High-pressure Synthesis of Cobalt Polynitrides: Unveiling Intriguing Crystal Structures and Nitridation Behavior.

In this study, we conduct extensive high-pressure experiments to investigate phase stability in the cobalt-nitrogen system. Through a combination of synthesis in a laser-heated diamond anvil cell, first-principles calculations, Raman spectroscopy, and single-crystal X-ray diffraction, we establish the stability fields of known high-pressure phases, hexagonal NiAs-type CoN, and marcasite-type CoN2 within the pressure range of 50-90 GPa. We synthesize and characterize previously unknown nitrides, Co3N2, Pnma-CoN and two polynitrides, CoN3 and CoN5, within the pressure range of 90-120 GPa. Both polynitrides exhibit novel types of polymeric nitrogen chains and networks. CoN3 feature branched-type nitrogen trimers (N3) and CoN5 show π-bonded nitrogen chain. As the nitrogen content in the cobalt nitride increases, the CoN6 polyhedral frameworks transit from face-sharing (in CoN) to edge-sharing (in CoN2 and CoN3), and finally to isolated (in CoN5). Our study provides insights into the intricate interplay between structure evolution, bonding arrangements, and high-pressure synthesis in polynitrides, expanding the knowledge for the development of advanced energy materials.

Marek's disease virus US3 protein kinase phosphorylates chicken HDAC 1 and 2 and regulates viral replication and pathogenesis.

Marek's disease virus (MDV) is a potent oncogenic alphaherpesvirus that elicits a rapid onset of malignant T-cell lymphomas in chickens. Three MDV types, including GaHV-2 (MDV-1), GaHV-3 (MDV-2) and MeHV-1 (HVT), have been identified and all encode a US3 protein kinase. MDV-1 US3 is important for efficient virus growth in vitro. To study the role of US3 in MDV replication and pathogenicity, we generated an MDV-1 US3-null virus and chimeric viruses by replacing MDV-1 US3 with MDV-2 or HVT US3. Using MD as a natural virus-host model, we showed that both MDV-2 and HVT US3 partially rescued the growth deficiency of MDV-1 US3-null virus. In addition, deletion of MDV-1 US3 attenuated the virus resulting in higher survival rate and lower MDV specific tumor incidence, which could be partially compensated by MDV-2 and HVT US3. We also identified chicken histone deacetylase 1 (chHDAC1) as a common US3 substrate for all three MDV types while only US3 of MDV-1 and MDV-2 phosphorylate chHDAC2. We further determined that US3 of MDV-1 and HVT phosphorylate chHDAC1 at serine 406 (S406), while MDV-2 US3 phosphorylates S406, S410, and S415. In addition, MDV-1 US3 phosphorylates chHDAC2 at S407, while MDV-2 US3 targets S407 and S411. Furthermore, biochemical studies show that MDV US3 mediated phosphorylation of chHDAC1 and 2 affect their stability, transcriptional regulation activity, and interaction network. Using a class I HDAC specific inhibitor, we showed that MDV US3 mediated phosphorylation of chHDAC1 and 2 is involved in regulation of virus replication. Overall, we identified novel substrates for MDV US3 and characterized the role of MDV US3 in MDV pathogenesis.

Indicator-activities to apply primary health care principles in national or large-scale community health worker programs in low-and middle-income countries: a Delphi exercise.

INTRODUCTION: Primary Health Care (PHC) gained considerable momentum in the past four decades and led to improved health outcomes across a wide variety of settings. In low-and middle-income countries (LMICs), national or large-scale Community Health Worker Programs (CHWPs) are considered as vehicles to incorporate PHC principles into healthcare provision and are an essential aspect of the PHC approach to achieve health for all and sustainable development goals. The success of CHWPs is rooted in the application of PHC principles. However, there is evidence that shows patchy implementation of PHC principles across national CHWPs in LMICs. This may reflect the lack of information on what activities would illustrate the application of these principles in CHWPs. This study aimed to identify a set of core/indicator-activities that reflect the application of PHC principles by CHWPs in LMICs. METHODS: A two-round modified Delphi study was undertaken with participants who have extensive experience in planning, implementation and evaluation of CHWPs. Survey design and analysis was guided by the four PHC principles namely Universal Health Coverage, Community Participation, Intersectoral Coordination and Appropriateness. Responses were collected using a secure online survey program (survey monkey). In round one, participants were asked to list 'core activities' that would reflect the application of each PHC principle and its sub-attributes and challenges to apply these principles in CHWPs. In round two, participants were asked to select whether they agree or disagree with each of the activities and challenges. Consensus was set a priori at 70% agreement of participants for each question. RESULTS: Seventeen participants from 15 countries participated in the study. Consensus was reached on 59 activities reflecting the application of PHC principles by CHWPs. Based on participants' responses, a set of 29 indicator-activities for the four PHC principles was developed with examples for each indicator-activity. CONCLUSION: These indicator-activities may provide guidance on how PHC principles can be implemented in CHWPs. They can be used in the development and evaluation of CHWPs, particularly in their application of PHC principles. Future research may focus on testing the utility of indicator-activities on CHWPs in LMICs.

The role of Meq-vIL8 in regulating Marek's disease virus pathogenesis.

Marek's disease virus (MDV) is a highly cell-associated oncogenic alphaherpesvirus that causes T cell lymphoma in chickens. MDV-encoded Meq and vIL8 proteins play important roles in transformation and early cytolytic infection, respectively. Previous studies identified a spliced transcript, meq-vIL8, formed by alternative splicing of meq and vIL8 genes in MDV lymphoblastoid tumour cells. To determine the role of Meq-vIL8 in MDV pathogenesis, we generated a recombinant MDV (MDV-meqΔSD) by mutating the splice donor site in the meq gene to abrogate the expression of Meq-vIL8. As expected, our results show that MDV-meqΔSD virus grows similarly to the parental and revertant viruses in cell culture, suggesting that Meq-vIL8 is dispensable for MDV growth in vitro. We further characterized the pathogenic properties of MDV-meqΔSD virus in chickens. Our results show that lack of Meq-vIL8 did not affect virus replication during the early cytolytic phase, as determined by immunohistochemistry analysis and/or viral genome copy number, but significantly enhanced viral DNA load in the late phase of infection in the spleen and brain of infected chickens. In addition, we observed that abrogation of Meq-vIL8 expression reduced the mean death time and increased the prevalence of persistent neurological disease, common features of highly virulent strains of MDV, in inoculated chickens. In conclusion, our study shows that Meq-vIL8 is an important virulence factor of MDV.

High-Pressure Synthesis of Dirac Materials: Layered van der Waals Bonded BeN_{4} Polymorph.

High-pressure chemistry is known to inspire the creation of unexpected new classes of compounds with exceptional properties. Here, we employ the laser-heated diamond anvil cell technique for synthesis of a Dirac material BeN_{4}. A triclinic phase of beryllium tetranitride tr-BeN_{4} was synthesized from elements at ∼85 GPa. Upon decompression to ambient conditions, it transforms into a compound with atomic-thick BeN_{4} layers interconnected via weak van der Waals bonds and consisting of polyacetylene-like nitrogen chains with conjugated π systems and Be atoms in square-planar coordination. Theoretical calculations for a single BeN_{4} layer show that its electronic lattice is described by a slightly distorted honeycomb structure reminiscent of the graphene lattice and the presence of Dirac points in the electronic band structure at the Fermi level. The BeN_{4} layer, i.e., beryllonitrene, represents a qualitatively new class of 2D materials that can be built of a metal atom and polymeric nitrogen chains and host anisotropic Dirac fermions.

Direct Measurement of the Affinity between tBid and Bax in a Mitochondria-Like Membrane.

The execution step in apoptosis is the permeabilization of the outer mitochondrial membrane, controlled by Bcl-2 family proteins. The physical interactions between the different proteins in this family and their relative abundance literally determine the fate of the cells. These interactions, however, are difficult to quantify, as they occur in a lipid membrane and involve proteins with multiple conformations and stoichiometries which can exist both in soluble and membrane. Here we focus on the interaction between two core Bcl-2 family members, the executor pore-forming protein Bax and the truncated form of the activator protein Bid (tBid), which we imaged at the single particle level in a mitochondria-like planar supported lipid bilayer. We inferred the conformation of the proteins from their mobility, and detected their transient interactions using a novel single particle cross-correlation analysis. We show that both tBid and Bax have at least two different conformations at the membrane, and that their affinity for one another increases by one order of magnitude (with a 2D-KD decreasing from ≃1.6µm-2 to ≃0.1µm-2) when they pass from their loosely membrane-associated to their transmembrane form. We conclude by proposing an updated molecular model for the activation of Bax by tBid.

Stabilization of Polynitrogen Anions in Tantalum-Nitrogen Compounds at High Pressure.

The synthesis of polynitrogen compounds is of great importance due to their potential as high-energy-density materials (HEDM), but because of the intrinsic instability of these compounds, their synthesis and stabilization is a fundamental challenge. Polymeric nitrogen units which may be stabilized in compounds with metals at high pressure are now restricted to non-branched chains with an average N-N bond order of 1.25, limiting their HEDM performances. Herein, we demonstrate the synthesis of a novel polynitrogen compound TaN5 via a direct reaction between tantalum and nitrogen in a diamond anvil cell at circa 100 GPa. TaN5 is the first example of a material containing branched all-single-bonded nitrogen chains [N5 5- ]∞ . Apart from that we discover two novel Ta-N compounds: TaN4 with finite N4 4- chains and the incommensurately modulated compound TaN2-x , which is recoverable at ambient conditions.

Dinitrogen as a Universal Electron Acceptor in Solid-State Chemistry: An Example of Uncommon Metallic Compounds Na3(N2)4 and NaN2.

With the exception of lithium, alkali metals do not react with elemental nitrogen either at ambient conditions or at elevated temperatures, requiring the search for alternative synthetic routes to their nitrogen-containing compounds. Here using a controlled decomposition of sodium azide (NaN3) at high pressure conditions, we synthesize two novel compounds, Na3(N2)4 and NaN2, both containing dinitrogen anions. NaN2 synthesized at 4 GPa might be the common intermediate in high-pressure solid-state metathesis reactions, where NaN3 is used as a source of nitrogen, while Na3(N2)4 opens a new class of compounds, where [N2] units accommodate a noninteger formal charge of 0.75-. This finding can dramatically extend the expected compositions in other group 1 and 2 metal-nitrogen systems. Electronic structure calculations show the metallic character for both compounds.

High-Pressure Synthesis of Metal-Inorganic Frameworks Hf4 N20 ⋠N2 , WN8 ⋠N2 , and Os5 N28 ⋠3 N2 with Polymeric Nitrogen Linkers.

Polynitrides are intrinsically thermodynamically unstable at ambient conditions and require peculiar synthetic approaches. Now, a one-step synthesis of metal-inorganic frameworks Hf4 N20 ⋅N2 , WN8 ⋅N2 , and Os5 N28 ⋅3 N2 via direct reactions between elements in a diamond anvil cell at pressures exceeding 100 GPa is reported. The porous frameworks (Hf4 N20 , WN8 , and Os5 N28 ) are built from transition-metal atoms linked either by polymeric polydiazenediyl (polyacetylene-like) nitrogen chains or through dinitrogen units. Triply bound dinitrogen molecules occupy channels of these frameworks. Owing to conjugated polydiazenediyl chains, these compounds exhibit metallic properties. The high-pressure reaction between Hf and N2 also leads to a non-centrosymmetric polynitride Hf2 N11 that features double-helix catena-poly[tetraz-1-ene-1,4-diyl] nitrogen chains [-N-N-N=N-]∞ .

Opacity and conductivity measurements in noble gases at conditions of planetary and stellar interiors.

The noble gases are elements of broad importance across science and technology and are primary constituents of planetary and stellar atmospheres, where they segregate into droplets or layers that affect the thermal, chemical, and structural evolution of their host body. We have measured the optical properties of noble gases at relevant high pressures and temperatures in the laser-heated diamond anvil cell, observing insulator-to-conductor transformations in dense helium, neon, argon, and xenon at 4,000-15,000 K and pressures of 15-52 GPa. The thermal activation and frequency dependence of conduction reveal an optical character dominated by electrons of low mobility, as in an amorphous semiconductor or poor metal, rather than free electrons as is often assumed for such wide band gap insulators at high temperatures. White dwarf stars having helium outer atmospheres cool slower and may have different color than if atmospheric opacity were controlled by free electrons. Helium rain in Jupiter and Saturn becomes conducting at conditions well correlated with its increased solubility in metallic hydrogen, whereas a deep layer of insulating neon may inhibit core erosion in Saturn.

Development and evaluation of a passive trunk support system for Duchenne muscular dystrophy patients.

BACKGROUND: Patients with Duchenne muscular dystrophy gradually lose the ability to use different muscles of their body. Consequently, they lose the ability to stabilize their trunk against gravity. This hinders them to effectively perform different daily activities. In this paper, we describe the design, realization and evaluation of a trunk orthosis for these patients that should allow them to move their trunk and maintain stability. METHOD: This study aimed to primarily assess the effectiveness of the trunk support system in terms of unloading of trunk muscles, so only healthy participants were recruited for this phase of the study. Measurements were done on 10 healthy participants (23.4±2.07 [M±SD] years old, average body weight 68.42±24.22 [M±SD] kg). The experiment comprised maintaining a constant trunk posture in three different device conditions (control without orthosis and two conditions with different configurations of the orthosis), at four different flexion angles (10°, 20°, 30°, 40°) for each device condition and for two load conditions (with and without stretching the arms). Electromyography (EMG) signals from the trunk muscles were measured to estimate activation levels of the trunk muscles (iliocostalis, longissimus, external oblique and rectus abdominis) and a motion capture system was used to record the movement of the participants during the experiment. RESULTS: Wearing the orthosis caused reductions in longissimus and iliocostalis activity. The average muscle activity level was 5%-10% of maximum voluntary contraction in the unsupported conditions for those particular muscles. This level was reduced to 3%-9% of maximal voluntary contraction for the supported conditions. No effect on external oblique and rectus abdominis activity was observed. Moreover, no pain or discomfort was reported by any of the participants during the experiment. The results from the current experiment also suggests the necessity of lumber stabilizing systems while using trunk orthosis. CONCLUSION: The developed orthosis reduces trunk muscle activation level and provides a solid step for further development of support systems for Duchenne muscular dystrophy patients. TRIAL REGISTRATION: The current study was approved by the medical ethics committee Arnhem-Nijmegen (study number: NL53143.091.15 ), The Netherlands.

Optical Properties of Fluid Hydrogen at the Transition to a Conducting State.

We use fast transient transmission and emission spectroscopies in the pulse laser heated diamond anvil cell to probe the energy-dependent optical properties of hydrogen at pressures of 10-150 GPa and temperatures up to 6000 K. Hydrogen is absorptive at visible to near-infrared wavelengths above a threshold temperature that decreases from 3000 K at 18 GPa to 1700 K at 110 GPa. Transmission spectra at 2400 K and 141 GPa indicate that the absorptive hydrogen is semiconducting or semimetallic in character, definitively ruling out a first-order insulator-metal transition in the studied pressure range.

Effects of Interaction Between Ventricular Assist Device Assistance and Autoregulated Mock Circulation Including Frank-Starling Mechanism and Baroreflex.

A mock heart circulation loop (MHCL) is a hydraulic model simulating the human circulatory system. It allows in vitro investigations of the interaction between cardiac assist devices and the human circulatory system. In this study, a preload sensitive MHCL, the MHCLAUTO , was developed to investigate the interaction between the left ventricle and left ventricular assist devices (LVADs). The Frank-Starling mechanism was modeled by regulating the stroke volume (SV) based on the measured mean diastolic left atrial pressure (MLAPdiast ). The baroreflex autoregulation mechanism was implemented to maintain a constant mean aortic pressure (MAP) by varying ventricular contractility (Emax ), heart rate (HR), afterload/systemic vascular resistance (SVR) and unstressed venous volume (UVV). The DP3 blood pump (Medos Medizintechnik GmbH) was used to simulate the LVAD. Characteristic parameters were measured in pathological conditions both with and without LVAD to assess the hemodynamic effect of LVAD on the MHCLAUTO . The results obtained from the MHCLAUTO show a high correlation to literature data. The study demonstrates the possibility of using the MHCLAUTO as a research tool to better understand the physiological interactions between cardiac implants and human circulation.

Impact of the Follicular Lymphoma International Prognostic Index risk categorization on survival of patients with follicular lymphoma in Pakistani population: a single centre experience.

OBJECTIVE: To determine the impact of Follicular Lymphoma International Prognostic Index risk categorisation on the survival of patients with follicular lymphoma treated in one centre. METHOD: The retrospective study comprised follicular lymphoma patients treated from 1997 to 2010 at Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore. Their baseline prognostic index score, stage, bone marrow involvement and high-grade transformation were recorded. Risk categorisation was done according to the index score. SPSS 19 was used for statistical analysis. RESULTS: Median age of the 70 patients studied was 54 years (range: 23-98). There were 42 (60%) males. Overall, 58 (83%) patients presented with stage III/IV disease. Bone marrow was involved in 42 (60%) cases. High-grade transformation was reported in 12 (17.1%). According to risk categorisation, 21 (30%) were low risk, 21 (30%) intermediate and 28 (40%) were in high-risk category. Patients were treated with standard chemotherapy. Median follow-up was 3 years (range: 1-9). Median overall survival was 4.1 years (95% Cl: 4.7-6.4).The Kaplan Meier estimated overall survival at 5 years was 26 (43%). Five-year overall survival in the low, intermediate and high risk groups was 14 (66%), 10 (47%) and 7 (25%), respectively (p < 0.02). CONCLUSION: The Follicular Lymphoma International Prognostic Index showed significant prognostic value with high scores having poor overall survival compared to patients with low and intermediate scores.

Rose Angina Questionnaire: validation with cardiologists' diagnoses to detect coronary heart disease in Bangladesh.

AIM/OBJECTIVES: The study aimed to validate the Rose Angina Questionnaire (RAQ) to detect coronary heart disease (CHD) by comparing with cardiologists' diagnoses in Bangladesh. METHODS: Patients aged 40-75 years attending to two cardiac hospitals were diagnosed as either CHD positive or CHD negative by cardiologists. The RAQ was used to reclassify them into CHD positive [RAQ] and CHD negative [RAQ]. FINDINGS: There were 302 CHD positive [cardiologists] and 302 CHD negative [cardiologists] individuals. The RAQ reclassified 194 individuals as CHD positive [RAQ] and 409 individuals as CHD negative [RAQ]. Therefore, the RAQ had 53% sensitivity and 89% specificity. There was no difference in sensitivity and specificity during subgroup analyzes by age and gender; the sensitivity was higher among people from lower socio-economic status. CONCLUSION: The RAQ, having moderate sensitivity but high specificity to detect CHD, can be used to screen individuals at risk of CHD in large-scale epidemiological surveys.

The PNG Midwifery Leadership Buddy Program: An evaluation.

PROBLEM: Papua New Guinea (PNG) has a high rate of preventable maternal and neonatal deaths. BACKGROUND: Developing midwifery leadership is vital to addressing the current deficits in health outcomes for women and their babies. The PNG Midwifery Leadership Buddy Program responds to this need through leadership training and partnering of midwives across PNG and Australia. Participants in the program undertake a workshop in Port Moresby and commit to a 12-month peer support relationship with a midwife 'buddy'. AIM: To evaluate participants' experiences of the Buddy Program and the impact of the program on leadership skills. METHODS: All 23 midwives who had completed the program were invited to participate in the evaluation. The study used a concurrent mixed methods approach. Qualitative data were collected via interviews and then thematically analysed. Quantitative data were collected via a survey and analysed with descriptive statistics, then findings were triangulated. FINDINGS: Participants reported increased confidence for leadership, action and advocacy. Numerous quality improvement projects were implemented in health services in PNG. Challenges to the success of the program included technological limitations, cultural differences and the COVID-19 pandemic. DISCUSSION: Participants reported the PNG Midwifery Leadership Buddy Program was successful in increasing their leadership skills and collaborative opportunities, as well as strengthening midwifery more broadly. While there were barriers, most participants valued the experience and believed it benefited them professionally and personally CONCLUSION: The Buddy Program provides a practical model for building midwifery leadership capacity that may be transferrable to other contexts.

Structural and chemical properties of the nitrogen-rich energetic material triaminoguanidinium 1-methyl-5-nitriminotetrazolate under pressure.

The structural and chemical properties of the bi-molecular, hydrogen-bonded, nitrogen-rich energetic material triaminoguanidinium 1-methyl-5-nitriminotetrazolate C(3)H(12)N(12)O(2) (TAG-MNT) have been investigated at room pressure and under high pressure isothermal compression using powder x-ray diffraction and Raman and infrared spectroscopy. A stiffening of the equation of state and concomitant structural relaxation between 6 and 14 GPa are found to correlate with Raman mode disappearances, frequency discontinuities, and changes in the pressure dependence of modes. These observations manifest the occurrence of a reversible martensitic structural transformation to a new crystalline phase. The onset and vanishing of Fermi resonance in the nitrimine group correlate with the stiffening of the equation of state and phase transition, suggesting a possible connection between these phenomena. Beyond 15 GPa, pressure induces irreversible chemical reactions, culminating in the formation of a polymeric phase by 60 GPa.

Concomitant illnesses in pregnancy in Indonesia: A health systems analysis at a District level.

BACKGROUND: In LMICs, including Indonesia, there is a rising burden of non-communicable diseases (NCDs) with a prevailing burden of infectious diseases, including among pregnant women. The Indonesian health system faces significant challenges to provide effective care for infectious diseases, and even more so, NCDs. This is concerning due to the greater vulnerability of pregnant women to complications caused by concomitant illnesses (NCDs and infectious diseases), and the need for complex, integrated healthcare between maternal care and other health services. METHODS: The objective of this study was to understand supporting factors and challenges of the health system to providing care for concomitant illnesses in pregnancy and how it may be improved. Semi-structured interviews were conducted with sixteen key stakeholders, including health providers and health service managers, involved in maternal healthcare for concomitant illnesses at a District level in Indonesia. The study was conducted in Kutai Kartanegara District of East Kalimantan. Analysis was conducted using framework analysis to identify themes from transcripts. RESULTS: Supporting factors of the health system to provide care for concomitant illness in pregnancy included collaboration between health providers and health services, availability of screening and diagnostic tools, and access to universal healthcare coverage and financial subsidies. Common challenges included knowledge and awareness of concomitant illnesses among health providers, competency to diagnose and/or manage concomitant illnesses, and inappropriate referrals. Suggested improvements identified to address these gaps included increasing education and refresher training for healthcare providers and strengthening referrals between primary and hospital care. CONCLUSIONS: The findings identified gaps in the health system to provide care for concomitant illnesses in pregnancy in Indonesia that need to be strengthened. More evidence-based research is needed to guide the implementation of policy and practice interventions for the health system to deal with a broader range of concomitant illnesses in pregnancy, particularly NCDs.

Chronic hepatitis B management in six South Australian Aboriginal community controlled health services.

BACKGROUND: Chronic hepatitis B is a significant public health issue; however, there is limited understanding of the engagement in primary health care of Aboriginal people living with chronic hepatitis B (CHB). METHODS: To better understand the management of CHB, diagnostic reports and case note audits were conducted in six South Australian Aboriginal community controlled health services. The audits covered the initial assessment, CHB monitoring, and hepatocellular carcinoma screening. The initial assessment was reviewed by auditing client clinical records for the first 12months from the date of diagnosis, whereas CHB monitoring and hepatocellular carcinoma screening were determined by auditing a 12-month sample period (January to December 2019). Associations with CHB monitoring were determined using a Chi-squared test and Fisher's exact test P -values, as appropriate. RESULTS: There were 50 current clients with a diagnosis of CHB at the time of the audit (January 2020). Testing was incomplete for the initial assessment, CHB monitoring and hepatocellular carcinoma screening. There were significant associations between the increased likelihood of accessing monitoring and the number of times a person attended an Aboriginal community controlled health service, accessing care in a more remote region, having a documented recall and having a GP management plan containing CHB. CONCLUSION: Through providing evidence of significant associations between having a recall set and GP management plans with increased uptake of disease monitoring, this study has highlighted areas for improvement in clinical management.

Application of primary healthcare principles in national community health worker programmes in low-income and middle-income countries: a scoping review.

OBJECTIVE: To identify which primary healthcare (PHC) principles are reflected in the implementation of national community health worker (CHW) programmes and how they may contribute to the outcomes of these programmes in the context of low-income and middle-income countries (LMICs). DESIGN: Scoping review. DATA SOURCES: A systematic search was conducted through PubMed, CINAHL, EMBASE and Scopus databases. ELIGIBILITY CRITERIA: The review considered published primary studies on national programmes, projects or initiatives using the services of CHWs in LMICs focused on maternal and child health. We included only English language studies. Excluded were programmes operated by non-government organisations, study protocols, reviews, commentaries, opinion papers, editorials and conference proceedings. DATA EXTRACTION AND SYNTHESIS: We reviewed the application of four PHC principles (universal health coverage, community participation, intersectoral coordination and appropriateness) in the CHW programme's objectives, implementation and stated outcomes. Data extraction was undertaken systematically in an excel spreadsheet while the findings were synthesised in a narrative manner. The quality appraisal of the selected studies was not performed in this scoping review. RESULTS: From 1280 papers published between 1983 and 2019, 26 met the inclusion criteria. These 26 papers included 14 CHW programmes from 13 LMICs. Universal health coverage and community participation were the two commonly reported PHC principles, while intersectoral coordination was generally missing. Similarly, the cultural acceptability aspect of the principle of appropriateness was present in all programmes as these programmes select CHWs from within the communities. Other aspects, particularly effectiveness, were not evident. CONCLUSION: The implementation of PHC principles across national CHW programmes in LMICs is patchy. For comprehensiveness and improved health outcomes, programmes need to incorporate all attributes of PHC principles. Future research may focus on how to incorporate more attributes of PHC principles while implementing national CHW programmes in LMICs. Better documentation and publications of CHW programme implementation are also needed.