Broad antibacterial spectrum, high oral bioavailability and excellent tissue penetration combined with safety and few, yet rare, unwanted effects, have made the quinolones class of antimicrobials one ...of the most used in inpatients and outpatients. Initially discovered during the search for improved chloroquine-derivative molecules with increased anti-malarial activity, today the quinolones, intended as antimicrobials, comprehend four generations that progressively have been extending antimicrobial spectrum and clinical use. The quinolone class of antimicrobials exerts its antimicrobial actions through inhibiting DNA gyrase and Topoisomerase IV that in turn inhibits synthesis of DNA and RNA. Good distribution through different tissues and organs to treat Gram-positive and Gram-negative bacteria have made quinolones a good choice to treat disease in both humans and animals. The extensive use of quinolones, in both human health and in the veterinary field, has induced a rise of resistance and menace with leaving the quinolones family ineffective to treat infections. This review revises the evolution of quinolones structures, biological activity, and the clinical importance of this evolving family. Next, updated information regarding the mechanism of antimicrobial activity is revised. The veterinary use of quinolones in animal productions is also considered for its environmental role in spreading resistance. Finally, considerations for the use of quinolones in human and veterinary medicine are discussed.
Seismic risk management in urban areas requires accurate prediction of the expected seismic hazard. The seismic design standards in the world provide the seismic design spectra (DS). These are ...crucial for estimating seismic forces on a structure, are typically derived from theoretical models in deterministic or probabilistic seismic hazard studies, especially for bedrock soils. Characterizing soil dynamic amplification frequencies or periods is necessary to establish site-specific design spectra (DSsite). Geotechnical and geophysical studies, along with environmental vibration records, determine soil stratigraphy characteristic features and their dominant frequency or period. These parameters improve our understanding of seismic wave behavior from bedrock to surface soil during earthquakes. This article details the utilization of geotechnical, geophysical studies, and environmental vibration records to estimate DSsite in accordance with Mexican seismic regulation and examines the cost–benefit aspects of using the Dssite in optimizing the structural design of a medium-rise steel building in southeastern Mexico, characterized by soft soil and a moderate seismic hazard. The case study demonstrates an 18% cost savings in the structural elements of the building by employing the DSsite with more rational spectral ordinates for study site.
During strong earthquakes, structural damage usually occurs, resulting in a degradation of the overall stiffness of the affected structures. This degradation produces a modification in the dynamic ...properties of the structures, for instance, in the fundamental period of vibration (T1). Hence, the variation of T1 could be used as an indicator of seismic structural damage. In this article, a seismic damage assessment in four generic typologies of steel buildings was carried focused on verifying the variation of T1. To do so, several seismic damage states were calculated using the maximum inter-story drift ratio, MIDR, and following the Risk-UE guidelines. Then, a series of probabilistic nonlinear static analyses was implemented using Monte Carlo simulations. The probabilistic approach allows one to vary the main mechanical properties of the buildings, thus analyzing in this research 4000 buildings (1000 building samples for each of the four generic typologies). The variation of T1 was estimated using the capacity spectrum, and it was related to the MIDR for each damage state. As a main result of this study, the expected variation of T1 for several damage states is provided. Finally, a proposal for a seismic damage preventive “semaphore” and fragility curves are presented. These results may be useful as parameters or criteria in the evaluation of on-site structural monitoring for steel buildings.
Few sclerophyllous plants from the central coast of Chile have been systematically studied. This work describes the phytochemical composition and antimicrobial properties of
Pers. (sin.
), a shrub ...found in the first line and near the Pacific coast.
has been traditionally used by indigenous inhabitants of today's central Chile for its medicinal properties. Few reports exist regarding the phytochemistry characterization and biological activities of
. A hydroalcoholic extract of
was prepared from leaves and small branches. Qualitative phytochemical characterization indicated the presence of alkaloids, steroids, terpenoids, flavonoids, phenolic, and tannin compounds. The antimicrobial activity of this extract was assessed in a panel of microorganisms including Gram-positive bacteria, Gram-negative bacteria, and pathogenic yeasts. The extract displayed an important antimicrobial effect against Gram-positive bacteria,
and
but not against Gram-negatives, for which an intact Lipopolysaccharide is apparently the determinant of resistance to
extracts. The hydroalcoholic extract was then fractionated through a Sephadex LH-20/methanol-ethyl acetate column. Afterward, the fractions were pooled according to a similar pattern visualized by TLC/UV analysis. Fractions obtained by this criterion were assessed for their antimicrobial activity against
. The fraction presenting the most antimicrobial activity was HPLC-ESI-MS/MS, obtaining molecules related to caffeoylquinic acid, dicaffeoylquinic acid, and quercetin, among others. In conclusion, the extracts of
showed strong antimicrobial activity, probably due to the presence of metabolites derived from phenolic acids, such as caffeoylquinic acid, and flavonoids, such as quercetin, which in turn could be responsible for helping with wound healing. In addition, the development of antimicrobial therapies based on the molecules found in
could help to combat infection caused by pathogenic yeasts and Gram-positive bacteria, without affecting the Gram-negative microbiota.
Almost a decade ago, the Mexican government targeted to establish environmental water reserves (EWR)—a volume of water allocated for ecological protection based on the Environmental Flow Mexican Norm ...(eflows, NMX-AA-159-SCFI-2012, ratified in 2017)—in strategic low-pressured for water use and high conservation importance river basins throughout the country. To date, 12 EWRs have been declared for up to 50 years, which encompass 295 river basins and ~55% of the national mean annual runoff (MAR). In this article, we conducted a quality evaluation of the EWRs established. First, the EWR level was analyzed against the MAR and according to wider hydrological conditions. The EWR fulfillment was evaluated by comparing the volumes enacted against the theoretical (Norm implementation). Our findings revealed that independently of individual and regional water use and conservation merits context, ~75% of the EWRs met theoretical volumes at least at an acceptable level, of which medians ranged from 24% to 73% MAR (natural parametrization and A–D environmental objectives). These outcomes prove the usefulness and consistency of the Mexican strategic hierarchical approach for eflow assessments. We aim for them to be considered as the baseline for future on-site eflow implementation and environmental water policy assessments, to show the nationwide potential benefits for protecting free-flowing rivers and to encourage a regional escalation of the strategy.
In this research, the use of the pre-wetting technique is proposed as an ecological alternative to reduce water absorption in waste oyster shells used in the production of masonry mortar as a partial ...substitute for natural sand. An experimental study was conducted to assess the properties in both the fresh and hardened states of masonry mortars. Two mortar groups were prepared based on a control mixture, with natural aggregate replaced by crushed oyster shell (COS) in varying proportions. In one group, the COS was pre-wetted, while in the other group, the COS was used at its natural moisture content. The experimental results demonstrated that the pre-wetting process aided in reducing the water–cement ratio (w/c) in the mortar mixture, thereby improving its properties. In both mortar groups, favorable results were observed with respect to capillary water absorption. Although the compressive strength was affected by the incorporation of COS, pre-wetted mortars with substitutions of up to 30% achieved the reference value established in this research. The pre-wetting process proves to be a straightforward and cost-effective technique; it is environmentally friendly and will contribute to decreasing the accumulation of COS in landfills, thereby safeguarding natural material reserves.
In this article, a systematic procedure to derive equivalent circuit networks accurately reproducing the frequency response of the input impedance of magnetic cores in a broad frequency range is ...presented. The proposed procedure foresees to represent the effective complex permeability spectra of a magnetic core (i.e., the permeability resulting from the superposition of intrinsic material properties and effects due to structural features of the core) by a high-order Debye series expansion, which is subsequently synthesized into suitable Foster and Cauer networks. Such networks can be implemented in any circuit simulator, and are particularly favorable for time-domain transient simulation since they can be easily combined with hysteresis models. Two nanocrystalline tape-wound cores and a commercial bulk current injection probe are used as test cases to prove the effectiveness of the proposed method both in terms of accuracy and ease of implementation.
ObjectivesAcquired thrombotic thrombocytopenic purpura (aTTP) is a rare hematological disease whose clinical management includes caplacizumab along with plasma exchange and immunosuppression, ...according to international guidelines. Caplacizumab has been available in Colombia since 2022. This study seeks to determine the therapeutic classification of caplacizumab according to the methodology of the Instituto de Evaluación Tecnológica en Salud.MethodsThe classification was carried out through a deliberative process following the modified Delphi technique, with a panel of experts, made up of four hemato-oncologists, a pharmaceutical chemist, and a patient. The results of effectiveness and safety obtained through a systematic review, therapeutic thresholds (clinical significance), and degree of acceptability (willingness to use the technology) were used for the classification.ResultsFourteen effectiveness and safety outcomes were submitted for the classification process. Caplacizumab showed clinical significance for some effectiveness outcomes, was not considered inferior in terms of safety, and displayed acceptability of use. Through consensus, the panel determined that caplacizumab plus the standard regimen is superior to the standard regimen in terms of treatment response and composite outcome, and no different for the other effectiveness and safety outcomes. Likewise, in overall terms, the panel determined that caplacizumab together with the standard regimen is superior to the standard regimen.ConclusionTreatment with caplacizumab together with the standard regimen was considered superior to the standard regimen for the treatment of patients with aTTP, as it showed clinically significant benefits in critical outcomes for decision making, and a safety profile no different to its comparator.
Urban development decreases infiltration, increases the runoff velocity, and reduces the concentration times. This situation increases the flood risk in urban watersheds, which represent a management ...challenge for urban communities and authorities. To increase the resilience of communities due to modifications of the hydrological cycle produced by climate change and urban development, a methodology is proposed to delineate flood-prone areas in urban basins. This methodology is implemented in an urban subbasin of Culiacan, Mexico, and is based on stream order. A high-resolution digital elevation model was used, which was validated independently through a photogrammetric flight with an unmanned aerial vehicle and ground control points obtained with GNSS (global navigation satellite systems) receivers. Morphometric parameters related to geometry, shape, relief, and drainage network aspects of the subbasin were determined and analyzed. Then, flood-prone area zonation was carried out based on stream-order classification and flow direction. Fieldwork was also carried out for the inspection of the sewage network conditions. This methodology simplifies the identification of the flood-prone areas in urban subbasins without carrying out complex hydraulic calculations.
Mexican oregano Poliomintha longiflora Gray located in the municipality of Higueras, Nuevo Leon, Mexico was collected during the autumn (September, OCO), winter (January, OCI) and summer (June, OCV) ...seasons, under cultivation conditions. It was also collected in wild conditions during the autumn (OSO). Essential oil (EO) was extracted from leaves and the color, refractive index and density were reported. The EO yield, antioxidant activity by ORAC assay, thymol and carvacrol concentration and antibacterial activity were statistically compared (p-value = 0.05). Among the various harvests, the highest EO yield, antioxidant activity, thymol and carvacrol content and antibacterial activity against Salmonella Typhi were observed in leaves harvested in autumn. In order to compare wild oregano with cultivated oregano, analyses were performed in the season with the highest essential oil yield and antioxidant activity, recorded in autumn. The main difference found was the ratio of thymol:carvacrol in wild oregano oil, which was 1:8.6, while in cultivated oregano, it was approximately 1:2, which was maintained in all three seasons. The EO on wild conditions showed the best antibacterial activity in Salmonella Typhi. On the other hand, wild and cultivated oregano showed similar antioxidant activity. One advantage of the use of cultivated oregano is that its supply is guaranteed, in contrast to that of wild oregano.
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