Operative Management of Y-Shaped Metatarsal with Biphalangeal Sixth Toe.

BACKGROUND: In the literature, there is no consensus regarding the surgical management of postaxial polydactyly, and few cases of polymetatarsia with polydactyly have been reported. Treatment of the complete deformity will prevent further foot and gait disorders. OBJECTIVE: To identify literature relevant to the operative management of Y-shaped metatarsal with biphalangeal sixth toe and related skin and wound care to improve surgical treatment protocols from a clinical experience perspective. DATA SOURCES: The authors searched several electronic databases in December 2022 for articles related to postaxial polysyndactyly in the feet and polymetatarsia. Databases searched included PubMed, SciELO, ScienceDirect, Cochrane Database of Systematic Reviews, and Google Scholar gray literature. STUDY SELECTION: Two independent researchers conducted the searches and read the article titles and abstracts. Studies were included if they were narrative reviews, case studies, or observational studies; written in English or Spanish; and published between 2012 and 2022. Nonhuman studies were excluded. Studies that met the inclusion criteria were fully evaluated. Disagreements between reviewers were resolved by consensus, and when there was no consensus, a senior researcher was consulted. DATA EXTRACTION: The following data were extracted from the included studies using a standardized form: author and year of publication, study type, number of participants, sex, polydactyly location, polymetatarsia, type of polydactyly, participants' history of hereditary associated diseases or malformations, treatment, removal criteria, and timing of surgery. DATA SYNTHESIS: Authors evaluated 11 studies of postaxial polydactyly that included a total of 153 participants (64 men, 89 women). They also document their clinical experience with a surgical technique used in cases of bilateral postaxial polydactyly of the foot with a Y-shaped metatarsal with biphalangeal sixth toe. CONCLUSIONS: Surgical correction with lateral removal of the sixth toe is a resolutive treatment to improve the functionality of the foot, its aesthetic appearance, and the patient's quality of life. Case-specific treatment should be applied and tailored to meet the individual needs. The biomechanics of gait and shoe problems in these patients improve with surgical treatment, without presenting secondary aesthetic problems in skin care.

[Convergent and discriminative validity of the Frail-VIG index with the Pfeiffer test in people cared for in home care]. / Validez convergente y discriminativa del índice Frágil-VIG con el test de Pfeiffer en personas atendidas en atención domiciliaria.

INTRODUCTION: The Frail-VIG index-and the Pfeiffer test are measurements used in Primary Care for assessment frailty and the cognitive impairment screening. The Frail-VIG index is a multidimensional instrument that allows a rapid assessment of the degree of frailty in the context of clinical practice. OBJECTIVE: Our aim was to investigate the convergent and discriminative validity of the Frail-VIG index with regard to Pfeiffer test value. DESIGN: A cross-sectional study. SITE: Two urban Primary Health Care centres of the Catalan Institute of Health, Barcelona (Spain). PARTICIPANTS: All people included under a home care programme during the year 2018. No exclusion criteria were applied. MAIN MEASUREMENTS: We used the Frail-VIG index to measure frailty and the Pfeiffer test to cognitive impairment screening. Trained nurses administered both instruments during face-to-face assessments in a participant's home during usual care. The relationships between both instruments were examined using Pearson's correlation coefficient. RESULTS: A total of 412 participants were included. Frail-VIG score and Pfeiffer test value were moderately correlated (r=0.564; P<0.001). Non-frail people had a lower risk of developing cognitive impairment than moderate to severe frail people. The value of the Pfeiffer test increased significantly as the Frail-VIG index score also increased. CONCLUSIONS: Frail-VIG index demonstrated a convergent validity with the Pfeiffer test. Its discriminative validity was optimal, as their scores showed an excellent capacity to differentiate between people with a higher and lower risk of developing cognitive impairment. These findings provide additional pieces of evidence for construct validity of the Frail-VIG index.

Impacts of the feedback loop between sense-antisense RNAs in regulating circadian rhythms.

Antisense transcripts are a unique group of non-coding RNAs that are transcribed from the opposite strand of a sense coding gene in an antisense orientation. Even though they do not encode a protein, these transcripts play a regulatory role in a variety of biological processes, including circadian rhythms. We and others found an antisense transcript, Per2AS , that is transcribed from the strand opposite the sense transcript Period2 ( Per2 ) and exhibits a rhythmic and antiphasic expression pattern compared to Per2 in mouse. By assuming that Per2AS and Per2 mutually repress each other, our previous mathematical model predicted that Per2AS regulates the robustness and the amplitude of circadian rhythms. In this study, we revised our previous model and developed a new mathematical model that mechanistically described the mutually repressive relationship between Per2 and Per2AS via transcriptional interference. We found that the simulation results are largely consistent with experimental observations including the counterintuitive ones that could not be fully explained by our previous model. These results indicate that our revised model serves as a foundation to build more detailed models in the future to better understand the impact of Per2AS-Per2 interaction in the mammalian circadian clock. Our mechanistic description of Per2AS-Per2 interaction can also be extended to other mathematical models that involve sense-antisense RNA pairs that mutually repress each other.

Volatiles of symbiotic bacterial origin explain ectoparasitism and fledging success of hoopoes.

BACKGROUND: Some parasites use olfactory cues to detect their hosts and, since bacterial symbionts are partially responsible for animal odours, they could influence host parasitism. By autoclaving nest materials of hoopoe (Upupa epops) nests before reproduction started, we explored the hypothetical links between host-associated bacteria, volatiles and parasitism. During the nestling stage, we (i) estimated the level of ectoparasitism by chewing lice (Suborder Mallophaga) in adult hoopoe females and by Carnus haemapterus flies in nestlings, and (ii) characterized microbial communities and volatile profiles of nest environments (nest material and nest cavity, respectively) and uropygial secretions. RESULTS: Experimental nests had less diverse bacterial communities and more diverse volatile profiles than control nests, while occupants experienced lower intensity of parasitism in experimental than in control nests. The experiment also affected beta diversity of the microbial communities of nest material and of the volatiles of the nestling uropygial secretions. Moreover, microbial communities of uropygial secretions and of nest materials covaried with their volatile profiles, while the volatile profile of the bird secretions explained nest volatile profile. Finally, a subset of the volatiles and bacteria detected in the nest material and uropygial secretions were associated with the ectoparasitism intensity of both adult females and nestlings, and with fledging success. CONCLUSIONS: These results show that a component of animal odours is linked with the microbial communities of the host and its reproductive environment, and emphasize that the associations between bacteria, ectoparasitism and reproductive success are partially mediated by volatiles of bacterial origin. Future work should focus on mechanisms underlying the detected patterns.

The long-term effects of dapagliflozin in chronic kidney disease: a time-to-event analysis.

BACKGROUND AND HYPOTHESIS: Chronic kidney disease (CKD) presents a significant clinical and economic burden to healthcare systems worldwide, which increases considerably with progression towards kidney failure. The DAPA-CKD trial demonstrated that patients with or without type 2 diabetes (T2D) who were treated with dapagliflozin experienced slower progression of CKD versus placebo. Understanding the effect of long-term treatment with dapagliflozin on the timing of kidney failure beyond trial follow-up can assist informed decision-making by healthcare providers and patients. The study objective was therefore to extrapolate the outcome-based clinical benefits of treatment with dapagliflozin in patients with CKD via a time-to-event analysis using trial data. METHODS: Patient-level data from the DAPA-CKD trial were used to parameterise a closed cohort-level partitioned survival model that predicted time-to-event for key trial endpoints (kidney failure, all-cause mortality, sustained decline in kidney function, and hospitalisation for heart failure). Data were pooled with a subpopulation of the DECLARE-TIMI 58 trial to create a combined CKD population spanning a range of CKD stages; a parallel survival analysis was conducted in this population. RESULTS: In the DAPA-CKD and pooled CKD populations, treatment with dapagliflozin delayed time to first event for kidney failure, all-cause mortality, sustained decline in kidney function, and hospitalisation for heart failure. Attenuation of CKD progression was predicted to slow the time to kidney failure by 6.6 years (dapagliflozin: 25.2, 95%CI: 19.0-31.5; standard therapy: 18.5, 95%CI: 14.7-23.4) in the DAPA-CKD population. A similar result was observed in the pooled CKD population with an estimated delay of 6.3 years (dapagliflozin: 36.0, 95%CI: 31.9-38.3; standard therapy: 29.6, 95%CI: 25.5-34.7). CONCLUSION: Treatment with dapagliflozin over a lifetime time horizon may considerably delay the mean time to adverse clinical outcomes for patients who would go on to experience them, including those at modest risk of progression.

Oculomotor Dysfunction in Idiopathic and LRRK2-Parkinson's Disease and At-Risk Individuals.

Background: Video-oculography constitutes a highly-sensitive method of characterizing ocular movements, which could detect subtle premotor changes and contribute to the early diagnosis of Parkinson's disease (PD). Objective: To investigate potential oculomotor differences between idiopathic PD (iPD) and PD associated with the G2019S variant of LRRK2 (L2PD), as well as to evaluate oculomotor function in asymptomatic carriers of the G2019S variant of LRRK2. Methods: The study enrolled 129 subjects: 30 PD (16 iPD, 14 L2PD), 23 asymptomatic carriers, 13 non-carrier relatives of L2PD patients, and 63 unrelated HCs. The video-oculographic evaluation included fixation, prosaccade, antisaccade, and memory saccade tests. Results: We did not find significant differences between iPD and L2PD. Compared to controls, PD patients displayed widespread oculomotor deficits including larger microsaccades, hypometric vertical prosaccades, increased latencies in all tests, and lower percentages of successful antisaccades and memory saccades. Non-carrier relatives showed oculomotor changes with parkinsonian features, such as fixation instability and hypometric vertical saccades. Asymptomatic carriers shared multiple similarities with PD, including signs of unstable fixation and hypometric vertical prosaccades; however, they were able to reach percentages of successful antisaccade and memory saccades similar to controls, although at the expense of longer latencies. Classification accuracy of significant oculomotor parameters to differentiate asymptomatic carriers from HCs ranged from 0.68 to 0.74, with BCEA, a marker of global fixation instability, being the parameter with the greatest classification accuracy. Conclusions: iPD and LRRK2-G2019S PD patients do not seem to display a differential oculomotor profile. Several oculomotor changes in asymptomatic carriers of LRRK2 mutations could be considered premotor biomarkers.

The Perceived Quality of Life of Older People in Spain Who Care for Grandchildren and Related Variables: A Mixed Methods Study.

Grandparental care of grandchildren is a prevalent social phenomenon. This study explores the perceptions of health-related quality of life of grandparents caring for their grandchildren. A mixed methods design was developed. In the first phase, participants were interviewed using a baseline questionnaire. The second phase consisted of focus groups with 19 of the 100 participants in the quantitative phase. The scores obtained from the quantitative analysis are in line with the qualitative data; they reflect that grandparent carers who are more involved in the care of their grandchildren have more symptoms of depression and stress and have poorer perceptions of physical health-related quality of life. What may at first appear to be a positive aspect, keeping grandparent carers active, can become negative when it comes to shared care and when the grandparents' willingness to provide care is abused.

Prediabetes as a risk factor for all-cause and cause-specific mortality: a prospective analysis of 115,919 adults without diabetes in Mexico City.

BACKGROUND: Prediabetes has been associated with increased all-cause and cardiovascular mortality. However, no large-scale studies have been conducted in Mexico or Latin America examining these associations. METHODS: We analyzed data from 115,919 adults without diabetes (diagnosed or undiagnosed) aged 35-84 years who participated in the Mexico City Prospective Study between 1998 and 2004. Participants were followed until January 1st, 2021 for cause-specific mortality. We defined prediabetes according to the American Diabetes Association (ADA, HbA1c 5.7% to 6.4%) and the International Expert Committee (IEC, HbA1c 6.0-6.4%) definitions. Cox regression adjusted for confounders was used to estimate all-cause and cause-specific mortality rate ratios (RR) at ages 35-74 years associated with prediabetes. FINDINGS: During 2,085,392 person-years of follow-up (median in survivors 19 years), there were 6,810 deaths at ages 35-74, including 1,742 from cardiovascular disease, 892 from renal disease and 108 from acute diabetic crises. Of 110,405 participants aged 35-74 years at recruitment, 28,852 (26%) had ADA-defined prediabetes and 7,203 (7%) had IEC-defined prediabetes. Compared with those without prediabetes, individuals with prediabetes had higher risk of all-cause mortality at ages 35-74 years (RR 1.13, 95% CI 1.07-1.19 for ADA-defined prediabetes and RR 1.28, 1.18-1.39 for IEC-defined prediabetes), as well as increased risk of cardiovascular mortality (RR 1.22 [1.10-1.35] and 1.42 [1.22-1.65], respectively), renal mortality (RR 1.35 [1.08-1.68] and 1.69 [1.24-2.31], respectively), and death from an acute diabetic crisis (RR 2.63 [1.76-3.94] and 3.43 [2.09-5.62], respectively). RRs were larger at younger than at older ages, and similar for men compared to women. The absolute excess risk associated with ADA and IEC-defined prediabetes at ages 35-74 accounted for6% and 3% of cardiovascular deaths respectively, 10% and 5% of renal deaths respectively, and 31% and 14% of acute diabetic deaths respectively. INTERPRETATION: Prediabetes is a significant risk factor for all-cause, cardiovascular, renal, and acute diabetic deaths in Mexican adults. Identification and timely management of individuals with prediabetes for targeted risk reduction could contribute to reducing premature mortality from cardiometabolic causes in this population. FUNDING: Wellcome Trust, the Mexican Health Ministry, the National Council of Science and Technology for Mexico, Cancer Research UK, British Heart Foundation, UK Medical Research Council. Instituto Nacional de Geriatría (Mexico City).

Multiple juvenile xanthogranuloma.

Juvenile xanthogranuloma is the most frequent form of non-Langerhans cell histiocytosis in children. Clinically, it presents as well defined, yellowish papules that are typically located on the head, neck, upper trunk, and proximal region of the extremities. Although solitary lesions are the most common presentation, few cases of multiple juvenile xanthogranuloma have been described, more frequently associated with extracutaneous involvement. We report a 2-month-old girl with 22 cutaneous papules, clinically and histologically compatible with juvenile xanthogranulomas. Screening of visceral involvement was performed with no evidence of systemic disease. Identifying high-risk factors of systemic disease in patients with multiple juvenile xanthogranuloma is essential to perform an appropriate management of this entity.

Design and Evaluation of NSAID Derivatives as AKR1C3 Inhibitors for Breast Cancer Treatment through Computer-Aided Drug Design and In Vitro Analysis.

Breast cancer is a major global health issue, causing high incidence and mortality rates as well as psychological stress for patients. Chemotherapy resistance is a common challenge, and the Aldo-keto reductase family one-member C3 enzyme is associated with resistance to anthracyclines like doxorubicin. Recent studies have identified celecoxib as a potential treatment for breast cancer. Virtual screening was conducted using a quantitative structure-activity relationship model to develop similar drugs; this involved backpropagation of artificial neural networks and structure-based virtual screening. The screening revealed that the C-6 molecule had a higher affinity for the enzyme (-11.4 kcal/mol), a lower half-maximal inhibitory concentration value (1.7 µM), and a safer toxicological profile than celecoxib. The compound C-6 was synthesized with an 82% yield, and its biological activity was evaluated. The results showed that C-6 had a more substantial cytotoxic effect on MCF-7 cells (62%) compared to DOX (63%) and celecoxib (79.5%). Additionally, C-6 had a less harmful impact on healthy L929 cells than DOX and celecoxib. These findings suggest that C-6 has promising potential as a breast cancer treatment.

A Prospective, Observational Study of the Effect of a High-Calorie, High-Protein Oral Nutritional Supplement with HMB in an Old and Malnourished or at-Risk-of-Malnutrition Population with Hip Fractures: A FracNut Study.

BACKGROUND: Hip fractures are prevalent among older people, often leading to reduced mobility, muscle loss, and bone density decline. Malnutrition exacerbates the prognosis post surgery. This study aimed to evaluate the impact of a 12-week regimen of a high-calorie, high-protein oral supplement with ß-hydroxy-ß-methylbutyrate (HC-HP-HMB-ONS) on nutritional status, daily activities, and compliance in malnourished or at-risk older patients with hip fractures receiving standard care. SUBJECTS AND METHODS: A total of 270 subjects ≥75 years of age, residing at home or in nursing homes, malnourished or at risk of malnutrition, and post hip fracture surgery, received HC-HP-HMB-ONS for 12 weeks. Various scales and questionnaires assessed outcomes. RESULTS: During the 12 weeks of follow-up, 82.8% consumed ≥75% of HC-HP-HMB-ONS. By week 12, 62.4% gained or maintained weight (+0.3 kg), 29.2% achieved normal nutritional status (mean MNA score +2.8), and 46.8% improved nutritional status. Biochemical parameters improved significantly. Subjects reported good tolerability (mean score 8.5/10), with 87.1% of healthcare providers concurring. CONCLUSIONS: The administration of HC-HP-HMB-ONS markedly enhanced nutritional status and biochemical parameters in older hip-fracture patients, with high compliance and tolerability. Both patients and healthcare professionals expressed satisfaction with HC-HP-HMB-ONS.

Accumulation Dynamics of Defective Genomes during Experimental Evolution of Two Betacoronaviruses.

Virus-encoded replicases often generate aberrant RNA genomes, known as defective viral genomes (DVGs). When co-infected with a helper virus providing necessary proteins, DVGs can multiply and spread. While DVGs depend on the helper virus for propagation, they can in some cases disrupt infectious virus replication, impact immune responses, and affect viral persistence or evolution. Understanding the dynamics of DVGs alongside standard viral genomes during infection remains unclear. To address this, we conducted a long-term experimental evolution of two betacoronaviruses, the human coronavirus OC43 (HCoV-OC43) and the murine hepatitis virus (MHV), in cell culture at both high and low multiplicities of infection (MOI). We then performed RNA-seq at regular time intervals, reconstructed DVGs, and analyzed their accumulation dynamics. Our findings indicate that DVGs evolved to exhibit greater diversity and abundance, with deletions and insertions being the most common types. Notably, some high MOI deletions showed very limited temporary existence, while others became prevalent over time. We observed differences in DVG abundance between high and low MOI conditions in HCoV-OC43 samples. The size distribution of HCoV-OC43 genomes with deletions differed between high and low MOI passages. In low MOI lineages, short and long DVGs were the most common, with an additional cluster in high MOI lineages which became more prevalent along evolutionary time. MHV also showed variations in DVG size distribution at different MOI conditions, though they were less pronounced compared to HCoV-OC43, suggesting a more random distribution of DVG sizes. We identified hotspot regions for deletions that evolved at a high MOI, primarily within cistrons encoding structural and accessory proteins. In conclusion, our study illustrates the widespread formation of DVGs during betacoronavirus evolution, influenced by MOI and cell- and virus-specific factors.

Comparison of prevalence estimates of pfhrp2 and pfhrp3 deletions in Plasmodium falciparum determined by conventional PCR and multiplex qPCR and implications for surveillance and monitoring.

OBJECTIVES: The accuracy of malaria rapid diagnostic tests is threatened by Plasmodium falciparum with pfhrp2/3 deletions. This study compares gene deletion prevalence determined by multiplex real time polymerase chain reaction (qPCR) and conventional polymerase chain reaction (cPCR) using existing samples with clonality previously determined by microsatellite genotyping. METHODS: Multiplex qPCR was used to estimate prevalence of pfhrp2/3 deletions in three sets of previously collected patient samples from Eritrea and Peru. The qPCR was validated by multiplex digital polymerase chain reaction. Sample classification was compared with cPCR, and receiver operating characteristic curve analysis was used to determine the optimal ΔCq threshold that aligned the results of the two assays. RESULTS: qPCR classified 75% (637 of 849) of samples as single, and 212 as mixed-pfhrp2/3 genotypes, with a positive association between clonality and proportion of mixed-pfhrp2/3 genotype samples. The sample classification agreement between cPCR and qPCR was 75.1% (95% confidence interval [CI] 68.6-80.7%) and 47.8% (95% CI 38.9-56.9%) for monoclonal and polyclonal infections. The qPCR prevalence estimates of pfhrp2/3 deletions showed almost perfect (κ = 0.804, 95% CI 0.714-0.895) and substantial agreement (κ = 0.717, 95% CI 0.562-0.872) with cPCR for Peru and 2016 Eritrean samples, respectively. For 2019 Eritrean samples, the prevalence of double pfhrp2/3 deletions was approximately two-fold higher using qPCR. The optimal threshold for matching the assay results was ΔCq = 3. CONCLUSIONS: Multiplex qPCR and cPCR produce comparable estimates of gene deletion prevalence when monoclonal infections dominate; however, qPCR provides higher estimates where multi-clonal infections are common.

Adaptation and Validation of a Questionnaire to Measure Satisfaction With Telephone Care Among Individuals Living With Inflammatory Bowel Disease.

Background: Individuals with inflammatory bowel disease (IBD) require routine medical follow-up. The usage of telephone care (TC) appointments increased because of the coronavirus disease 2019 (COVID-19) pandemic. We aimed to adapt a questionnaire to evaluate satisfaction with TC use and validate it among IBD individuals. Methods: A committee of experts adapted the Telehealth Usability Questionnaire to the TC context and validated its use in individuals with IBD. This committee included three IBD gastroenterology care providers (GCPs), two IBD-patient partners, and two healthcare researchers. The committee evaluated the content validity of the adapted items to measure TC satisfaction. A pilot study assessed the readability and usability of the questionnaire. Individuals with IBD in Saskatchewan completed an online survey with the adapted questionnaire between December 2021 and April 2022. Data were analyzed using descriptive and correlational techniques. Psychometric analyses were conducted to examine the reliability and validity of the questionnaire. Results: The committee of experts developed the Telephone Care Satisfaction Questionnaire (TCSQ patient), with 16 items and one overall item for TC satisfaction. After the pilot, 87 IBD individuals participated in the online survey. A strong correlation was observed between the 16-item standardized level of TC satisfaction and the overall item, r = 0.85 (95%CI 0.78-0.90, p < 0.001). The TCSQ patient had optimal internal reliability (α = 0.96). Two dimensions were identified in the exploratory factor analysis (i.e., TC usefulness and convenience). Conclusion: The TCSQ patient is a valid and reliable measure of TC satisfaction among individuals with IBD. This questionnaire demonstrated excellent psychometric properties and we recommend its use.

Coronary Artery Embolism and Myocardial Infarction, case report.

Coronary embolism (CE) is a rare cause of non-atherosclerotic acute coronary syndrome (ACS). The clinical presentation is similar to ACS, and the diagnosis is supported by Shibata criteria. Atrial fibrillation is the main reported etiology in CE cases. Management includes percutaneous intervention with thromboaspiration and anticoagulation. The following case is a description of a patient with acute chest pain and recently diagnosed atrial fibrillation (AF) with a rapid ventricular response, is described. A thrombotic lesion in the distal right coronary artery (RCA) of embolic origin, was documented. Successful mechanical thromboaspiration was performed; intravascular ultrasound (IVUS) showed no thrombus, dissection, or atherosclerotic plaque. CE is an underdiagnosed cause of ACS; diagnosis relies on Shibata criteria, and patients experience worse outcomes in follow-up.

The pericapsular nerve group block, a highly selective blockage for intracapsular hip fractures: A case series.

Hip fracture is a very frequent clinical situation in the elderly and frail patient. The Pericapsular Nerve Group (PENG) has emerged as a highly selective block for the intracapsular hip fractures. We describe 44 patients with intracapsular hip fractures who underwent a PENG block in addition to spinal anaesthesia with. The main objective was to assess post-surgical pain control at the recovery room and after 24 h. Also, we considered the need for first of second analgesic rescue during the first 24 h after surgery. Only 10 patients presented mild pain at the recovery room. Up to 30 of them had pain after 24 h. However, 25 of these patients reported having mild pain. Only 9 patients required analgesic rescue for postoperative pain control. In conclusion, PENG block is a locoregional technique that allows good postoperative pain control and low opioid consumption during the postoperative period of intracapsular hip fractures.

Development of dye-sensitized solar cells using pigment extracts produced by Talaromyces atroroseus GH2.

The identification of more efficient, clean, secure, and competitive energy supply is necessary to align with the needs of sustainable devices. For this reason, a study for developing innovative dye-sensitized solar cells (DSSCs) based on microbial pigments is reported starting from Talaromyces atroroseus GH2. The fungus was cultivated by fermentation and the extracellular pigment extract was characterized by HPLC-DAD-ESI-MS analyses. The most abundant compound among the 22 azaphilone-type pigments identified was represented by PP-O. The device's behavior was investigated in relation to electrolyte and pH for verifying the stability on time and the photovoltaic performance. Devices obtained were characterized by UV-vis measurements to verify the absorbance intensity and transmittance percentage. Moreover, photovoltaic parameters through photo-electrochemical measurements (I-V curves) and impedance characteristics by Electrochemical Impedance Spectroscopy (EIS) were determined. The best microbial device showed a short-circuit current density (Jsc) of 0.69 mA/cm2, an open-circuit photo-voltage (Voc) of 0.27 V and a Fill Factor (FF) of 0.60. Furthermore, the power conversion efficiency (PCE) of the device was 0.11%. Thus, the present study demonstrated the potential of microbial origin pigments for developing DSSCs.

Uneven response of phytoplankton-bacteria coupling under Saharan dust pulse and ultraviolet radiation in the south-western Mediterranean Sea.

The microbial carbon (C) flux in the ocean is a key functional process governed by the excretion of organic carbon by phytoplankton (EOC) and heterotrophic bacterial carbon demand (BCD). Ultraviolet radiation (UVR) levels in upper mixed layers and increasing atmospheric dust deposition from arid regions may alter the degree of coupling in the phytoplankton-bacteria relationship (measured as BCD:EOC ratio) with consequences for the C-flux through these compartments in marine oligotrophic ecosystem. Firstly, we performed a field study across the south-western (SW) Mediterranean Sea to assess the degree of coupling (BCD:EOC) and how it may be related to metabolic balance (total primary production: community respiration; PPT:CR). Secondly, we conducted a microcosm experiment in two contrasting areas (heterotrophic nearshore and autotrophic open sea) to test the impact of UVR and dust interaction on microbial C flux. In the field study, we found that BCD was not satisfied by EOC (i.e., BCD:EOC >1; uncoupled phytoplankton-bacteria relationship). BCD:EOC ratio was negatively related to PPT:CR ratio across the SW Mediterranean Sea. A spatial pattern emerged, i.e. in autotrophic open sea stations uncoupling was less severe (BCD:EOC ranged 1-2), whereas heterotrophic nearshore stations uncoupling was more severe (BCD:EOC > 2). In the experimental study, in the seawater both enriched with dust and under UVR, BCD:EOC ratio decreased by stimulating autotrophic processes (particulate primary production (PPP) and EOC) in the heterotrophic nearshore area, whereas BCD:EOC increased by stimulating heterotrophic processes [heterotrophic bacterial production (HBP), bacterial growth efficiency (BGE), bacterial respiration (BR)] in the autotrophic open sea. Our results show that this spatial pattern could be reversed under future UVR × Dust scenario. Overall, the impact of greater dust deposition and higher UVR levels will alter the phytoplankton-bacteria C-flux with consequences for the productivity of both communities, their standing stocks, and ultimately, the ecosystem's metabolic balance at the sea surface.