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Different renewable bio-based routes leading to the versatile bioproduct c-valerolactone (GVL) were studied in integrated fashions, starting from furfural (Fur), a-angelica lactone (AnL) and levulinic acid (LA), in the presence of multifunctional hafnium-containing catalysts, in alcohol media. These routes involved acid and reduction reactions for which multifunctional catalysts were prepared via top-down strategies, namely the nanocatalyst Hf-deAlBeta-n and the hierarchical (intracrystalline micro/mesopores) microcrystalline material Hf-WdeSAlBeta-m. Mechanistic and kinetic modelling studies, molecular-level investigations by solid-state spectroscopic characterization, and catalyst stability studies led to assessments about the catalytic roles and potentialities of the prepared materials for GVL production. The influences of the catalytic reaction conditions and type of transition metal in the catalysts were studied. The best-performing catalyst was the hierarchical zeotype Hf-WdeSAlBeta-m (GVL yields of up to 99% from LA, 91% from AnL, and 73% from Fur, at 180 C), which correlated with its enhanced acidity and mesoporosity. To the best of our knowledge, this is the first reported hafnium-containing BEA zeotype possessing an intracrystalline hierarchical pore system, and the results highlighted the catalytic potentialities of these types of materials for the integrated production of GVL. published

Immune infertility occurs due to the presence of antisperm antibodies (ASA). This type of infertility has a relatively low prevalence (2.6–6.6% in infertile men), and its etiology, risk factors, targets, and consequences for male fertility are not completely understood. While it is largely accepted that abnormalities in the blood–testis barrier and/or blood–epididymal barrier are the main factors behind its etiology, and that sperm motility is the most frequently reported altered parameter, few are the well-defined risk factors and ASA targets only now started to be disclosed, with proteins involved in sperm–oocyte interaction rising as the most significant. The development of potential treatments is also limited, being the corticosteroids the more promising. Overall, there are still many knowledge gaps related to immune infertility. With this review, we aimed to gather all the information collected from studies developed in humans in the last decade. Despite the controversial results/inconsistencies, that are not only a result of the complexity of mechanisms/variables involved in ASA infertility but also from the technical approaches to assess ASA and the lack of a consensus regarding the thresholds to be used, this manuscript aims to bring a fresh update on the field. It has become clear that, to obtain more/reliable data, there is a need to assess ASA in all the routine seminal analyses, following WHO recommendations. In this way, it will be possible to obtain consistent and comparable information, that can add to current knowledge. Additionally, multicentric studies with large cohorts are also missing, and future research should take this into consideration.

The selective chemical conversion of biomass components to useful bioproducts may contribute to a renewable resource-based economy. The selective production of target bioproducts may be accomplished using heterogeneous catalysts operating under relatively moderate reaction conditions. In this work, carbohydrate biomass derived α-angelica lactone (AnL) and levulinic acid (LA) were converted to the versatile bioproduct γ-valerolactone (GVL), in the presence of nanohybrid catalysts (M-FDCA) and the microcrystalline metal-organic framework CAU-28, all of which were synthesized from bio-based 2,5-furandicarboxylic acid (FDCA) and a metal (M = Zr or Hf) precursor. The nanohybrids were prepared in a simple fast (FT) fashion, and, for comparison, via a conventional solvothermal (S) procedure. The M-FDCA catalysts stood on a higher footing than CAU-28 in the conversion of AnL and LA to GVL. The superior results for the M-FDCA catalysts may be partly due to their higher ratio Sext:SBET and nano-features, which may advantageously enhance active sites accessibility. In particular, the Hf-FDCA catalysts were stable and performed superiorly to the Zr-FDCA ones. Experimental mechanistic studies shed light on the multifunctional behavior of the hybrid catalysts in the one-pot conversion of AnL-to-GVL, which involved acid and reduction chemistry.

BACKGROUND Spermicides have been identified as a potentially attractive alternative to hormonal contraceptives and/or intrauterine devices. Thus, this study aimed evaluating the efficacy and local tolerance of benzalkonium chloride (BKC) and myristalkonium chloride (MKC) contained in Pharmatex® vaginal formulations and compare them with nonoxynol-9 (N-9), the most common active ingredient in topical vaginal contraceptives. METHODS Human normozoospermic samples were assessed for motility, viability, acrosome status and penetration ability after exposure to control, N-9 or different BKC and MKC doses for 0 and 10 minutes. Local tolerance on HeLa cells was evaluated by the Trypan-blue and MTT assays. RESULTS Exposure to BKC and MKC reduced acrosome integrity while promoting total immobilisation and complete loss of sperm viability (p

Reproducing both the mechanical and biological performance of native blood vessels remains an ongoing challenge in vascular tissue engineering. Additive-lathe printing offers an attractive method of fabricating long tubular constructs as a potential vascular graft for the treatment of cardiovascular diseases. Printing hydrogels onto rotating horizontal mandrels often leads to sagging, resulting in poor and variable mechanical properties. In this study, an additive-lathe printing system with a vertical mandrel to fabricate tubular constructs is presented. Various concentrations of gelatin methacryloyl (gelMA) hydrogel were used to print grafts on the rotating mandrel in a helical pattern. The printing parameters were selected to achieve the bonding of consecutive gelMA filaments to improve the quality of the printed graft. The hydrogel filaments were fused properly under the action of gravity on the vertical mandrel. Thus, the vertical additive-lathe printing system was used to print uniform wall thickness grafts, eliminating the hydrogel sagging problem. Tensile testing performed in both circumferential and longitudinal direction revealed that the anisotropic properties of printed gelMA constructs were similar to those observed in the native blood vessels. In addition, no leakage was detected through the walls of the gelMA grafts during burst pressure measurement. Therefore, the current printing setup could be utilized to print vascular grafts for the treatment of cardiovascular diseases.

The handleability and sensory perception of hand sanitisers by consumers affect the hygiene outcome. Spillage may result in under-dosing and poor sensory properties can lead to under-utilisation. We first propose four principles (low run off, spreadability, smoothness and non-stickiness) for designing the rheology of thickened alcohol-based hand rubs with acceptable handleability and hand feel. We then evaluate a commercial hand gel and a variety of simplified formulations thickened with microgels (Carbopol 974P, Carbopol Ultrez 20 and Sepimax Zen), or linear polymers (Jaguar HP 120 COS), and evaluate them against these design criteria. All four additives provide acceptable spreadability by shear thinning to $\eta \approx 10^{-1} Pa \, s$ at $\dot\gamma \sim 10^3 s^{-1}$. Either the finite yield stress conferred by the microgels ($\sigma_y \gtrsim 10 Pa$) or the increase in low-shear viscosity provided by the linear polymer ($\eta \gtrsim 1 Pa \, s$ at $\dot\gamma \lesssim 0.1 s^{-1}$) give rise to acceptably low run-off. However, the formulation using the linear polymer shows a filament breakage time of $\tau_{\rm b} \approx 1 s$ in capillary rheology, which may result in stickiness and therefore a less than optimal hand feel., Comment: 10 pages, 8 figures

The confinement and catalytic behavior of Mo(CO)6 species inside UiO-66 (zirconium and hafnium) metal-organic frameworks (MOFs) have been investigated by means of multitechnique characterization and catalytic olefin epoxidation. Mo(CO)6 was encapsulated in nanocrystalline MOFs by solvothermal and vapor phase impregnation methods (STI and VPI, respectively), resulting in Mo loadings of 2.0–8.8 wt% (STI) or 15 wt% (VPI). Powder X-ray diffraction, SEM-EDS, N2 adsorption, FT-IR and 13C{1H} CP MAS NMR collectively confirmed immobilization within the pore spaces of the hosts, which maintained their bulk crystallinity and crystal morphologies. CO resonances in the 13C{1H} CP MAS NMR spectra were assigned to hexacarbonyl guest molecules located in the larger pore spaces, such as the octahedral cavities (for STI and VPI samples), and in more restricted environments such as the tetrahedral cavities (for the VPI sample). FT-IR spectra displayed the characteristic pattern of νCO stretching modes for an octahedral symmetry molecule slightly perturbed by interaction of one of the carbonyl groups with the MOF support. The spectra evidenced the formation of a weak hydrogen bonding interaction of the type μ3-OH···OCMo(CO)5 involving the μ3-OH groups that are exclusively present in the tetrahedral cavities of the UiO-66 structure. The Mo(CO)6 loaded MOFs are active and reusable pre-catalysts for cis-cyclooctene epoxidation, exhibiting excellent epoxide selectivity (up to quantitative epoxide yield within 1 h reaction) and tert-butyl hydroperoxide efficiency. Catalyst recycling and retention of structural integrity were demonstrated for UiO-66(Hf) loaded with 8.8 wt% Mo by the STI method. The UiO-66(Hf) host may be a better catalyst support than its Zr counterpart due its smaller crystallite size (≈100 nm) and higher defectivity. The substrate scope was broadened for Mo(8.8-STI)/Hf-MOF which promoted the epoxidation of biobased olefins (methyl oleate and dl -limonene) and oxidative dehydrogenation cyclooctanol to cyclooctanone.

A positive relationship between mitochondrial functionality and gamete quality, ultimately contributing to fertilization success and normal embryo development has been established for some years now. Both mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) production are major indicators of mitochondrial function, and the need for accurate biomarkers mirroring gamete quality highlights the importance of a precise assessment of mitochondrial quality and function. In this chapter, we discuss the use of some mitochondrial fluorescent probes coupled to flow cytometry and/or fluorescence microscopy to specifically assess mitochondrial ROS production and MMP in both sperm and oocytes. Furthermore, as the distribution/aggregation of mitochondria in the oocyte is of interest to determine its quality, a detailed protocol is also given. These methodologies are easy, accurate and can be safely applied in research- and/or clinical-based contexts.

A carbon monoxide-releasing material (CORMA) has been prepared by inclusion of molybdenum hexacarbonyl in a hafnium-based metal-organic framework (MOF) with the UiO-66 architecture. Mo(CO)6 was adsorbed from solution to give supported materials containing 6.0–6.6 wt% Mo. As confirmed by powder X-ray diffraction (PXRD) and SEM coupled with energy dispersive X-ray spectroscopy, neither the crystallinity nor the morphology of the porous host was affected by the loading process. While the general shape of the N2 physisorption isotherms (77 K) did not change significantly after encapsulation of Mo(CO)6, the micropore volume decreased by ca. 20%. Thermogravimetric analysis of the as-prepared materials revealed a weight loss step around 160 °C associated with the decomposition of Mo(CO)6 to subcarbonyl species. Confirmation for the presence of encapsulated Mo(CO)6 complexes was provided by FT-IR and 13C{1H} cross-polarization magic-angle spinning NMR spectroscopies. To test the capability of these materials to behave as CORMAs and transfer CO to heme proteins, the standard myoglobin (Mb) assay was used. While stable in the dark, photoactivation with low-power UV light (365 nm) liberated CO from the encapsulated hexacarbonyl molecules in Mo(6.0)/UiO-66(Hf), leading to a maximum amount of 0.26 mmol CO released per gram of material. Under the simulated physiological conditions of the Mb assay (37 °C, pH 7.4 buffer), minimal leaching of molybdenum occurred, PXRD showed only slight amorphization, and FT-IR spectroscopy confirmed the high chemical stability of the MOF host.

A positive relationship between mitochondrial functionality and gamete quality, ultimately contributing to fertilization success and normal embryo development has been established for some years now. Both mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) production are major indicators of mitochondrial function, and the need for accurate biomarkers mirroring gamete quality highlights the importance of a precise assessment of mitochondrial quality and function. In this chapter, we discuss the use of some mitochondrial fluorescent probes coupled to flow cytometry and/or fluorescence microscopy to specifically assess mitochondrial ROS production and MMP in both sperm and oocytes. Furthermore, as the distribution/aggregation of mitochondria in the oocyte is of interest to determine its quality, a detailed protocol is also given. These methodologies are easy, accurate and can be safely applied in research- and/or clinical-based contexts.

O presente trabalho aborda um estudo que procurou compreender as perspetivas dos professores e alunos sobre os Trabalhos Para Casa (TPC) em Ciências Naturais, no 2.º Ciclo do Ensino Básico e que foi desenvolvido no âmbito do Mestrado em Ensino do 1.º Ciclo do Ensino Básico e de Matemática e Ciências Naturais do 2.º Ciclo do Ensino Básico, na Escola Superior de Educação de Viseu. Para o efeito, recorreu-se ao inquérito por questionário e à entrevista na modalidade de focus group. Os questionários foram aplicados a uma amostra de 13 professores do 5.º e 6.º anos de escolaridade do concelho de Viseu e a 369 alunos, na sua grande maioria, com idades compreendidas entre os 10 e os 12 anos. A entrevista, subsequente a uma atividade experimental como TPC, foi realizada a quatro grupos de alunos de uma turma do 5.º ano. Os resultados revelaram que os professores solicitam semanalmente TPC nesta disciplina, considerando-os muito importantes para o processo de ensino-aprendizagem. Verificou-se que a maioria dos TPC tem origem no manual escolar, em consonância com o que sucede noutras disciplinas. Os profissionais revelaram estar cientes de que os seus alunos estão a perder o entusiasmo e interesse pelos TPC, mas a grande pressão causada pelos programas e até pelos próprios pais, que tendem a avaliar o professor pela quantidade de TPC que solicitam, tem prejudicado o modo, o tipo e a quantidade de TPC que requerem. Relativamente aos alunos, na sua maioria, apurou-se que realizam os TPC e também os consideram importantes, uma vez que os ajudam a estudar, aumentam a curiosidade e melhoram os seus hábitos de estudo. As tarefas que realizam com maior frequência e aquelas que os professores também solicitam mais vezes são as fichas do manual escolar. Contudo, através da entrevista, pudemos constatar que os alunos reagem com mais entusiasmo e motivação a TPC inovadores, fora do contexto tradicional. Como se evidenciou, os discentes preferem TPC em que desempenhem um papel ativo, que façam sentido e impliquem uma maior iniciativa e protagonismo da sua parte, no processo de ensino-aprendizagem. This work addresses a study which tried to understand the teachers and students' perspectives about homework in Natural Sciences, in the 2nd Cycle of Basic Education, developed in the Master Primary Education and Mathematics and Natural Sciences Teaching (5th and 6th grades), in the Higher School of Education of Viseu, Portugal. Thus, in the investigation it was used a survey done by questionnaire and by focus group interview. The questionnaires were applied to a sample of 13 teachers of the 5th and 6th grades in the municipality of Viseu and to 369 students, majorly aged between 10 and 12 years old. The interview, performed after an experimental activity as homework, was applied to four groups of a 5th graders class. The results show that teachers ask for homework weekly in this subject, considering it very important for the teaching-learning process. It was verified that the majority of the homework has its origin in the schoolbook, as it happens in other subjects. Professionals revealed to be aware that their students are losing their enthusiasm and interest in homework, but the great pressure caused by the programs and even by the parents themselves, who tend to evaluate the teacher by the amount of homework they request, has spoilt the way, the type and amount of homework they require. Regarding the students, it was found that the majority of them do their homework and they also consider it important, since it helps them study, it increases curiosity and improves their study habits. The tasks they do more frequently and the one that teachers also request more often are from the school handbook. However, with the interview, we could also verify that students react with more enthusiasm and motivation to innovative homework, outside the traditional context. As evidenced, students prefer homework in which they play an active role, which make sense, and which imply a greater initiative and protagonism on their part in the teaching-learning process info:eu-repo/semantics/publishedVersion

Mesostructured solid acid catalysts based on the BEA topology were explored for olefin oligomerisation, which is an attractive synthetic route to produce clean, sulphur-free fuels or fuel additives with reduced aromatics content. Specifically, the oligomerisation of 1-butene, which may derive from (non)renewable sources, was carried out under high pressure and continuous-flow operation. The mesostructured catalysts consisted of a hierarchical zeotype (BEA-hier) synthesized via one-pot approach using a dual function template, and, on the other hand, a composite (BEA/TUD) possessing zeolite nanocrystallites embedded in a mesoporous matrix synthesised under hydrothermal conditions. The influence of the material properties, catalyst activation temperature and reaction parameters were investigated combining characterisation, GC×GC-ToFMS and catalytic studies. The catalytic performances were compared to commercial nano/microcrystalline zeolites of different topologies, and COD-900 (type of catalyst for the Conversion of Olefins to Distillates process). BEA-hier performed superiorly in terms of conversion and space-time yields to diesel cut products.

TUD-1 type mesoporous aluminosilicates were explored for the acid-catalysed oligomerisation of 1-butene, under high pressure, continuous flow operation, which is an attractive route to produce sulphur-free synthetic fuels with reduced aromatics content. The solid acid catalysts were synthesised via one-pot synthesis (HT) or stepwise approach (PG), without using surfactants as templates, which is an eco-friendly characteristic of the TUD-1 family. While the HT approach may be advantageous in terms of process intensification in relation to the PG one, the latter may lead to relatively low molar ratios Si/Al. The catalysts possessed Si/Al ratios in the range 3–5 and 17–35 for the PG and HT approaches, respectively, pore sizes in the range 10–14 nm, and essentially Lewis acidity. To the best of our knowledge, this is the first report of siliceous oxide TUD-1 furnished with acidity via post-synthesis grafting (PG) of Al-species. For comparative studies, an ordered mesoporous aluminosilicate was synthesised via the PG approach using surfactant mixtures. All materials prepared promoted the reaction of 1-butene to higher molar mass products. The best-performing catalyst in terms of space-time yields of the 170–390 °C cut (boiling point range) products (of the type middle distillates) was Al-TUD-1(25)-HT synthesised via the HT method. The products were analysed by comprehensive two-dimensional gas chromatography (GC × GC) combined with time-of-flight mass spectrometry (ToFMS). The influence of material properties and process parameters on the catalytic reaction, and catalyst stability were studied. The catalytic performances were benchmarked with ZSM-5 (zeolite used in commercial oligomerisation processes).

The oligomerisation of 1-butene was studied under high-pressure continuous-flow conditions (200–250 °C, 30–40 bar), in the presence of micro/mesoporous zeotypes based on the MFI topology, which were prepared via different non-destructive bottom-up strategies: crystallization of silanized protozeolitic units; co-templating with a dual function (polymeric) template; and using a sole structure directing agent (non-surfactant and non-polymeric) to generate mesoporosity. The synthesis method influenced the material properties and consequently the catalytic performance. In targeting hydrocarbons with boiling point ranges characteristics of diesel, the zeotypes benefited from regular morphology, reduced crystallite size, mesoporosity and enhanced molar ratio of Lewis (L) to Bronsted (B) acid sites (L/B). In general, the zeotypes outperformed commercial zeolite ZSM-5. The best-performing zeotype was prepared according to the Serrano strategy based on the crystallization of silanized zeolitic seeds, and led to 97% conversion and an average space-time yield of liquid products of 1077 mg gcat−1 h−1, at 250 °C, 40 bar. The zeotypes seemed more stable than the commercial zeolite, based on molecular level characterization studies of the used/regenerated catalysts, with some differences in catalytic activity.

Ordered porous silicates of the type TUD-1 and zeolite beta possessing zirconium and aluminium sites were evaluated as eco-friendly heterogeneous, multifunctional catalysts for the integrated reduction-acid conversion of furfural (Fur, industrially produced from hemicellulosic components of biomass) to useful bio-products, namely, furfuryl alcohol (FA), alkyl furfuryl ethers (FEs), alkyl levulinate esters (LEs), levulinic acid (LA), angelica lactones (AnLs), and gamma-valerolactone (GVL); the bio-products spectrum was obtained by GC x GC-ToFMS. Carrying out the one-pot conversion of Fur to bio-products using a multifunctional catalyst is challenging since various reactions are involved and it is difficult to control all of these to meet high reaction efficiencies and selectivities. Aiming at designing improved multifunctional catalysts for this reaction system, the TUD-1 and zeolite beta type silicates possessing zirconium and aluminium sites in different ratios were prepared and characterised on microstructural and molecular levels. Systematic characterisation, catalytic testing using 2-butanol as dual functional solvent-H-donor, and kinetic modelling studies were performed using the Zr,Al-containing micro- and mesoporous materials. Different steps of the overall reaction of Fur were studied separately starting from intermediate products using the same materials, which helped understand the influence of the material properties on reactivity of intermediates and reaction selectivity. Zr-sites of the silicate catalysts were essential for effectively initialising the overall process (reduction of Fur to FA), and for the reduction of LEs to GVL; the co-presence of Al-sites promoted acid-catalysed steps (FA to FEs, LEs, AnLs, LA). The good stability of the catalysts was verified by catalytic and characterisation studies of the spent catalysts. (C) 2015 Elsevier B.V. All rights reserved.

Oligomerization of light olefins allows the production of clean, sulphur-free fuels or fuel additives with reduced aromatics content, and useful chemicals. Commercial heterogeneous catalytic oligomerization technologies were developed to meet market demands in flexible fashions, whereby the operating conditions may be adjusted in favor of the desired product specifications and yields. For achieving superior performances, the development of expeditious evaluation and optimization tools is important, albeit not trivial because light olefins oligomerization involves complex reaction systems and product quality depends on many factors. In this sense, the design of experiments (DoE) and response surface methodology (RSM) are valuable tools, yet unexploited for light olefins oligomerization processes. In this work, DoE/RSM models were developed and validated for the oligomerization of 1-butene – derivable from fossil or renewable sources of organic carbon – over a superior hierarchical zeotype catalyst, under high pressure, continuous flow conditions, targeting clean diesel range products. The models allowed to investigate the individual and cross effects of reaction pressure, temperature and weight hourly space velocity on conversion and yields of specific product fractions. The optimization studies also accounted for product quality features such as, reduced aromatics content; these studies counted with the analytical input of Comprehensive Two-Dimensional Gas Chromatography with Time-of-Flight Mass Spectrometry (GC×GC-ToFMS) for characterizing the products. Importantly, DoE/RSM tools may contemplate not only kinetic data, but also product quality indicators, and help identify most relevant process parameters impacting on the productivity.

The reduced number of animals in most wild felid populations implies a loss of genetic diversity. The death of juveniles, prior to the production of mature sperm, represents a loss of potential genetic contribution to future populations. Since 2011 mouse testicular organ culture has demonstrated an alternative mechanism to produce sperm in vitro from immature tissue. However, extension of this technology to other species has remained limited. We have used domestic cat (Felis catus) as a model for wild felids to investigate spermatogenesis initiation and regulation. Contrary to expectations, no germ cell differentiation could be detected and we could show that KSR is deleterious for felid spermatogenesis. Nevertheless spermatogonial viability was maintained for 6 weeks.

Diabetes mellitus has been increasing at alarming rates in recent years, thus jeopardizing human health worldwide. Several antidiabetic drugs have been introduced in the market to manage glycemic levels, and proven effective in avoiding, minimizing or preventing the appearance or development of diabetes mellitus-related complications. However, and despite the established association between such pathology and male reproductive dysfunction, the influence of these therapeutic interventions on such topics have been scarcely explored. Importantly, this pathology may contribute toward the global decline in male fertility, giving the increasing preponderance of diabetes mellitus in young men at their reproductive age. Therefore, it is mandatory that the reproductive health of diabetic individuals is maintained during the antidiabetic treatment. With this in mind, we have gathered the available information and made a critical analysis regarding the effects of several antidiabetic drugs on male reproductive function. Unlike insulin, which has a clear and fundamental role on male reproductive function, the other antidiabetic therapies' effects at this level seem incoherent. In fact, studies are highly controversial possibly due to the different experimental study approaches, which, in our opinion, suggests caution when it comes to prescribing such drugs to young diabetic patients. Overall, much is still to be determined and further studies are needed to clarify the safety of these antidiabetic strategies on male reproductive system. Aspects such as the effects of insulin levels variations, consequent of insulin therapy, as well as what will be the impact of the side effect hypoglycemia, common to several therapeutic strategies discussed, on the male reproductive system are still to be addressed.

The alarming increase in the number of diabetic patients worldwide raises concerns regarding the impact of the disease on global health, not to mention on social and economic aspects. Furthermore, the association of this complex metabolic disorder with male reproductive impairment is worrying, mainly due to the increasing chances that young individuals, at the apex of their reproductive window, could be affected by the disease, further contributing to the disturbing decline in male fertility worldwide. The cornerstone of diabetes management is glycemic control, proven to be effective in avoiding, minimizing or preventing the appearance or development of disease-related complications. Nonetheless, the possible impact of these therapeutic interventions on male reproductive function is essentially unexplored. To address this issue, we have made a critical assessment of the literature on the effects of several antidiabetic drugs on male reproductive function. While the crucial role of insulin is clear, as shown by the recovery of reproductive impairments in insulin-deficient individuals after treatment, the same clearly does not apply to other antidiabetic strategies. In fact, there is an abundance of controversial reports, possibly related to the various study designs, experimental models and compounds used, which include biguanides, sulfonylureas, meglitinides, thiazolidinediones/glitazones, bile acid sequestrants, amylin mimetics, as well as sodiumglucose co-transporter 2 (SGLT2) inhibitors, glucagon-like peptide 1 (GLP1), α-glucosidase inhibitors and dipeptidyl peptidase 4 (DPP4) inhibitors. These aspects constitute the focus of the current review.

Chlorhexidine is among the most used biocides in Europe, however its toxicity to aquatic organisms is scarcely known. The main objective of this study was to assess the lethal and sub lethal effects of chlorhexidine digluconate (ChD) on four aquatic model organisms: the bacteria Vibrio fischeri, the algae Pseudokirchneriella subcapitata, the crustacean Daphnia magna and the embryos of the fish Danio rerio. ChD was very toxic to algae and crustaceans, with a 72 h-EC50 of 62.2 μg/l and a 48 h-EC50 of 45.0 μg/l, respectively. Toxicity to fish embryos and the bacteria was lower, with a 96 h-EC50 of 804.0 μg/l and a 15 min-EC50 of 1,694.0 μg/l, respectively. Concerning sub lethal effects on D. magna (feeding inhibition) a 6 h-EC50 of 503.7 μg/l was obtained. In fish, ChD caused developmental abnormalities, namely alterations in the amniotic fluid (48 h-EC20 of 753.6 μg/l) and early hatching. Moreover, enzymatic biomarkers on fish embryos showed an induction of cholinesterase activity in all ChD tested concentrations (80-900 μg/l). The catalase activity was also induced at the highest concentration tested (900 μg/l) whereas no changes were observed for glutathione-S-transferase and lactate dehydrogenase activities. The toxicity of ChD to the algae and crustacean raises concerns about its potential effects in aquatic food webs, since these organisms are in the base of trophic chains, and highlights the need for further studies on ChD toxicity to aquatic organisms. published

The sustainable conversion of biomass and biomass-derived platform chemicals demands efficient catalytic processes for which modified versions of zeolites can be strategically important. The catalytic potential of bulk and composite catalysts which simultaneously feature zeolite crystallinity, mesoporosity and Zr and Al sites were explored for the valorisation of furfural (Fur; industrially produced from hemicelluloses) via integrated reduction and acid reactions in alcohol media, to give useful bio-products (bioP), namely, furanic ethers, levulinate esters and angelica lactones. Different synthetic strategies were used starting from zeolite microcrystals or nanocrystals. A composite consisting of nanocrystals of Zr,Al-Beta embedded in a mesoporous matrix is reported for the first time. In a different synthesis approach, a bulk mesoporous zeotype material was prepared by post-synthesis alkaline/acid/impregnation treatments, and explored for the first time as a catalyst for a one-pot reduction/acid reaction system. Characterisation studies of the morphology, structure, texture and nature of the Al and Zr sites (Al-27 MAS NMR spectroscopy, FT- IR spectroscopy of adsorbed pyridine or deuterated acetonitrile) helped understand the influence of material properties on catalytic performance. These types of materials are active and stable catalysts for the integrated conversion of Fur to bioP.

Acquisition of energy is central to life. In addition to the synthesis of ATP, organisms need energy for the establishment and maintenance of a transmembrane difference in electrochemical potential, in order to import and export metabolites or to their motility. The membrane potential is established by a variety of membrane bound respiratory complexes. In this work we explored the diversity of membrane respiratory chains and the presence of the different enzyme complexes in the several phyla of life. We performed taxonomic profiles of the several membrane bound respiratory proteins and complexes evaluating the presence of their respective coding genes in all species deposited in KEGG database. We evaluated 26 quinone reductases, 5 quinol:electron carriers oxidoreductases and 18 terminal electron acceptor reductases. We further included in the analyses enzymes performing redox or decarboxylation driven ion translocation, ATP synthase and transhydrogenase and we also investigated the electron carriers that perform functional connection between the membrane complexes, quinones or soluble proteins. Our results bring a novel, broad and integrated perspective of membrane bound respiratory complexes and thus of the several energetic metabolisms of living systems. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi.

During the last decade, several studies have shown that mitochondrial parameters, such as integrity, respiratory activity, membrane potential and ROS production are intimately linked with sperm quality. Given the limitations of conventional semen analyses in terms of predicting male fertility, an increasing number of studies are focusing on the characterization of sperm mitochondria in order to more accurately assess sperm functionality. Moreover, mitochondria from several organs, such as the liver, have been described as a powerful screening tool for drug safety, being an easy in vitro model to assess the toxicity of distinct families of compounds. Given that mitochondrial functionality is intimately related to sperm homeostasis, it has become important to understand how compounds, ranging from dietary supplements, environmental pollutants, dependency-inducing drugs to pharmacological agents (such as erectile dysfunction-targeted drugs and male contraceptives) affect sperm mitochondrial function. In this review, we discuss studies describing the effects of various chemical agents on spermatozoa, with particular emphasis on mitochondrial function. From the extensive literature analyzed, we conclude that in some cases the role of sperm mitochondria as putative predictors of sperm functionality is very obvious, while in others further studies are needed to clarify this issue.

The reduced number of animals in most wild felid populations implies a loss of genetic diversity. The death of juveniles, prior to the production of mature sperm, represents a loss of potential genetic contribution to future populations. Since 2011 mouse testicular organ culture has introduced an alternative mechanism to produce sperm in vitro from immature tissue. However, extension of this technology to other species has remained limited. We have used the domestic cat (Felis catus) as a model for wild felids to investigate spermatogenesis initiation and regulation, with the mouse serving as a control species. Testicular tissue fragments were cultured in control medium or medium supplemented with knockout serum replacement (KSR), AlbuMax, beta-estradiol or AlbuMax plus beta-estradiol. Contrary to expectations, and unlike results obtained in mouse controls, no germ cell differentiation could be detected. The only germ cells observed after six weeks of culture were spermatogonia regardless of the initial stage of tubule development in the donor tissue. Moreover, the number of spermatogonia decreased with time in culture in all media tested, especially in the medium supplemented with KSR, while AlbuMax had a slight protective effect. The combination of AlbuMax and beta-estradiol led to an increase in the area occupied by seminiferous tubules, and thus to an increase in total number of spermatogonial cells. Considering all the media combinations tested the stimulus for felid germ cell differentiation in this type of system seems to be different from the mouse. Studies using other triggers of differentiation and tissue survival factors should be performed to pursue this technology for the genetic diversity preservation in wild felids.

Respiratory complex I couples NADH:quinone oxidoreduction to ion translocation across the membrane, contributing to the buildup of the transmembrane difference of electrochemical potential. H(+) is well recognized to be the coupling ion of this system but some studies suggested that this role could be also performed by Na(+). We have previously observed NADH-driven Na(+) transport opposite to H(+) translocation by menaquinone-reducing complexes I, which indicated a Na(+)/H(+) antiporter activity in these systems. Such activity was also observed for the ubiquinone-reducing mitochondrial complex I in its deactive form. The relation of Na(+) with complex I may not be surprising since the enzyme has three subunits structurally homologous to bona fide Na(+)/H(+) antiporters and translocation of H(+) and Na(+) ions has been described for members of most types of ion pumps and transporters. Moreover, no clearly distinguishable motifs for the binding of H(+) or Na(+) have been recognized yet. We noticed that in menaquinone-reducing complexes I, less energy is available for ion translocation, compared to ubiquinone-reducing complexes I. Therefore, we hypothesized that menaquinone-reducing complexes I perform Na(+)/H(+) antiporter activity in order to achieve the stoichiometry of 4H(+)/2e(-). In agreement, the organisms that use ubiquinone, a high potential quinone, would have kept such Na(+)/H(+) antiporter activity, only operative under determined conditions. This would imply a physiological role(s) of complex I besides a simple "coupling" of a redox reaction and ion transport, which could account for the sophistication of this enzyme. This article is part of a Special Issue entitled Respiratory complex I, edited by Volker Zickermann and Ulrich Brandt.

Summary Spermatogonial stem cells are being exploited in many species as a tool to recover fertility, but may also be used to manipulate the genetic pool. Whatever the purpose, these cells must be fully characterized and easily identifiable, and our goal was to improve this procedure in the domestic cat, used as an animal model for endangered felid species and for some human diseases/physiological processes. We have therefore screened several markers that might be used to distinguish and study the undifferentiated spermatogonia population in situ and in vitro via immunohistochemistry applied to tissue sections and whole mounts of the domestic cat seminiferous tubules. Our results show that, although they label the cytoplasm and nucleus of gonocytes and spermatogonia in pre-pubertal animals, PGP9.5 and FoxO1 cannot be considered markers of undifferentiated spermatogonia in adult animals, as almost all spermatogonia, namely type A and B, express these proteins. Nonetheless, the Dolichos biflorus agglutinin (DBA lectin) was able to label the cell surface and cytoplasm of a small type A spermatogonial population in the adult animals. Analysis of the number and distribution of the DBA-labeled cells showed they were present in low number, which did not vary with epithelium seminiferous stage. Morphometric analysis revealed that DBA-labeled cells present tropism to a peculiar area of the seminiferous tubules, namely the area in direct contact with Leydig cells. Whole mounts of DBA-stained seminiferous tubules revealed the arrangement of DBA-stained cells in small clones up to eight cells. Noteworthy, the clonal cells presented variable staining intensity suggesting the existence of asymmetric distribution of O-glycosylated proteins within each clone. Our results strongly suggest that the DBA lectin is a marker of undifferentiated spermatogonia in domestic cat, and illustrate the peculiar characteristics of spermatogonial stem cell development and organization in this species.

Lycopene is an important carotenoid present in the large volumes of tomato residues generated annually. Its SFE was studied here with two main objectives: optimization of operating conditions and selection of supercritical solvent (CO 2 versus ethane). Accordingly, a hybrid approach using the response surface methodology and cost of manufacturing (COM) concept was implemented to establish the best conditions independently of the type of extraction curves available. This approach provides accurate results even in the absence of well-defined periods of extraction (i.e., constant extraction rate branch and the maximum plateau). The minimum COM was 1.8 k € k g lycopene − 1 for CO 2 at 500 bar / 90 ° C / 25 kg CO 2 k g sample − 1 . At 300 bar/60 °C the supercritical ethane achieved better results due to the higher extraction rates observed, which originated shorter extraction cycles and thus greater annual productivity and lower COM. More experiments are necessary for an accurate solvent selection, since at 300 bar/60 °C the CO 2 is far from its best performance.

Sperm chromatin/DNA damage can be measured by a variety of assays. However, it has been reported that these tests may lose prognostic value in Assisted Reproductive Technology (ART) cycles when assessed in post-prepared samples, possibly due to the normalizing effect promoted by sperm preparation procedures. We have recently implemented a modified version of the Diff-Quik staining assay that allows for the evaluation of human sperm chromatin status in native samples, together with standard sperm morphology assessment. However, the value of this parameter in terms of predicting in vitro fertilization (IVF) and Intracytoplasmic sperm injection (ICSI) outcomes after sperm selection is unknown. In this study, data from 138 couples undergoing in vitro fertilization (IVF) or Intracytoplasmic sperm injection (ICSI) treatments showed that sperm chromatin integrity was significantly improved after density gradient centrifugation and swim up (p < 0.001), but no correlations were found with fertilization or embryo development rates (p > 0.05). However, sperm samples presenting lower percentages of damaged chromatin were associated with better quality (Grade I) embryos in both ART procedures (p < 0.05) and clinical pregnancy among IVF couples (p < 0.05). Furthermore, regression analysis confirmed the clinical value of Diff-Quik staining in predicting IVF (but not ICSI) clinical pregnancy (OR: 0.927, 95% CI: 0.871–0.985, p = 0.015), and a threshold value of 34.25% for this parameter was established. The proportion of IVF couples achieving a clinical pregnancy was reduced 1.9-fold when the percentage of abnormal dark staining was ≥34.25% (p = 0.05). In conclusion, the Diff-Quik staining assay provides useful information regarding ART success, particularly in IVF cycles, where some degree of ‘natural’ sperm selection may occur; but not in ICSI, where sperm selection is operator dependent. This quick and low-cost assay is suggested as an alternative method to detect sperm chromatin status in minimal clinical settings, when no other well-established and robust assays (e.g. Sperm chromatin structure assay, terminal deoxynucleotidyl transferase-mediated dUDP nick-end labelling) are available. This work was carried out, in part, in order to fulfil the requirements for a Masters Degree in Biology (A.F.S.) and a PhD Degree in Cell Biology (R.S.T.), Department of Life Sciences, University of Coimbra, Portugal. R.S.T. is a recipient of a PhD fellowship from FCT, Portugal (SFRH/BD/46002/2008). CNC funding is supported by FCT, Portugal (PEst-C/SAU/LA0001/2011).