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1.
Endocr Regul ; 58(1): 83-90, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-38656255

RESUMEN

Objective. Abnormal lipid profile and obesity increase the risk of polycystic ovary syndrome (PCOS). PCOS patients may have a greater risk of infertility, metabolic syndrome (MetS) and cardiovascular disease (CVD) due to abnormal lipid profile and obesity. The aim of the study was to find the association between abnormal lipid profile and obesity in patients with PCOS. Methods. In this case-control study, a total of 102 female subjects (51 diagnosed PCOS and 51 age-matched healthy controls) were enrolled, aged between 20-40 years. Biochemical parameters such as total cholesterol (TC), triglycerides (TG), low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), very low-density lipoprotein-cholesterol (VLDL-C), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were estimated. Anthropometric parameters such as body mass index (BMI), waist circumference (WC), hip circumference (HC), and waist-to-hip ratio (WHR) were recorded. A p<0.05 was considered statistically significant. Results. Mean of BMI, WC, WHR, LH, FSH, TC, TG, LDL-C, and VLDL-C was found significantly elevated in patients with PCOS as compared to controls (p<0.01). However, the mean of HDL-C was found significantly reduced in patients with PCOS as compared to controls (p<0.01). BMI has shown a significant positive correlation with WC (r=0.562, p<0.01) and WHR (r=0.580, p<0.01) among PCOS patients. LH has shown a significant positive correlation with FSH (r=0.572, p<0.01) among PCOS patients. TC has shown a significant positive correlation with TG (r=0.687, p<0.01), LDL-C (r=0.917, p<0.01), and VLDL-C (r=0.726, p<0.01) among PCOS patients. Conclusion. The results showed that abnormal lipid profile and obesity have a significant association with PCOS patients. Regular monitoring and treatment of PCOS patients are required to reduce the risk of infertility, MetS, and CVD.


Asunto(s)
Índice de Masa Corporal , Lípidos , Obesidad , Síndrome del Ovario Poliquístico , Humanos , Síndrome del Ovario Poliquístico/sangre , Síndrome del Ovario Poliquístico/complicaciones , Femenino , Adulto , Estudios de Casos y Controles , Adulto Joven , Obesidad/sangre , Obesidad/complicaciones , Lípidos/sangre , Circunferencia de la Cintura , Triglicéridos/sangre , Hormona Luteinizante/sangre , Relación Cintura-Cadera , Hormona Folículo Estimulante/sangre , LDL-Colesterol/sangre
2.
Proc Natl Acad Sci U S A ; 115(37): E8765-E8774, 2018 09 11.
Artículo en Inglés | MEDLINE | ID: mdl-30150378

RESUMEN

Huntington disease (HD) is an autosomal dominant neurodegenerative disorder caused by expanded CAG repeats in the huntingtin gene (HTT). Although mutant HTT is expressed during embryonic development and throughout life, clinical HD usually manifests later in adulthood. A number of studies document neurodevelopmental changes associated with mutant HTT, but whether these are reversible under therapy remains unclear. Here, we identify very early behavioral, molecular, and cellular changes in preweaning transgenic HD rats and mice. Reduced ultrasonic vocalization, loss of prepulse inhibition, and increased risk taking are accompanied by disturbances of dopaminergic regulation in vivo, reduced neuronal differentiation capacity in subventricular zone stem/progenitor cells, and impaired neuronal and oligodendrocyte differentiation of mouse embryo-derived neural stem cells in vitro. Interventional treatment of this early phenotype with the histone deacetylase inhibitor (HDACi) LBH589 led to significant improvement in behavioral changes and markers of dopaminergic neurotransmission and complete reversal of aberrant neuronal differentiation in vitro and in vivo. Our data support the notion that neurodevelopmental changes contribute to the prodromal phase of HD and that early, presymptomatic intervention using HDACi may represent a promising novel treatment approach for HD.


Asunto(s)
Diferenciación Celular/efectos de los fármacos , Enfermedad de Huntington/fisiopatología , Ácidos Hidroxámicos/farmacología , Indoles/farmacología , Neuronas/efectos de los fármacos , Animales , Animales Modificados Genéticamente , Diferenciación Celular/genética , Diferenciación Celular/fisiología , Modelos Animales de Enfermedad , Femenino , Inhibidores de Histona Desacetilasas/farmacología , Humanos , Proteína Huntingtina/genética , Enfermedad de Huntington/genética , Ventrículos Laterales/patología , Masculino , Ratones Transgénicos , Mutación , Neuronas/metabolismo , Neuronas/fisiología , Panobinostat , Ratas
3.
Anal Chem ; 92(14): 10042-10047, 2020 07 21.
Artículo en Inglés | MEDLINE | ID: mdl-32551513

RESUMEN

Chiral discrimination is of crucial importance for many applications, including drug cross checking and electronic tongue-type devices. In a typical sensing scheme, an enantiomeric selector is combined with an appropriate transduction mechanism. We propose here a hybrid material composed of an electrically conducting oligomer i.e. oligo-(3,3'-dibenzothiophene) bearing inherently chiral features and polypyrrole as a support, which can undergo electrochemical actuation. The combination of both leads to a freestanding film that is addressable in a wireless way based on the principle of bipolar electrochemistry. The induced redox reactions lead to well-pronounced actuation when DOPA with the right chirality is present in solution as a model analyte, whereas absolutely no electromechanical response is measured for the wrong enantiomer. This constitutes a straightforward and absolute read out of chiral information where the amplitude of actuation is correlated with the concentration of the analyte. Optimization of the scheme results in highly efficient bending and thus opens up new directions in the field of chiral technologies.


Asunto(s)
Técnicas Electroquímicas , Polímeros/química , Pirroles/química , Tiofenos/química , Conductividad Eléctrica , Técnicas Electroquímicas/instrumentación , Conformación Molecular , Tiofenos/síntesis química
4.
Chemphyschem ; 20(7): 941-945, 2019 04 02.
Artículo en Inglés | MEDLINE | ID: mdl-30840350

RESUMEN

Combining the actuation of conducting polymers with additional functionalities is an interesting fundamental scientific challenge and increases their application potential. Herein we demonstrate the possibility of direct integration of a miniaturized light emitting diode (LED) in a polypyrrole (PPy) matrix in order to achieve simultaneous wireless actuation and light emission. A light emitting diode is used as a part of an electroactive surface on which electrochemical polymerization allows direct incorporation of the electronic device into the polymer. The resulting free-standing polymer/LED hybrid can be addressed by bipolar electrochemistry to trigger simultaneously oxidation and reduction reactions at its opposite extremities, leading to a controlled deformation and an electron flow through the integrated LED. Such a dual response in the form of actuation and light emission opens up interesting perspectives in the field of microrobotics.

5.
J Am Chem Soc ; 140(45): 15501-15506, 2018 11 14.
Artículo en Inglés | MEDLINE | ID: mdl-30347149

RESUMEN

Collecting electrochemical information concerning the presence of molecules in a solution is usually achieved by measuring current, potential, resistance, or impedance via connection to a power supply. Here, we suggest wireless electromechanical actuation as a straightforward readout of chemical information. This can be achieved based on the concept of bipolar electrochemistry, which allows measuring the presence of different model species in a quantitative way. We validate the concept by using a free-standing polypyrrole film. Its positively polarized extremity participates in an oxidation of the analyte and delivers electrons to the opposite extremity for the reduction of the polymer. This reduction is accompanied by the insertion of counterions and thus leads to partial swelling of the film, inducing its bending. The resulting actuation is found to be a linear function of the analyte concentration, and also a Michaelis-Menten type correlation is obtained for biochemical analytes. This electromechanical transduction allows an easy optical readout and opens up very interesting perspectives not only in the field of sensing but also far beyond, such as for the elaboration of self-regulating biomimetic systems.

6.
Angew Chem Int Ed Engl ; 56(45): 14183-14186, 2017 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-28914480

RESUMEN

Electrochemical actuation of conducting polymers usually requires a direct connection to an electric power supply. In this contribution, we suggest to overcome this issue by using the concept of bipolar electrochemistry. This allows changing the oxidation state of the polymer in a gradual and wireless way. Free-standing polypyrrole films were synthesized with an intrinsic morphological asymmetry of their two faces in order to form a bilayer structure. Immersing such objects in an electrolyte solution and exposing them to a potential gradient leads to the asymmetric oxidation/reduction of the polymer, resulting in differential shrinking and swelling along the main axis. This additional asymmetry is responsible for a structural deformation. Optimization allowed highly efficient bending, which is expected to open up completely new directions in the field of actuation due to the wireless mode of action.

7.
Indian J Exp Biol ; 51(7): 548-55, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23898554

RESUMEN

Black gram plants subjected to varying levels of Zn supply (0.01 to 10 microM Zn) showed optimum growth and dry matter yield in plants receiving 1 microM Zn. The dry matter yield of plants decreased in plants receiving 0.01 and 0.1 microM Zn (deficient) and excess levels of Zn (2 and 10 microM Zn). The plants grown with Zn deficient supply showed delayed flowering, premature bud abscission, reduced size of anthers, pollen producing capacity, pollen viability and stigma receptivity resulting in poor pod formation and seed yield. Providing Zn as a foliar spray at pre-flowering stage minimized the severity of Zn deficiency on reproductive structure development and enhanced the seed nutritional status by enhancing seed Zn density, seed carbohydrate (sugar and starch content) and storage proteins (albumins, globulins, glutenins, and prolamines).


Asunto(s)
Fabaceae/efectos de los fármacos , Flores/efectos de los fármacos , Germinación/efectos de los fármacos , Hojas de la Planta/efectos de los fármacos , Semillas/efectos de los fármacos , Zinc/administración & dosificación , Fabaceae/crecimiento & desarrollo , Flores/crecimiento & desarrollo , Flores/metabolismo , Hojas de la Planta/crecimiento & desarrollo , Polen/efectos de los fármacos , Polen/metabolismo , Semillas/crecimiento & desarrollo , Zinc/farmacología
8.
Cureus ; 15(10): e47162, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38022083

RESUMEN

This review aimed to comprehensively assess the association between tobacco use and oral health outcomes, specifically the presence of premalignant lesions (PMLs), through a synthesis of multiple assessments conducted in diverse populations. A systematic search of relevant literature was performed, and studies meeting the inclusion criteria were selected using appropriate Medical Subject Headings (MeSH) words and Boolean operators. Data from these studies was pooled and analysed using Review Manager 5.4 (The Cochrane Collaboration, The Nordic Cochrane Centre, Copenhagen). The Newcastle-Ottawa scale was used to assess the methodological quality of the studies included. The pooled analysis of the five selected papers revealed a significant correlation between tobacco use and an increased prevalence of PMLs among tobacco users. Tobacco users had an odds ratio of 15.22 (95% CI: 10.01-23.15) as compared to non-user cohorts, significant at p 0.0001. This comprehensive synthesis of assessments underscores the detrimental impact of tobacco use on oral health, particularly in terms of potentially malignant lesions. The findings emphasise the urgency of targeted public health interventions to address tobacco consumption and promote oral health awareness, especially in populations with high tobacco consumption rates. Standardisation of methodologies and representation of diverse populations in future research would strengthen the evidence base and facilitate more effective strategies to improve oral health outcomes globally.

9.
Adv Colloid Interface Sci ; 318: 102967, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37523999

RESUMEN

Establishing green and reliable energy resources is very important to counteract the carbon footprints and negative impact of non-renewable energy resources. Metal-organic frameworks (MOFs) are a class of porous material finding numerous applications due to their exceptional qualities, such as high surface area, low density, superior structural flexibility, and stability. Recently, increased attention has been paid to surface mounted MOFs (SURMOFs), which is nothing but thin film of MOF, as a new category in nanotechnology having unique properties compared to bulk MOFs. With the advancement of material growth and synthesis technologies, the fine tunability of film thickness, consistency, size, and geometry with a wide range of MOF complexes is possible. In this review, we recapitulate various synthesis approaches of SURMOFs including epitaxial synthesis approach, direct solvothermal method, Langmuir-Blodgett LBL deposition, Inkjet printing technique and others and then correlated the synthesis-structure-property relationship in terms of energy storage and conversion applications. Further the critical assessment and current problems of SURMOFs have been briefly discussed to explore the future opportunities in SURMOFs for energy storage and conversion applications.

10.
Sci Rep ; 13(1): 5019, 2023 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-36977815

RESUMEN

Several in-situ electrochemical approaches have been developed for performing a localized photoelectrochemical investigation of the photoanode. One of the techniques is scanning electrochemical microscopy (SECM), which probes local heterogeneous reaction kinetics and fluxes of generated species. In traditional SECM analysis of photocatalysts, evaluation of the influence of radiation on the rate of studied reaction requires an additional dark background experiment. Here, using SECM and an inverted optical microscope, we demonstrate the determination of O2 flux caused by light-driven photoelectrocatalytic water splitting. Photocatalytic signal and dark background are recorded in a single SECM image. We used an indium tin oxide electrode modified with hematite (α-Fe2O3) by electrodeposition as a model sample. The light-driven flux of oxygen is calculated by analysis of SECM image recorded in substrate generation/tip collection mode. In photoelectrochemistry, the qualitative and quantitative knowledge of oxygen evolution will open new doors for understanding the local effects of dopants and hole scavengers in a straightforward and conventional manner.

11.
Sci Rep ; 13(1): 22741, 2023 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-38123583

RESUMEN

Microbial electrosynthesis (MES) presents a versatile approach for efficiently converting carbon dioxide (CO2) into valuable products. However, poor electron uptake by the microorganisms from the cathode severely limits the performance of MES. In this study, a graphitic carbon nitride (g-C3N4)-metal-organic framework (MOF) i.e. HKUST-1 composite was newly designed and synthesized as the cathode catalyst for MES operations. The physiochemical analysis such as X-ray diffraction, scanning electron microscopy (SEM), and X-ray fluorescence spectroscopy showed the successful synthesis of g-C3N4-HKUST-1, whereas electrochemical assessments revealed its enhanced kinetics for redox reactions. The g-C3N4-HKUST-1 composite displayed excellent biocompatibility to develop electroactive biohybrid catalyst for CO2 reduction. The MES with g-C3N4-HKUST-1 biohybrid demonstrated an excellent current uptake of 1.7 mA/cm2, which was noted higher as compared to the MES using g-C3N4 biohybrid (1.1 mA/cm2). Both the MESs could convert CO2 into acetic and isobutyric acid with a significantly higher yield of 0.46 g/L.d and 0.14 g/L.d respectively in MES with g-C3N4-HKUST-1 biohybrid and 0.27 g/L.d and 0.06 g/L.d, respectively in MES with g-C3N4 biohybrid. The findings of this study suggest that g-C3N4-HKUST-1 is a highly efficient catalytic material for biocathodes in MESs to significantly enhance the CO2 conversion.


Asunto(s)
Estructuras Metalorgánicas , Estructuras Metalorgánicas/química , Cobre/química , Dióxido de Carbono/química , Bacterias , Electrodos
12.
Front Chem ; 10: 1038221, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36531314

RESUMEN

The rising demand of energy and lack of clean water are two major concerns of modern world. Renewable energy sources are the only way out in order to provide energy in a sustainable manner for the ever-increasing demands of the society. A renewable energy source which can also provide clean water will be of immense interest and that is where Photocatalytic Fuel Cells (PFCs) exactly fit in. PFCs hold the ability to produce electric power with simultaneous photocatalytic degradation of pollutants on exposure to light. Different strategies, including conventional Photoelectrochemical cell design, have been technically upgraded to exploit the advantage of PFCs and to widen their applicability. Parallel to the research on design, researchers have put an immense effort into developing materials/composites for electrodes and their unique properties. The efficient strategies and potential materials have opened up a new horizon of applications for PFCs. Recent research reports reveal this persistently broadening arena which includes hydrogen and hydrogen peroxide generation, carbon dioxide and heavy metal reduction and even sensor applications. The review reported here consolidates all the aspects of various design strategies, materials and applications of PFCs. The review provides an overall understanding of PFC systems, which possess the potential to be a marvellous renewable source of energy with a handful of simultaneous applications. The review is a read to the scientific community and early researchers interested in working on PFC systems.

13.
Front Genet ; 13: 930792, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36035193

RESUMEN

Most of the human genome, except for a small region that transcribes protein-coding RNAs, was considered junk. With the advent of RNA sequencing technology, we know that much of the genome codes for RNAs with no protein-coding potential. Long non-coding RNAs (lncRNAs) that form a significant proportion are dynamically expressed and play diverse roles in physiological and pathological processes. Precise spatiotemporal control of their expression is essential to carry out various biochemical reactions inside the cell. Intracellular organelles with membrane-bound compartments are known for creating an independent internal environment for carrying out specific functions. The formation of membrane-free ribonucleoprotein condensates resulting in intracellular compartments is documented in recent times to execute specialized tasks such as DNA replication and repair, chromatin remodeling, transcription, and mRNA splicing. These liquid compartments, called membrane-less organelles (MLOs), are formed by liquid-liquid phase separation (LLPS), selectively partitioning a specific set of macromolecules from others. While RNA binding proteins (RBPs) with low complexity regions (LCRs) appear to play an essential role in this process, the role of RNAs is not well-understood. It appears that short nonspecific RNAs keep the RBPs in a soluble state, while longer RNAs with unique secondary structures promote LLPS formation by specifically binding to RBPs. This review will update the current understanding of phase separation, physio-chemical nature and composition of condensates, regulation of phase separation, the role of lncRNA in the phase separation process, and the relevance to cancer development and progression.

14.
J Pharm Bioallied Sci ; 14(Suppl 1): S644-S648, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36110582

RESUMEN

Context: Several options to restore the missing teeth are currently available; however, minimal information is there regarding the tooth loss consequences and knowledge of the various prosthetic options in the Indian population. Aim: The aim of this study was to investigate the perception, awareness, and practice about missing teeth, prosthetic options, and knowledge about dental implants among the adult population of Jharkhand state. Materials and Methods: A questionnaire-based cross-sectional study was carried out on 400 participants. The questionnaire was divided into two sections, i.e., perception awareness and practice about missing teeth, its consequences, and prosthetic options and the second part was about the knowledge of dental implants. Statistical Analysis: Chi-square test was applied for comparison, and P < 0.05 was considered statistically significant. Results: Maximum numbers of people 178 (44.5%) were interested to get their teeth replaced as a definite requirement. Loss of esthetics as a consequence after tooth loss was known to 72.5% followed by tilting of adjacent teeth (47%). Awareness for prosthetic options available after tooth loss was highest (71.5%) for fixed partial denture's (Bridge). Sixty-three percentage of the studied population had not replaced their missing teeth with any dental prosthesis. Knowledge about dental implants was restricted to a meager of 84 (21%) of the participants. Dentist was the main source of information for dental implants, followed by media. Conclusion: Awareness of patients toward missing teeth and its consequences requires more emphasis. Special effort is needed to improve the knowledge of dental implants among the less educated population of this region.

15.
Cureus ; 14(12): e32368, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36632276

RESUMEN

BACKGROUND: The concept of the pathogenesis and etiology of periodontal disease, with their infectious and chronic natures, usually facilitates acknowledging the possibility of these infections influencing events elsewhere in the body. Concurrent awareness and recognition of the interaction between systemic and oral diseases are one of the enormous advances that require a periodontist to not only strictly direct their knowledge toward prevention and treatment but also spread awareness about the same among the unknown. Thus, the primary goal of our study was to assess public awareness of periodontal and systemic interrelationships with oral hygiene practices in Ranchi, Jharkhand. METHODOLOGY:  A total of 800 subjects between ages 18 and 60 years visiting the outpatient department of periodontology, Dental Institute, Rajendra Institute of Medical Sciences (RIMS), were randomly selected for inclusion in the study. After the oral hygiene checkup, the patients were presented with a self-constructed questionnaire form, where patients' awareness and knowledge about perio-systemic interrelationship and their patterns about oral hygiene practices were assessed. RESULTS: The data collected was analyzed using mean and standard deviation (SD), while the chi-square (χ2) test was to evaluate the mean difference. The results of our study showed a fair oral hygiene index, minimal oral hygiene practices, and a lack of awareness regarding the interrelationship between bad oral health and systemic diseases among the population of Ranchi. Out of 800 subjects, the majority (around 44.25%) visited a dentist only if and when needed, and around 80% of the population continued using their toothbrushes for more than six months. In fact, awareness regarding the perio-systemic interrelationship was only among 5.12% (3.25% ± 1.87%) of the total population. CONCLUSION: Within the limitations of our study, it can be concluded that there is a need to educate the general population about the pros and cons of maintaining oral hygiene. Dental awareness, along with periodontal health care and its impact on systemic health, should be intensified through various means.

16.
J Oral Maxillofac Pathol ; 25(Suppl 1): S68-S70, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34083975

RESUMEN

Dentigerous cyst (DC) and ossifying fibroma (OF) are intraosseous lesions of the jaw. Both are varied pathological entities with a wide spectrum of clinical and histological features along with distinct treatment plan and prognosis. While OF comes under fibro-osseous lesions of the jaws, DC is a developmental odontogenic cyst which is formed by the accumulation of fluid between reduced enamel epithelium and enamel or between layers of the enamel organ. This case report presents a rare display of two distinct pathologies synchronously and aims to discuss the possible histogenesis for the same.

17.
Cell Rep ; 36(8): 109588, 2021 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-34433050

RESUMEN

Radial glia-like (RGL) stem cells persist in the adult mammalian hippocampus, where they generate new neurons and astrocytes throughout life. The process of adult neurogenesis is well documented, but cell-autonomous factors regulating neuronal and astroglial differentiation are incompletely understood. Here, we evaluate the functions of the transcription factor zinc-finger E-box binding homeobox 1 (ZEB1) in adult hippocampal RGL cells using a conditional-inducible mouse model. We find that ZEB1 is necessary for self-renewal of active RGL cells. Genetic deletion of Zeb1 causes a shift toward symmetric cell division that consumes the RGL cell and generates pro-neuronal progenies, resulting in an increase of newborn neurons and a decrease of newly generated astrocytes. We identify ZEB1 as positive regulator of the ets-domain transcription factor ETV5 that is critical for asymmetric division.


Asunto(s)
Autorrenovación de las Células/fisiología , Hipocampo/metabolismo , Homeobox 1 de Unión a la E-Box con Dedos de Zinc/metabolismo , Animales , Diferenciación Celular/genética , Células Ependimogliales/metabolismo , Transición Epitelial-Mesenquimal/fisiología , Hipocampo/efectos de los fármacos , Humanos , Ratones , Neurogénesis/fisiología , Neuronas/metabolismo
18.
Chem Sci ; 12(6): 2071-2077, 2020 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34163970

RESUMEN

Rational design and shaping of soft smart materials offer potential applications that cannot be addressed with rigid systems. In particular, electroresponsive elastic materials are well-suited for developing original active devices, such as pumps and actuators. However, applying the electric stimulus requires usually a physical connection between the active part and a power supply. Here we report about the design of an electromechanical system based on conducting polymers, enabling the actuation of a wireless microfluidic pump. Using the electric field-induced asymmetric polarization of miniaturized polypyrrole tubes, it is possible to trigger simultaneously site-specific chemical reactions, leading to shrinking and swelling in aqueous solution without any physical connection to a power source. The complementary electrochemical reactions occurring at the opposite extremities of the tube result in a differential change of its diameter. In turn, this electromechanical deformation allows inducing highly controlled fluid dynamics. The performance of such a remotely triggered electrochemically active soft pump can be fine-tuned by optimizing the wall thickness, length and inner diameter of the material. The efficient and fast actuation of the polymer pump opens up new opportunities for actuators in the field of fluidic or microfluidic devices, such as controlled drug release, artificial organs and bioinspired actuators.

19.
ACS Appl Mater Interfaces ; 12(32): 36548-36557, 2020 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-32683858

RESUMEN

The development of surfaces with chiral features is a fascinating challenge for modern materials science, especially when they are used for chiral separation technologies. In this contribution, the design of hierarchically structured chiral macroporous zeolitic imidazolate framework-8 (ZIF-8) electrodes is presented. They are elaborated by an electrochemical deposition-dissolution technique based on the electrodeposition of metal through a colloidal crystal template, followed by controlled electrooxidation. This generates locally metal cations, which can interact with a chiral ligand present in the solution to form metal-organic frameworks (MOFs). The macroporous structure facilitates the access of the chiral recognition sites, located in the mesoporous MOF, and thus helps to overcome mass transport limitations. The efficiency of the designed functional materials for chiral adsorption and separation can be fine-tuned by applying an adjustable electric potential to the electrode surfaces. This hierarchical chiral ZIF-8 structure was deposited at the walls of a microfluidic device and used as a stationary phase for enantioselective separation. The potential-controlled interaction between the stationary phase and the chiral analytes allows baseline separation of two enantiomers. This opens up interesting perspectives for using hierarchically structured chiral MOFs as an efficient material for the selective adsorption and separation of chiral compounds.

20.
Nat Cancer ; 1(10): 976-989, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-33073241

RESUMEN

Oxidative phosphorylation (OXPHOS) defects caused by somatic mitochondrial DNA (mtDNA) mutations increase with age in human colorectal epithelium and are prevalent in colorectal tumours, but whether they actively contribute to tumorigenesis remains unknown. Here we demonstrate that mtDNA mutations causing OXPHOS defects are enriched during the human adenoma/carcinoma sequence, suggesting they may confer a metabolic advantage. To test this we deleted the tumour suppressor Apc in OXPHOS deficient intestinal stem cells in mice. The resulting tumours were larger than in control mice due to accelerated cell proliferation and reduced apoptosis. We show that both normal crypts and tumours undergo metabolic remodelling in response to OXPHOS deficiency by upregulating the de novo serine synthesis pathway (SSP). Moreover, normal human colonic crypts upregulate the SSP in response to OXPHOS deficiency prior to tumorigenesis. Our data show that age-associated OXPHOS deficiency causes metabolic remodelling that can functionally contribute to accelerated intestinal cancer development.


Asunto(s)
Neoplasias Intestinales , Enfermedades Mitocondriales , Animales , Transformación Celular Neoplásica/genética , ADN Mitocondrial/genética , Neoplasias Intestinales/genética , Ratones , Mitocondrias/genética , Mutación
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