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1.
Arch Ital Urol Androl ; 96(1): 12245, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38363230

RESUMO

To the Editor, Erectile dysfunction (ED) is one of the most prevalent conditions affecting men globally, with significant psychological and social consequences. The prevalence varies across different populations, and it is estimated around 50% in men aged between 40 to 70. The etiology of ED is multifactorial, involving a complex crosstalk between psychological, hormonal, neurogenic, vascular, and structural factors [...].


Assuntos
Disfunção Erétil , Masculino , Humanos , Adulto , Pessoa de Meia-Idade , Idoso , Disfunção Erétil/etiologia , Disfunção Erétil/terapia , Disfunção Erétil/epidemiologia , Ferro
2.
Medicina (Kaunas) ; 60(2)2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38399502

RESUMO

Urinary tract infections (UTIs) are the second most frequent type of infection observed in clinical practice. Gram-negative Enterobacteriaceae are common pathogens in UTIs. Excessive antibiotic use in humans and animals, poor infection control, and increased global travel have accelerated the spread of multidrug-resistant strains (MDR). Carbapenem antibiotics are commonly considered the last line of defense against MDR Gram-negative bacteria; however, their efficacy is now threatened by the increasing prevalence of carbapenem-resistant Enterobacteriaceae (CRE). This comprehensive review aims to explore the biological mechanisms underlying carbapenem resistance and to present a focus on therapeutic alternatives currently available for complicated UTIs (cUTIs). A comprehensive bibliographic search was conducted on the PubMed/MEDLINE, Scopus, and Web of Science databases in December 2023. The best evidence on the topic was selected, described, and discussed. Analyzed with particular interest were the clinical trials pivotal to the introduction of new pharmacological treatments in the management of complicated cUTIs. Additional suitable articles were collected by manually cross-referencing the bibliography of previously selected papers. This overview provides a current and comprehensive examination of the treatment options available for CRE infections, offering a valuable resource for understanding this constantly evolving public health challenge.


Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos , Infecções Urinárias , Humanos , Infecções Urinárias/microbiologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Carbapenêmicos/uso terapêutico , Farmacorresistência Bacteriana Múltipla
3.
Eur J Cancer Prev ; 33(2): 87-94, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38051582

RESUMO

OBJECTIVE: To evaluate the quality of apps for prostate cancer antigen (PSA) dosage, available for downloading on the iOS and Android platforms, discussing the potential role of mobile health applications (MHAs) in update the screening protocol. METHODS: An observational cross-sectional descriptive study of all smartphone apps for PSA dosage was performed through the most used platforms (iOS and Android). On 10 February 2023, a total of 457 apps were found according to the search criteria. Mobile Application Rating Scale (MARS) was adopted to assess apps' quality. Then, MARS items were analyzed through descriptive statistics and bivariate correlations between study variables with Pearson's coefficient. RESULTS: Of all samples, 24 MHAs were included in the final analysis: 12% (n = 3) from the iTunes App Store and 88% (n = 21) from the Google Play Store. According to the MARS quality assessment, the mean values 2.61, 2.94, 3.11, 2.97, 2.94, and 2.63 were measured for the engagement, functionality, aesthetics, information, overall mean score, and subjective quality, respectively. CONCLUSION: The MHAs for PSA were under the acceptability threshold and future improvements are required. Moreover, MHAs appropriately developed could play an active role in PSA screening campaign and adherence of follow-up regimens. Finally, the virtual instrument could both reduce the social divide of access to care for patients in rural areas and improve PCA detection, speeding up the active treatment.


Assuntos
Aplicativos Móveis , Neoplasias da Próstata , Telemedicina , Masculino , Humanos , Estudos Transversais , Antígeno Prostático Específico , Detecção Precoce de Câncer , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/epidemiologia
4.
Medicina (Kaunas) ; 59(11)2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-38004082

RESUMO

Background and Objectives: Despite advancements in the diagnosis and treatment of testicular germ cell tumours (TGTCs), challenges persist in identifying reliable biomarkers for early detection and precise disease management. This narrative review addresses the role of microRNAs (miRNAs) as potential diagnostic tools and therapeutic targets in the treatment of TGCTs. Materials and Methods: Three databases (PubMed®, Web of Science™, and Scopus®) were queried for studies investigating the utility of miRNA as diagnostic tools, assessing their prognostic significance, and evaluating their potential to guide TGCT treatment. Different combinations of the following keywords were used, according to a free-text protocol: "miRNA", "non-coding RNA", "small RNA", "Testicular Cancer", "seminomatous testicular germ cell", "non-seminomatous testicular germ cell". Results: The potential of miRNAs as possible biomarkers for a non-invasive diagnosis of TGCT is appealing. Their integration into the diagnostic pathway for TGCT patients holds the potential to enhance the discriminative power of conventional serum tumour markers (STMs) and could expedite early diagnosis, given that miRNA overexpression was observed in 50% of GCNIS cases. Among miRNAs, miR-371a-3p stands out with the most promising evidence, suggesting its relevance in the primary diagnosis of TGCT, particularly when conventional STMs offer limited value. Indeed, it demonstrated high specificity (90-99%) and sensitivity (84-89%), with good positive predictive value (97.2%) and negative predictive value (82.7%). Furthermore, a direct relationship between miRNA concentration, disease burden, and treatment response exists, regardless of disease stages. The initial evidence of miRNA decrease in response to surgical treatment and systemic chemotherapy has been further supported by more recent results suggesting the potential utility of this tool not only in evaluating treatment response but also in monitoring residual disease and predicting disease relapse. Conclusions: MiRNAs could represent a reliable tool for accurate diagnosis and disease monitoring in the treatment of TGCT, providing more precise tools for early detection and treatment stratification. Nevertheless, well-designed clinical trials and comprehensive long-term data are needed to ensure their translation into effective clinical tools.


Assuntos
MicroRNAs , Neoplasias Embrionárias de Células Germinativas , Neoplasias Testiculares , Masculino , Humanos , MicroRNAs/genética , Neoplasias Testiculares/diagnóstico , Neoplasias Testiculares/genética , Neoplasias Testiculares/patologia , Recidiva Local de Neoplasia , Neoplasias Embrionárias de Células Germinativas/diagnóstico , Neoplasias Embrionárias de Células Germinativas/genética , Biomarcadores Tumorais/genética
5.
Int J Impot Res ; 2023 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-37865715

RESUMO

Several previous studies on YouTubeTM information on medical topics have already been published. The current study aimed to evaluate the quality information of YouTubeTM videos on Phosphodiesterase 5 inhibitors (PDE5-is). A systematic search on YouTube™ was conducted using 30 keyword combinations. For each keyword's combination, the first 50 videos were recorded. The quality of videos on YouTube™ was assessed with Patient Education Materials Assessment Tool for audio-visual content (PEMAT A/V), DISCERN score and a specified created Misinformation tool. According to the selection criteria, 229 YouTube™ videos were suitable for the analyses. Videos were stratified according to the five main identified topics: sildenafil [n = 98; 42.79%] vs tadalafil [n = 50; 21.83%] vs vardenafil [n = 44;19.21%] vs avanafil [n = 17; 7.42%] vs PDE5-is in general [n = 20; 8.73%]. The median overall PEMAT A/V Understandability score and Actionability score were 55% (interquartile range [IQR]: 42-75) and 0% (IQR = 0-67), respectively. Specifically, according to our stratification, YouTube Videos on avanafil reached higher values of both Understandability and Actionability (72.7% and 66.7, respectively) in contrast to other categories. According to DISCERN tool, the total overall median score was 29.5 (IQR = 18-41). According to Misinformation scale, the item 1 ('sexual stimulation') harboured an overall median score of 2 (IQR = 1-2); the item 2 ('side effects') an overall median score of 2 (IQR = 1-3); the item 3 ('treatment choices') an overall median score of 1 (IQR = 1-2); the item 4 ('contraindications') an overall median score of 2 (IQR = 1-2). YouTube™ is a fast and open-access source for mass information. The overall quality of the PDE5-is contents provided is sadly unsatisfactory. Nowadays, YouTube™ cannot be recommended as a reliable source of information on PDE5-is.

6.
Arch Ital Urol Androl ; 95(2): 11350, 2023 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-37254932

RESUMO

To the Editor, In 1998 Sildenafil was approved by the Food and Drug Administration as first line therapy for erectile dysfunction. Since then, phosphodiesterase type 5 inhibitors (PDE5i) represent the first-line treatment of erectile dysfunction (ED), improving physiological erectile function, sexual orgasmic function, psychological self-esteem, couples' relationship, and quality of life. [...].


Assuntos
Disfunção Erétil , Inibidores da Fosfodiesterase 5 , Citrato de Sildenafila , Disfunção Erétil/tratamento farmacológico , Disfunção Erétil/psicologia , Humanos , Masculino , Inibidores da Fosfodiesterase 5/uso terapêutico , Citrato de Sildenafila/uso terapêutico , Qualidade de Vida
7.
Medicina (Kaunas) ; 59(3)2023 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-36984626

RESUMO

Background and Objectives: To describe the predictors of cribriform variant status and perineural invasion (PNI) in robot-assisted radical prostatectomy (RARP) histology. To define the rates of upgrading between biopsy specimens and final histology and their possible predictive factors in prostate cancer (PCa) patients undergoing RARP. Material and Methods: Within our institutional database, 265 PCa patients who underwent prostate biopsies and consecutive RARP at our center were enrolled (2018-2022). In the overall population, two independent multivariable logistic regression models (LRMs) predicting the presence of PNI or cribriform variant status at RARP were performed. In low- and intermediate-risk PCa patients according to D'Amico risk classification, three independent multivariable LRMs were fitted to predict upgrading. Results: Of all, 30.9% were low-risk, 18.9% were intermediate-risk and 50.2% were high-risk PCa patients. In the overall population, the rates of the cribriform variant and PNI at RARP were 55.8% and 71.1%, respectively. After multivariable LRMs predicting PNI, total tumor length in biopsy cores (>24 mm [OR: 2.37, p-value = 0.03], relative to <24 mm) was an independent predictor. After multivariable LRMs predicting cribriform variant status, PIRADS (3 [OR:15.37], 4 [OR: 13.57] or 5 [OR: 16.51] relative to PIRADS 2, all p = 0.01) and total tumor length in biopsy cores (>24 mm [OR: 2.47, p = 0.01], relative to <24 mm) were independent predicting factors. In low- and intermediate-risk PCa patients, the rate of upgrading was 74.4% and 78.0%, respectively. After multivariable LRMs predicting upgrading, PIRADS (PIRADS 3 [OR: 7.01], 4 [OR: 16.98] or 5 [OR: 20.96] relative to PIRADS 2, all p = 0.01) was an independent predicting factor. Conclusions: RARP represents a tailored and risk-adapted treatment strategy for PCa patients. The indication of RP progressively migrates to high-risk PCa after a pre-operative assessment. Specifically, the PIRADS score at mpMRI should guide the decision-making process of urologists for PCa patients.


Assuntos
Imageamento por Ressonância Magnética Multiparamétrica , Neoplasias da Próstata , Robótica , Masculino , Humanos , Próstata/cirurgia , Próstata/patologia , Incidência , Centros de Atenção Terciária , Prostatectomia/métodos , Neoplasias da Próstata/epidemiologia , Neoplasias da Próstata/cirurgia , Neoplasias da Próstata/patologia , Estudos Retrospectivos , Gradação de Tumores
8.
Arch Ital Urol Androl ; 95(1): 11236, 2023 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-36924366

RESUMO

Sexual health impairment is one of the most important issues worldwide, with an increasing number of men and women affected. Specifically in male sexual dysfunction (SD), several risk factors were established such as atherosclerosis, hypertension, diabetes mellitus, smoking or obesity. The co-presence of more than one of risk factors identifies a condition, defined as the metabolic syndrome (MetS), related directly to the SD. However, not all the physicians involved in the MetS management routinely discussed the sexual impairment, increasing the bothering feelings of patients. Furthermore, the lack of knowledge, insufficient time, lack of attention, ambiguities about responsibility, insufficient training and experience, shared among physicians, regarding the communication and treatment of sexual dysfunction, are all reported factors involved in under-valuation of SD. The current paper represents a warning to the experts, with the aim of increasing the awareness of SD among clinicians and to promote the education, training and collaboration with sex therapists, through a multidisciplinary team, that can lead to a holistic approach in SD assessment and treatment.


Assuntos
Médicos , Disfunções Sexuais Fisiológicas , Humanos , Masculino , Feminino , Disfunções Sexuais Fisiológicas/etiologia , Disfunções Sexuais Fisiológicas/terapia , Fatores de Risco , Comportamento Sexual , Obesidade/complicações
9.
Medicina (Kaunas) ; 58(11)2022 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-36363477

RESUMO

Background and Objective: Blood loss represents a long-standing concern of radical prostatectomy (RP). This study aimed to assess how red line cell values changed following robot-assisted radical prostatectomy (RARP) for prostate cancer (PCa). Materials and Methods: The blood panels of 453 consecutive PCa patients undergoing RARP at a single tertiary academic referral center, from September 2020 to April 2022, were reviewed. Data from 363 patients with the blood panel available for the following timeframe: within seven days before surgery, six hours after surgery, and the first three postoperative days, were analyzed. Specifically, hemoglobin (Hb, g/dL), red blood cells (RBCs, ×106/µL), and hematocrit (HCT, %) trends were collected. Results: Considering the Hb trend, the median values in the preoperative day, postoperative day (POD) 2, and POD 3 are 14.7 (interquartile range (IQR) = 13.9−15.4), 12.1 (IQR = 11.2−12.9), and 12.2 (IQR = 11.2−13.1), respectively. The ∆ between preoperative day and POD 2 is 2.5 (IQR = 1.8−3.2) (p < 0.001). Considering the RBCs trend, the median values in the preoperative day, POD 2, and POD 3 are 4.9 (IQR = 4.7−5.3), 4.1 (IQR = 3.8−4.4), and 4.1 (IQR = 3.8−4.5), respectively. The ∆ between preoperative day and POD 2 is 0.9 (IQR = 0.6−1.1) (p < 0.001). Considering the HCT trend, the median values in the preoperative day, POD 2, and POD 3 are 44.4 (IQR = 41.7−46.6), 36.4 (IQR = 33.8−38.9), and 36.1 (IQR = 33.5−38.7), respectively. The ∆ between preoperative day and POD 2 is 7.8 (IQR = 5.2−10.5) (p < 0.001). Conclusions: Overall, patients undergoing RARP experience a significant, but clinically limited, decline in red line cell values between the preoperative time and the second day post-surgery. These observations are important to provide physicians with knowledge of the expected postoperative course and, thus, to improve the quality of patient care.


Assuntos
Neoplasias da Próstata , Procedimentos Cirúrgicos Robóticos , Robótica , Masculino , Humanos , Resultado do Tratamento , Prostatectomia , Neoplasias da Próstata/cirurgia , Eritrócitos , Linhagem Celular
10.
Arch Ital Urol Androl ; 94(3): 285-290, 2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36165471

RESUMO

OBJECTIVES: To assess YouTube™ videos' quality on prostate checks, especially on the digital rectal exam (DRE), and to investigate if they can inform patients correctly and eradicate their beliefs and myths. METHODS: A search using as keywords "digital rectal exam for prostate cancer" was performed on the YouTubeTM platform. We selected the first 100 videos. To assess video quality content, Patient Education Materials Assessment Tool for audio-visual content (PEMAT A/V) and Misinformation tool were used. RESULTS: Seventy-three videos were suitable for the analyses. The median PEMAT A/V Understandability score and PEMAT A/V Actionability score were 46.2% (interquartile range [IQR]: 30.8-76.9) and 50.0% (IQR: 25.0-75.0), respectively. The medi-an PEMAT A/V Understandability and Actionability scores were 69.2% (IQR: 46.2-88.5) vs 46.2% (IQR: 30.8-61.5) (p = 0.01) and 100.0% (IQR: 87.5-100.0) vs 25.0% (IQR: 25.0-68.8) (p < 0.001), for healthcare workers vs patients, respectively. According to the Misinformation tool, the median misinforma-tion score of the overall videos was 2.2 (IQR:1.7-2.8). According to the target audience, the misinformation score was 2.8 (IQR: 2.4-3.5) vs 2.0 (IQR: 1.5-2.8) (p = 0.02), for healthcare workers vs patients, respectively. CONCLUSIONS: Currently, based on our analyses, YouTubeTM videos' quality on DRE resulted unsatisfactory according to the PEMAT A/V score and the Misinformation tool. Videos targeted to healthcare workers got higher quality scores if compared to videos targeted to patients. Therefore, YouTubeTM videos' may not be considered a reliable source of information on DRE for patients.


Assuntos
Promoção da Saúde , Próstata , Mídias Sociais , Humanos , Masculino , Educação de Pacientes como Assunto
11.
Ann Vasc Surg ; 82: 41-46, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34902476

RESUMO

BACKGROUND: Severe carotid stenosis (CS) is a major risk factor for stroke. Carotid Endarterectomy (CEA) is the gold standard revascularization technique of CS while carotid artery stenting (CAS) is considered an alternative treatment option, especially in high-risk patients or those with relative contraindications to CEA. The aim of this study was to evaluate the results of CEA and CAS with Roadsaver® stent device. METHODS: We made a retrospective analysis of 119 patients undergoing treatment of CS. All CS were evaluated with imaging exams. The patients were divided into CEA group and CAS group. As primary endpoints of the study overall and cardiovascular cause - related mortality, freedom from stroke, and restenosis were considered. All patients were followed up and revaluated with duplex scan over a minimum of 6 months and a maximum of 36 months (follow-up mean time 22.3 ± 3.4 months). RESULTS: In the whole cohort 86 of 119 patients underwent CEA and 33 of 119 CAS. Risk factors were superposable in both groups. During follow-up, we observed 4 deaths, 2 cardiovascular events and 12 restenosis. CEA was associated with lower death probability than CAS (P = 0.036). Probability of Restenosis and cardiovascular events did not vary between CAS and CEA groups. CONCLUSIONS: Albeit CEA remains the gold standard for the treatment of severe CS, CAS with new double layer micromesh stent can be considered a useful and safe alternative in some clinical conditions.


Assuntos
Estenose das Carótidas , Endarterectomia das Carótidas , Acidente Vascular Cerebral , Artérias Carótidas , Estenose das Carótidas/diagnóstico por imagem , Estenose das Carótidas/cirurgia , Endarterectomia das Carótidas/efeitos adversos , Humanos , Estimativa de Kaplan-Meier , Recidiva , Estudos Retrospectivos , Fatores de Risco , Stents/efeitos adversos , Acidente Vascular Cerebral/etiologia , Fatores de Tempo , Resultado do Tratamento
12.
Vaccines (Basel) ; 11(1)2022 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-36679937

RESUMO

BACKGROUND: YouTubeTM is an open-access source for mass information. Several previous studies of YouTubeTM videos showed a high rate of misinformation in the urological field. The aim of the current study was to evaluate the quality of information on immunotherapy (IMT) for urological tumors uploaded to YouTubeTM. METHODS: YouTubeTM videos were searched using nine keyword combinations. The PEMAT, the DISCERN tool, and the Misinformation scale were used to assess the quality of information in YouTubeTM videos about IMT for urological tumors. Descriptive statistics and Kruskal-Wallis, Chi-square, proportion, and Pearson's tests were performed. RESULTS: According to the selection criteria, 156 YouTubeTM videos were suitable for the analysis and stratified according to topic (urothelial carcinoma vs. renal cell cancer vs. prostate cancer vs. general information on IMT). According to PEMAT A/V, the overall Understandability score was 40% (Inter-Quartile Range [IQR]: 20-61.5) and the overall Actionability score was 0% (IQR: 0-25). According to the DISCERN tool, the overall DISCERN score was 44 (IQR: 39-53.2), defined as "fair". According to the Misinformation scale, we recorded the lowest median overall score for item 4 ("IMT in multimodality approach") and item 5 ("Future perspective"). CONCLUSIONS: YouTubeTM cannot be recommended as a reliable source of information on IMT for urological malignancies. In addition, YouTubeTM videos contributed to the spread of misinformation by underestimating the role of IMT in a multimodality approach and missing the findings of published clinical trial results.

13.
Sci Rep ; 11(1): 21009, 2021 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-34697338

RESUMO

We have designed a set of experiments to test the role of borosilicate reactor on the yielding of the Miller-Urey type of experiment. Two experiments were performed in borosilicate flasks, two in a Teflon flask and the third couple in a Teflon flask with pieces of borosilicate submerged in the water. The experiments were performed in CH4, N2, and NH3 atmosphere either buffered at pH 8.7 with NH4Cl or unbuffered solutions at pH ca. 11, at room temperature. The Gas Chromatography-Mass Spectroscopy results show important differences in the yields, the number of products, and molecular weight. In particular, a dipeptide, multi-carbon dicarboxylic acids, PAHs, and a complete panel of biological nucleobases form more efficiently or exclusively in the borosilicate vessel. Our results offer a better explanation of the famous Miller's experiment showing the efficiency of borosilicate in a triphasic system including water and the reduced Miller-Urey atmosphere.

14.
Life (Basel) ; 11(8)2021 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-34440544

RESUMO

Template-free nonenzymatic polymerization of 3',5' cyclic nucleotides is an emerging topic of the origin of life research. In the last ten years, a number of papers have been published addressing various aspects of this process. These works evoked a vivid discussion among scientists working in the field of prebiotic chemistry. The aim of the current review is to answer the most frequently raised questions related to the detection and characterization of oligomeric products as well as to the geological context of this chemistry.

15.
Int J Mol Sci ; 22(2)2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33477625

RESUMO

The goal of prebiotic chemistry is the depiction of molecular evolution events preceding the emergence of life on Earth or elsewhere in the cosmos. Plausible experimental models require geochemical scenarios and robust chemistry. Today we know that the chemical and physical conditions for life to flourish on Earth were at work much earlier than thought, i.e., earlier than 4.4 billion years ago. In recent years, a geochemical model for the first five hundred million years of the history of our planet has been devised that would work as a cradle for life. Serpentinization processes in the Hadean eon affording self-assembled structures and vesicles provides the link between the catalytic properties of the inorganic environment and the impressive chemical potential of formamide to produce complete panels of organic molecules relevant in pre-genetic and pre-metabolic processes. Based on an interdisciplinary approach, we propose basic transformations connecting geochemistry to the chemistry of formamide, and we hint at the possible extension of this perspective to other worlds.


Assuntos
Evolução Química , Formamidas/química , Origem da Vida , Catálise , Química Orgânica , Planeta Terra
16.
Chemistry ; 26(65): 14919-14928, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-32846019

RESUMO

Formation and structural modification of oxygenated polycyclic aromatic hydrocarbons (oxyPAHs) by UV irradiation on minerals have recently been proposed as a possible channel of PAH transformation in astrochemical and prebiotic scenarios of possible relevance for the origin of life. Herein, it is demonstrated that high-energy proton-beam irradiation in the presence of various meteorites, including stony iron, achondrite, and chondrite types, promotes the conversion of two representative oxyPAH compounds, 1-naphthol and 1,8-dihydroxynaphthalene, to complex mixtures of oxygenated and oligomeric derivatives. The main identified products include polyhydroxy derivatives, isomeric dimers encompassing benzofuran and benzopyran scaffolds, and, notably, a range of quinones and perylene derivatives. Addition of urea, a prebiotically relevant chemical precursor, expanded the range of identified species to include, among others, quinone diimines. Proton-beam irradiation of oxyPAH modulated by nitrogen-containing compounds such as urea is proposed as a possible contributory mechanism for the formation and processing of insoluble organic matter in meteorites and in prebiotic processes.

17.
Astrobiology ; 19(9): 1117-1122, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31045430

RESUMO

In this work, we provide an answer to the question formulated by Albert Eschenmoser: "How would you envisage the bridge between potentially primordial geochemistry that had been disordered and one that gradually became self-organizing?" Analysis of the free-energy profiles of some of the key reactions leading to formation of nucleotides and their oligomers shows that, whereas the first part of the pathway, up to nucleotides, is energy-driven, in the second low-energy part entropic control in the form of structural compatibility becomes more important. We suggest that the birth of modern metabolism requires structural compatibility, which is enabled by the commensurability of the thermodynamics of the synthetic steps with the stabilizing effect of those intermolecular interactions that play a key role in dictating entropic control of these reactions.


Assuntos
Evolução Molecular , Cristalização , Origem da Vida , Termodinâmica
18.
Sci Rep ; 9(1): 4649, 2019 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-30862838

RESUMO

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

19.
Chemistry ; 25(13): 3181-3189, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30230056

RESUMO

The condensation of formamide has been shown to be a robust chemical pathway affording molecules necessary for the origin of life. It has been experimentally demonstrated that condensation reactions of formamide are catalyzed by a number of minerals, including silicates, phosphates, sulfides, zirconia, and borates, and by cosmic dusts and meteorites. However, a critical discussion of the catalytic power of the tested minerals, and the geochemical conditions under which the condensation would occur, is still missing. We show here that mineral self-assembled structures forming under alkaline silica-rich solutions are excellent catalysts for the condensation of formamide with respect to other minerals. We also propose that these structures were likely forming as early as 4.4 billion years ago when the whole earth surface was a reactor, a global scale factory, releasing large amounts of organic compounds. Our experimental results suggest that the conditions required for the synthesis of the molecular bricks from which life self-assembles, rather than being local and bizarre, appears to be universal and geologically rather conventional.

20.
Life (Basel) ; 8(2)2018 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-29925796

RESUMO

Molecular Darwinian evolution is an intrinsic property of reacting pools of molecules resulting in the adaptation of the system to changing conditions. It has no a priori aim. From the point of view of the origin of life, Darwinian selection behavior, when spontaneously emerging in the ensembles of molecules composing prebiotic pools, initiates subsequent evolution of increasingly complex and innovative chemical information. On the conservation side, it is a posteriori observed that numerous biological processes are based on prebiotically promptly made compounds, as proposed by the concept of Chemomimesis. Molecular Darwinian evolution and Chemomimesis are principles acting in balanced cooperation in the frame of Systems Chemistry. The one-pot synthesis of nucleosides in radical chemistry conditions is possibly a telling example of the operation of these principles. Other indications of similar cases of molecular evolution can be found among biogenic processes.

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