A low-cost approach to upskilling tutors in frontline health care worker production value chain.

Nigeria, like many countries, struggles with a shortage of healthcare professionals including frontline healthcare providers at the primary healthcare (PHC) level. While the country is pitched towards producing more healthcare professionals, the existing infrastructure to produce them is inadequate. Producing healthcare professional with the required skills to deliver quality services is impeded by several factors including the use of outdated curricula for their training, low application of technology in teaching, and weak tutor capacity that is worsened by the paucity and high cost of opportunities for tutor continuing professional development. To address these issues, the Health Workforce Management Activity (HWM), an initiative of the United States Agency for International Development (USAID), in 2023 designed and implemented a low-cost programme called TutorConnect that offered low-cost continuing professional development to tutors. TutorConnect is a Zoom-based monthly training programme that is facilitated by subject matter experts. The programme offered topics spanning effective learning, enhanced instructional design, and improved student engagement in the 14 months of its operation with over 700 tutors from more than 10 states in Nigeria that benefited from it. Utilising WhatsApp for additional support and peer-to-peer learning was crucial to providing more hands-on support, and institution-specific solutions. This low-cost approach to build competencies enabled access to continuing professional development by tutors, limiting effects of location and finances as barriers to continuing professional development. Developing the teaching capacity of tutors is pivotal to enhancing the quality of frontline healthcare worker training.

Kerala's progress towards universal health coverage: the road travelled and beyond.

BACKGROUND: Kerala has initiated many Universal Health Coverage (UHC) reforms in the last decade. The Aardram Mission launched in 2017 stands out owing to its scope, objectives, and commitments for strengthening Primary Health Care (PHC) in the State. The current study proposes to explore access and financial protection through the lens of equity in Kerala especially in the context of major UHC reforms carried out during the last decade. This paper will also highlight the key lessons from Kerala's approach towards UHC and health systems strengthening through a political economy approach. METHODS: Data from the Kerala state sample of 75th Round (2017-18) National Sample Survey is used for this study. Comparison is also drawn from the 71st Round Sample Survey, 2014, to measure the state's progress in terms of access and financial protection. Logistic regression was used for the calculation. The findings were further explored through a political economy approach. RESULTS: The share of public facilities for outpatient care is 47.5%, which is a significant increase from 34.0% (in 2014) in the state. The share of public sector for out-patient care has increased for the lower socio-economic population in the state. The share of public sector for in-patient care has also increased to 37.3% in 2017-18 from 33.9% in 2014, but not to the extent as the increase shown in outpatient care. The average out-of-pocket-expenditure during hospitalization has increased more in private facilities as compared to public for both outpatient care and hospitalization. CONCLUSIONS: Overall increase in the share of public facilities for both outpatient care and hospitalization is indicative of the enhanced trust among the people at large of the public healthcare delivery system in Kerala, post the launch of UHC reforms in the State. The insurance linked UHC reforms would be insufficient for the State to progress further towards UHC. Kerala with a long and successful history in 'public provisioning' should focus more on strengthening PHC through Aardram Mission in its journey towards pursuit of UHC.

Exploring the relationship between vitamin D and hepatic carcinoma in individuals diagnosed with hepatitis B virus infection.

OBJECTIVE: The primary objective of this study is to examine the distribution and prognostic implications of serum vitamin D levels among individuals diagnosed with primary hepatic carcinoma (PHC) attributable to hepatitis B virus (HBV) infection. METHODS: A total of 345 patients diagnosed with HBV infection were enrolled in our hospital between August 2014 and October 2020. Among these, 144 individuals were diagnosed with chronic hepatitis B (CHB), 66 individuals were diagnosed with HBV-related hepatic cirrhosis (HBV cirrhosis), and 135 individuals were diagnosed with HBV-related PHC (HBV-PHC). Peripheral serum levels of vitamin D were measured. Patients with cirrhosis underwent examination using the Child-Pugh grading system, and the mortality rates at 1-year and 3-year intervals for patients with HBV-PHC were analyzed. RESULTS: Vitamin D levels in peripheral serum in the CHB group, HBV cirrhosis group, and HBV-PHC group exhibited varying degrees of reduction compared to healthy individuals. Significant differences were observed between the three groups (F = 4.02, P = 0.019). No significant difference was observed in vitamin D levels between different Child-Pugh grades within the HBV cirrhosis group (F = 0.89, P = 0.417). However, significant differences were observed in vitamin D levels between different Child-Pugh grades within the HBV-PHC group (F = 4.84, P = 0.009). There was no significant difference in 1-year and 3-year mortality rates between patients diagnosed with HBV-PHC and with varying vitamin D levels (P > 0.05). CONCLUSIONS: Vitamin D levels decreased to varying degrees in patients diagnosed with CHB, HBV cirrhosis, and PHC. This decrease was well correlated with disease progression (HBV-PHC group < HBV cirrhosis group < CHB group). In cases where hepatic function was comparable, there was no discernible correlation between serum vitamin D level and mortality rates from PHC.

Primary Healthcare Marketing: A Bibliometric Study and Research Agenda.

The evolution of our lives has forced changes to the healthcare system and consequently established healthcare marketing as an essential element of health services, including primary health care (PHC). This article aims to analyze the size, structure, and dynamics of research on primary healthcare marketing to identify the main topics and research trends in this area. The authors conducted a bibliographic analysis based on the methods of performance analysis and scientific mapping. The bibliographical analysis covered 1981 publications selected from the Scopus database and was carried out with the use of the MS Excel and VOSviewer applications. The results were supplemented with an in-depth analysis of 34 publications selected based on bibliographic coupling analysis to determine key research trends and results, which increased the understanding of the research area. The conducted research proves that the issue of marketing in primary health care is rarely addressed by researchers, which translates into very limited research results and little impact on the decision-making process in this area. This research field requires much greater commitment, especially in the areas indicated in the future research agenda recommendations.

Primary health care in Nigeria: best practices and quality of care in Nigeria.

INTRODUCTION: The significance of Primary Healthcare Centers (PHCCs) in fostering health equity and enhancing health outcomes cannot be overstated, especially in low and middle-income countries. This paper's primary area of interest is to create evidence and innovation for PHCs, with a particular emphasis on underserved groups. Thus, the study aimed to investigate the state of primary health care in Nigeria, with a particular emphasis on best practices, challenges to best practices, and quality of care. METHODOLOGY: A cross-sectional quantitative study was conducted to collect secondary data from 29 primary healthcare facilities. The data was collected using staff and facility activity indicators over a year (2022). Descriptive statistics and chi-square tests were used to analyze the collected data. RESULT: Our study data showed that all of the PHCCs have service rosters that can be utilized for follow-up with patients. About 85 (84.1%) respondents have reported that deliveries were taken by the reporting midwife, and 55 (54.5%) respondents indicated that their facilities provided on-the-job training to their staff. This is considered as the best practice in the facility. However, the majority of the PHCCs (71.3%) lacked assessment teams, which was found to have a negative impact on the quality of healthcare provided at these facilities (p < 0.05). CONCLUSION: Our study underscores the pressing need for primary healthcare services in Nigeria. Government authorities and healthcare providers must take action to overcome the challenges of limited capacity, service delivery, and quality of care. By adopting effective strategies and ensuring access to primary healthcare, citizens' health outcomes can be greatly enhanced. Thus, it is essential to revamp and optimize healthcare facilities to establish an efficient healthcare system that caters to the needs of all citizens.

Ensemble learning enhances the precision of preliminary detection of primary hepatocellular carcinoma based on serological and demographic indices.

Primary hepatocellular carcinoma (PHC) is associated with high rates of morbidity and malignancy in China and throughout the world. In clinical practice, a combination of ultrasound and alpha-fetoprotein (AFP) measurement is frequently employed for initial screening. However, the accuracy of this approach often falls short of the desired standard. Consequently, this study aimed to investigate the enhancement of precision of preliminary detection of PHC by ensemble learning techniques. To achieve this, 712 patients with PHC and 1887 healthy controls were enrolled for the assessment of four ensemble learning methods, namely, Random Forest (RF), LightGBM, Xgboost, and Catboost. A total of eleven characteristics, comprising nine serological indices and two demographic indices, were selected from the participants for use in detecting PHC. The findings identified an optimal feature subset consisting of eight features, namely AFP, albumin (ALB), alanine aminotransferase (ALT), platelets (PLT), age, alkaline phosphatase (ALP), hemoglobin (Hb), and body mass index (BMI), that achieved the highest classification accuracy of 96.62%. This emphasizes the importance of the collective use of these features in PHC diagnosis. In conclusion, the results provide evidence that the integration of serological and demographic indices together with ensemble learning models, can contribute to the precision of preliminary diagnosis of PHC.

Management of iron deficiency anemia during pregnancy: a midwife-led continuity of care model.

Background: Globally, 36.5% of pregnancies are affected by anemia, particularly in low-and middle-income countries, posing significant risks to maternal and perinatal health. In rural Pakistan, 44.3% of pregnant women suffer from iron deficiency, contributing to the high prevalence of anemia. Limited accessibility to antenatal care exacerbates the challenge, necessitating innovative solutions. This study assessed a midwife-led continuity of care model, utilizing intravenous (IV) iron therapy for the management of anemia in Karachi, Pakistan. Methods: We performed a retrospective analysis of data from a prospective cohort study conducted in two primary healthcare facilities, which employed a community midwife (CMW)-led continuity of care model for antenatal care, including IV iron therapy. We extracted data from February 2021 to March 2022 for women who were diagnosed with anemia based on hemoglobin (Hb) levels, categorized as mild (10.0 to 10.9 g/dL), moderate (7.0 to 9.9 g/dL), or severe (less than 7.0 g/dL). Assessment occurred at the initial antenatal care (ANC) visit to establish baseline anemia severity, and approximately 2 weeks after intravenous (IV) iron therapy administration to evaluate post-treatment changes were considered. Results: We enrolled 114 pregnant women, where the majority presented with moderate (88.6%) anemia. After IV iron treatment, 48.5% improved to normal-mild levels, while 50% remained unchanged. Severe anemia affected 10.5% at baseline; 42% shifted to moderate and 50% to normal-mild post-treatment, with one remaining unchanged (p < 0.001). Among women enrolled in the first and second trimesters, severe anemia improved to normal-mild (50%) and moderate levels (50%) (pre-treatment: n = 10, post-treatment: n = 0), and moderate anemia decreased by 48% (pre-treatment: n = 92, post-treatment: n = 47). Conclusion: Our midwife-led model of care demonstrated an improvement in iron levels among pregnant women. The model addressed the challenges of anemia prevalence in Pakistan and underscored the significance of empowering front-line healthcare providers, such as community midwives (CMWs) for managing these common conditions.

Optimizing primary healthcare experience: assessing client satisfaction in Kaduna State, Northwest Nigeria.

BACKGROUND: Client satisfaction is a multidimensional construct focusing on clients' perceptions and evaluations of the treatment and care received. It is one of the factors affecting the outcomes of healthcare and the use of health services. Therefore, we aimed to assess clients' satisfaction with PHC services in Kaduna State, Northwest Nigeria. METHODOLOGY: A cross-sectional descriptive study was conducted in Kaduna State, Northwest, Nigeria which evaluate the satisfaction of clients and caregivers accessing healthcare in PHC centres. A sample size of 217 was determined using Fisher's formula, with a multi-stage sampling technique used to randomly select eligible respondents, who have accessed at least a PHC service in any of the PHCs in the State were included in the study, A semi-structured, interviewer-administered questionnaire was administered, and the data collected was analyzed using SPSS version 23.0. Appropriate statistical tests were used to examine the association between dependent and independent variables, while predictor variables that showed significant association with the outcome variables were further subjected to logistic regression analysis, to determine factors that affect clients' satisfaction with PHC services. Statistical significance was determined at an alpha level set at 0.05 at a 95% confidence interval. RESULTS: Thirty-one percent of the respondents were satisfied with PHC services in Kaduna State with a mean composite satisfaction score of 3.78 ± 0.67. Age, ethnicity, level of education, and occupational status were factors affecting clients' satisfaction with PHC services among the respondents. On multivariate analysis, age, ethnicity, educational status, and occupational status were significant factors affecting clients' satisfaction with PHC services. Clients of Hausa/Fulani extraction are one and a half times less likely to be satisfied with PHC services when compared to clients from other tribes [aOR = 1.5, 95% CI (1.21-4.67); p = 0.003]. In terms of educational status, clients with formal education are one and a one-third times more likely to be satisfied [aOR = 1.3, 95% CI (0.17-0.94)] with PHC service when compared with their counterparts with informal education (p = 0.034). CONCLUSION: Clients' satisfaction with PHC services in Kaduna State, Northwest Nigeria was sub-optimal. Healthcare providers were recommended to improve their attitude bearing in mind clients' peculiarities.

Study protocol for a pilot quasi-experimental study on oral health education for nurses and community health workers in Nigeria.

Introduction: The primary health care system provides an ideal setting for the integration of oral health into general health care as well as equitable access to oral health care. However, the limited oral health knowledge of primary health care workers necessitates appropriate training before they can participate in health promotion efforts. This pilot training was designed to examine the impact of the Oral Health Education module for Nurses and Community Health Care Workers on their oral health awareness and referral practices. Methods: This study will utilize a quasi-experimental design (pre-and post with a non-equivalent control group) to assess the impact of a five-day pilot oral health education program on the knowledge and referral practices of Nurses and Community Health Workers in primary health care centers in three states in Nigeria-(Lagos, Oyo, and Kano). The training modules were developed based on the six iterative steps described in the intervention mapping framework - needs assessment, highlighting program objectives and outcomes, selection of theory and mode of intervention, designing program based on theory, designing implementation plans, and developing an evaluation plan. Only the intervention group will participate in the full educational training sessions but both groups will complete the pre-and post-intervention questionnaires. Discussion: This pilot training combined the standardized training modules from the recently launched "Oral Health Training Course for Community Health Workers in Africa" and a newly developed maternal and child oral health module by our group using an evidence-based approach. To the best of our knowledge, this is the first program to examine the impact of the standardized OpenWHO modules. The success of this training will lay the foundation for developing a sustained channel for providing oral health education at the primary health care level in Nigeria, West Africa, and Africa.

Physical unclonable function using photonic spin Hall effect.

This study presents a novel method leveraging surface wave-assisted photonic spin Hall effect (PSHE) to construct physical unclonable functions (PUFs). PUFs exploit inherent physical variations to generate unique Challenge-Response pairs, which are critical for hardware security and arise from manufacturing discrepancies, device characteristics, or timing deviations. We explore PSHE generation-based PUF design, expanding existing design possibilities. With recent applications in precise sensing and computing, PSHE offers promising performance metrics for our proposed PUFs, including an inter-Hamming distance of 47.50% , an average proportion of unique responses of 62.5% , and a Pearson correlation coefficient of - 0.198. The PUF token demonstrates robustness to simulated noise. Additionally, we evaluate security using a machine learning-based attack model, employing a multi-layer perceptron (MLP) regression model with a randomized search method. The average accuracy of successful attack prediction is 9.70% for the selected dataset. Our novel PUF token exhibits high non-linearity due to the PSHE effect, resilience to MLP-based attacks, and sensitivity to process variation.

Non-invasive predictors to grade esophageal varices in liver cirrhosis patients.

Background: Portal hypertension commonly occurs due to liver cirrhosis, and esophageal varices (EV) is one of the major complications associated with it. The most common cause of death in liver cirrhosis is EV bleeding. Hence, GE screening for EV is required, which is an invasive procedure. Regular use of endoscopy results in low compliance due to cost and discomfort for patients. Hence, identifying non-invasive markers that could grade EV provides a useful screening tool for family physicians and primary health centers (PHCs) by referring the patient to higher centers for definitive treatment, which could reduce mortality due to variceal bleeding in cirrhotic patients. Aims: To assess non-invasive predictors of grade EV in patients diagnosed with liver cirrhosis. Settings and Design: Cross-sectional study. Methods and Material: A total of 109 patients with liver cirrhosis underwent clinical and biochemical evaluation, USG abdomen with spleen bipolar diameter, ascitic fluid analysis, and upper GE with a grade of EV are recorded. Statistical Analysis Used: SPSS software with Student t-test, Chi-square t-test, analysis of variance, receiver operator characteristic (ROC) curves, and Spearman correlation with 95% CI is used. P <0.05 is considered significant. Results: Aminotransferase to Platelet count Ratio Index (APRI) score >1.815, PC/SD ≤909, and SAAG >1.1g/dl showed EV in liver cirrhosis (P < 0.05). The order of prediction with ROC curves shows APRI score > PC/SD > SAAG. In grading EV, APRI scores of 1.9-2.5 and >2.5 showed small and large EV, respectively (P < 0.05). Conclusions: APRI score may be used in PHC as an early intervention to grade EV and refer the patient to higher centers for definitive treatment. This would prevent the progression of varices to rupture and reduce mortality due to variceal bleeds in liver cirrhosis patients.

Uneven primary healthcare supply of rural doctors and medical equipment in remote China: community impact and the moderating effect of policy intervention.

BACKGROUND: Unequal access to primary healthcare (PHC) has become a critical issue in global health inequalities, requiring governments to implement policies tailored to communities' needs and abilities. However, the place-based facility dimension of PHCs is oversimplified in current healthcare literature, and formulating the equity-oriented PHC spatial planning remains challenging without understanding the multiple impacts of community socio-spatial dynamics, particularly in remote areas. This study aims to push the boundary of PHC studies one step further by presenting a nuanced and dynamic understanding of the impact of community environments on the uneven primary healthcare supply. METHODS: Focusing on Shuicheng, a remote rural area in southwestern China, multiple data are included in this village-based study, i.e., the facility-level healthcare statistics data (2016-2019), the statistical yearbooks, WorldPop, and Chinese GDP's spatial distribution data. We evaluate villages' PHC service capacity using the number of doctors and essential equipment per capita, which are the major components of China's PHC delivery. The indicators describing community environments are selected based on extant literature and China's planning paradigms, including town- and village-level factors. Gini coefficients and local spatial autocorrelation analysis are used to present the divergences of PHC capacity, and multilevel regression model and (heterogeneous) difference in difference model are used to examine the driving role of community environments and the dynamics under the policy intervention. RESULTS: Despite the general improvement, PHC inequalities remain significant in remote rural areas. The village's location, aging, topography, ethnic autonomy, and economic conditions significantly influence village-level PHC capacity, while demographic characteristics and healthcare delivery at the town level are also important. Although it may improve the hardware setting in village clinics (coef. = 0.350), the recent equity-oriented policy attempts may accelerate the loss of rural doctors (coef. = - 0.517). Notably, the associations between PHC and community environments are affected inconsistently by this round of policy intervention. The town healthcare centers with higher inpatient service capacity (coef. = - 0.514) and more licensed doctors (coef. = - 0.587) and nurses (coef. = - 0.344) may indicate more detrimental policy effects that reduced the number of rural doctors, while the centers with more professional equipment (coef. = 0.504) and nurses (coef. = 0.184) are beneficial for the improvement of hardware setting in clinics. CONCLUSIONS: The findings suggest that the PHC inequalities are increasingly a result of joint social, economic, and institutional forces in recent years, underlining the increased complexity of the PHC resource allocation mechanism. Therefore, we claim the necessity to incorporate a broader understanding of community orientation in PHC delivery, particularly the interdisciplinary knowledge of the spatial lens of community, to support its sustainable development. Our findings also provide timely policy insights for ongoing primary healthcare reform in China.

Analyzing Non-urgent Emergency Department Visits: Patterns, Demographics, Motivations, and Triage System Awareness in Al-Qassim.

OBJECTIVE: This cross-sectional descriptive study aimed to ascertain the prevalence of non-urgent cases, investigate gender and age preferences, and explore factors influencing individuals' selection of the emergency department (ED) for non-urgent cases in the Al-Qassim region of Saudi Arabia. METHODS: From July 15, 2022, to December 31, 2022, a structured online questionnaire via a Google Docs survey collected data. The study sampled 425 patients from two prominent Al-Qassim healthcare institutions: Buraydah King Fahad Specialized Hospital and Buraydah Central Hospital. Encompassing patients aged 20 to 80 admitted to the ED between 8:00 and 16:00, concurrent with primary healthcare center availability, the study categorized participants by urgency using the Canadian Triage and Acuity Scale (CTAS) criteria. Data analysis employed descriptive statistics, chi-square tests, and probit regression in R version 4.3.3, with a significance level of p < 0.05 for result interpretation. RESULTS: In Al-Qassim in 2022, 82.4% of ED visitors sought care for non-urgent cases, while 17.6% sought care for urgent cases. No statistically significant relationship was found between age and gender and urgent ED visits. Among those with non-urgent conditions, the top reasons for bypassing primary healthcare services were slow treatment (52.7%), lack of knowledge about primary healthcare (PHC) services (33.9%), and appointment unavailability (5.5%). Evaluation of awareness of the ED triage system showed a significant difference only among patients with excellent awareness. CONCLUSION: The investigation found a higher prevalence of non-urgent cases, especially among females. Challenges in appointment booking, accessibility, and the perception of urgency were key factors leading patients to choose the emergency department over PHC centers. The study emphasized the crucial role of ED triage system awareness and the impact of satisfaction with PHC services on healthcare-seeking behavior, with younger individuals less likely to visit the ED and males more inclined at specific satisfaction levels.

Advocacy, experience sharing and action planning toward raising additional financing for primary health care: spending more and spending better towards universal health coverage.

BACKGROUND: Reallocation of funding to respond the covid-19 pandemic, against a backdrop of longstanding underfunded health systems and high out of pocket expenditures for health, affected access to health services for households, especially those without social protection. These highlighted the urgency in curbing the impact of disruptions on progress towards Universal Health Coverage (UHC) goals. Strategic investments in Primary Health Care (PHC) can help spur the necessary momentum. METHODS: Under the collaborative platform of the Harmonization for Health in Africa's Health Financing Technical Working Group; UNICEF Regional Office for East and Southern Africa and WHO Regional Office for Africa convened the first PHC financing forum for 21 countries across the Eastern and Southern Africa Region. The three-day forum engaged key health and financing decision makers in constructive dialogue to identify practical actions and policy changes needed to accelerate delivery of UHC through improvements in PHC financing mechanisms and arrangements. The forum was attended by over 130 senior policy makers and technicians from governments, United Nations agencies and nonstate actors drawn from within country, regional and affiliating headquarter institutions. RESULTS: The Regional Forum engaged participants in meaningful, and constructive discussions. Five themes emerged (1) regular measurement and monitoring of PHC services and spending (2) increasing investments in PHC (3) enhancing efficiency, effectiveness, and equity of PHC spending, (4) ensuring an enabling environment to invest more and better in PHC, and (5) better partnerships for the realization of commitments. An outcome statement summarizing the main recommendations of the meeting was approved at the end of the forum, and action plans were developed by 14 government delegations to improve PHC financing within country-specific context and priorities. CONCLUSIONS AND RECOMMENDATIONS: The aims of this meeting in augmenting the political will created through the Africa Leadership Meeting (ALM), by catalyzing technical direction for increased momentum for improved health financing across all African countries was achieved. Peer exchanges offered practical approaches countries can take to improve health financing in ways that are suited to regional context providing a channel for incremental improvements to health outcomes in the countries.

Carbon nanotubes integrated photonic barcodes in Herringbone Microfluidics for Multiplex Biomarker Quantification.

Early monitoring of cardiovascular disease (CVD) is crucial for its treatment and prognosis. Hence, highly specific and sensitive detection method is urgently needed. In this study, we propose a novel herringbone microfluid chip with aptamer functionalized core-shell photonic crystal (PhC) barcode integration for high throughput multiplex CVD detection. Based on the PhC derived from co-assembled carboxylated single-wall carbon nanotubes and silicon dioxide nanoparticles, we obtain core-shell PhC barcodes by hydrogel replicating and partially etching. These core-shell PhC barcodes not only retain the original structural colors coding element, but also fully expose a large number of carboxyl elements in the ore for the probe immobilization. We further combine the functionalized barcodes with herringbone groove microfluidic chip to elucidate its acceptability in testing clinical sample. It is demonstrated that the special design of microfluidic chip can significantly enhance fluid vortex resistance and contact frequency, improving the sample capture efficiency and detection sensitivity. These features indicate that our core-shell PhC barcodes-integrated herringbone microfluidic system possesses great potential for multiplex biomarker detection in clinical application.

Interactions between plants and bacterial communities for phytoremediation of petroleum-contaminated soil.

Plants can stimulate the microbes to degrade ubiquitous petroleum hydrocarbons (PHCs), which has prompted a novel view on rhizoremediation. In the present study, the degradation rate of PHCs was investigated and 16S rRNA gene analysis was performed to investigate the PHC-degrading bacteria in petroleum-contaminated soil with different plants. Mirabilis jalapa (M. jalapa) has a higher PHC degradation rate than Lolium perenne (L. perenne) under petroleum contamination. The bacterial diversity in rhizospheric soil was decreased but the relative abundance of Actinobacteriota, Proteobacteria, and Candidatus Saccharibacteria were significant increased on 45 days petroleum-contaminated rhizospheric soil. In addition, the relative expression of PHC degradation-related genes, the content of malic acid and citric acid of the root exudates in the two plants was significantly increased in response to petroleum stress. The content of citric acid increased 11.9 times in M. jalapa and 3.4 times in L. perenne, respectively, in response to petroleum stress. These results indicate that M. jalapa changes the hydrocarbon-degrading microbial community to enhance the degradation of PHCs by root exudates and phytostimulation.

Ventilatory response of peripheral chemoreceptors to hypercapnia during exercise above the respiratory compensation point.

Peripheral hypercapnic chemosensitivity (PHC) is assessed as the change in ventilation in response to a rapid change in carbon dioxide pressures (Pco2). The increase in chemoresponse from rest to subrespiratory compensation point (RCP) exercise intensities is well-defined but less clear at intensities above the RCP when changes in known ventilatory stimulants occur. Twenty healthy subjects (n = 10 females) completed a maximal exercise test on 1 day, and on a subsequent day, transient hypercapnia was used to test PHC at multiple exercise stages. The transient hypercapnia involved two breaths of 10% CO2 repeated five times during each of the following: sitting at rest on the cycle ergometer, cycling at 40% wmax, cycling at 85% Wmax, at rest on the cycle ergometer immediately following the 85% stage, and cycling at 40% Wmax again following the postexercise rest. The PHC was not different across exercise intensities (0.98 ± 0.37 vs. 0.91 ± 0.39 vs. 0.92 ± 0.42 L·min-1·mmHg-1 for first 40% wmax, 85% wmax and second 40% Wmax, respectively (P = 0.45). There were no differences in PHC between presupra-RCP exercise rest and postsupra-RCP exercise rest (0.52 ± 0.23 vs. 0.53 ± 0.24 L·min-1·mmHg-1, P = 0.8003). Using a repeated-measures correlation to account for within-participant changes, there was a significant relationship between the end-tidal Pco2 and PHC for the 85% intensity (r = 0.5, P < 0.0001) when end-tidal Pco2 was dynamic between the trials. We conclude that the physiological changes (e.g., metabolic milieu and temperature) produced with supra-RCP exercise do not further augment PHC, and that the prestimulus end-tidal Pco2 modulates the PHC.NEW & NOTEWORTHY Exercise at intensities above the respiratory compensation point did not further augment peripheral hypercapnic chemosensitivity (PHC). Moreover, the PHC was not different during a preexercise resting state compared with rest immediately after intense exercise. The lack of differences across both comparisons suggests that exercise itself appears to sensitize the PHC.