT and more effective HNSCC therapy.

Aerobic Oxidative Carboxylation of Styrene Over Cobalt Catalysts: Integrated CO2 Capture and Conversion.

The direct synthesis of cyclic carbonates through oxidative carboxylation of alkenes using CO2 and O2 offers a sustainable and carbon-neutral method for CO2 utilization, which is, however, still a largely unexplored field. Here we develop a single-atom catalyst (SAC) Co-N/O-C as the earth-abundant metal catalyst for the oxidative carboxylation of styrene with CO2 and O2. Remarkably, even using the flue gas as an impure CO2 and O2 source, desired cyclic carbonate could be obtained with moderate productivity, which shows the potential for integrated CO2 capture and conversion, leveraging the high CO2 adsorption capacity of Co-N/O-C. In addition, the catalyst can be reused five times without an obvious decline in activity. Detailed characterizations and theoretical calculations elucidate the crucial role of single Co atoms in activating O2 and CO2, as well as controlling selectivity.

Trends in sensor-based health metrics during and after pregnancy: descriptive data from the apple women's health study.

Background: While it is known that vital signs and behaviors change during pregnancy, there is limited data on timing and scale of changes for sensor-derived health metrics across pregnancy and postpartum. Wearable technology provides an opportunity to understand physiologic and behavioral changes across pregnancy with greater detail, more frequent measurements, and improved accuracy. The aim of this study is to describe changes in physiologic and behavioral sensor-based health metrics during pregnancy and postpartum in the Apple Women's Health Study (AWHS) and their relationship to demographic factors. Methods: The Apple Women's Health Study is a digital, longitudinal, observational study that includes U.S. residents with an iPhone and Apple Watch. We evaluated changes from pre-pregnancy through delivery and postpartum for sensor-derived health metrics. Minimum required data samples per day, week and overall were data element specific, and included 12 weeks prior to pregnancy start, and 12 weeks postpartum for pregnancies lasting between 24 and 43 weeks. Findings: A total of 757 pregnancies from 733 participants were included. Resting heart rate (RHR) increased across pregnancy, peaking in the third trimester (pre-pregnancy median RHR 65.0 beats per minute [BPM], interquartile range [IQR] 60.0-70.2 B.M. third trimester median RHR 75.5 B.M. IQR 69.0-82.0 B.M., with a decrease prior to delivery and nadir postpartum (postpartum median RHR 62.0 B.M. IQR 57.0-66.0 B.M.. Heart rate variability (HRV) decreased from pre-pregnancy (39.9 milliseconds, IQR 32.6-48.3 milliseconds), reaching a nadir in the third trimester (29.9 milliseconds, IQR 25.2-36.4 milliseconds), before rebounding in the last weeks of pregnancy. Measures of activity, such as exercise minutes, stand minutes, step count and Cardio Fitness were all decreased in each trimester compared to pre-pregnancy, with their nadirs postpartum. Total sleep duration increased slightly in early pregnancy (pre-pregnancy 7.2 hours, IQR 6.7-7.7 hours; 1st trimester 7.4 hours, IQR 6.8-7.9 hours), with the lowest sleep duration postpartum (6.2 hours, IQR 5.4-6.8 hours). Interpretation: Resting heart rate increased during pregnancy, with a decrease prior to delivery, while heart rate variability decreased across pregnancy, with an upward trend before delivery. Behavioral metrics, such as exercise and sleep, showed decreasing trends during and after pregnancy. These data provide a foundation for understanding normal pregnancy physiology and can facilitate hypothesis generation related to physiology, behavior, pregnancy outcomes and disease.