The COVID-19 pandemic and non-COVID-19 healthcare utilization in Mexico.

OBJECTIVES: This study aimed to analyze the effects of the COVID-19 pandemic on non-COVID-19 healthcare utilization in Mexico, including oral health, mental health, communicable disease visits, health checkups, chronic degenerative disease visits, postpartum care, prenatal care, and family planning visits. STUDY DESIGN: This was a retrospective ecological analysis during the COVID-19 pandemic. During the pandemic, the Mexican government recommended non-essential consultations be suspended or rescheduled to accommodate the new demand for healthcare services from COVID-19 patients. METHODS: This study uses administrative data from Mexico's Ministry of Health from January 2017 to December 2022. These data cover 14,299 consultation units and 775 hospitals from the 32 Mexican States, all of which are public institutions. A difference-in-differences strategy and an event study specification are used to study the impacts of the pandemic on non-COVID-19 healthcare utilization. RESULTS: The findings reveal a decrease in the utilization of all healthcare services: oral health (69%), mental health (27%), communicable diseases (46%), chronic degenerative diseases (36%), health checkups (62%), family planning (45%), prenatal care (36%), and postpartum care (44%). Furthermore, the event study indicates that most services follow a U-shaped trend, although only mental health services clearly return to prepandemic levels. The remainder of services remain below prepandemic levels at the end of 2022. CONCLUSIONS: The 2020 pandemic had detrimental effects on non-COVID-19 healthcare utilization. The healthcare interruptions will likely impact short- and long-term morbidity and mortality. Programs intended to remediate these negative consequences may be of interest to public health policymakers.

Characterization of the hierarchical architecture and micromechanical properties of walnut shell (Juglans regia L.).

In the present work a comprehensive characterization of the hierarchical architecture of the walnut shell (Juglans regia L.) was carried out using scanning electron microscopy (SEM), atomic force microscopy (AFM) and confocal laser scanning microscopy (CLSM). Furthermore, micromechanical properties (hardness, HIT and elastic modulus, EIT) of plant tissues were evaluated at cell wall level by applying the instrumented indentation technique (IIT). The complex architecture of the material was described in terms of four hierarchical levels (HL): endocarp (H1), plant tissues (H2), plant cells (H3) and cell wall (H4). Our findings revealed that the walnut shell consists of a multilayer structure (sclerenchyma tissue, ST; interface tissue, IT; porous tissue, PT; and flattened parenchyma tissue, FPT), where differences in the microstructure and composition of plant tissues generate parallel gradients along the cross-section. The indentation tests showed a functional gradient with a sandwich-like configuration, i.e., a lightweight and soft layer (PT, HIT = 0.04 GPa) is located between two dense and hard layers (ST, HIT = 0.33 GPa; FPT, HIT = 0.28 GPa); where additionally there is an interface between ST and PT (IT, HIT = 0.16 GPa). This configuration is a successful strategy designed by nature to improve the protection of the kernel by increasing the strength of the shell. Therefore, the walnut shell can be considered as a functionally graded material (FGM), which can be used as bioinspiration for the design of new functional synthetic materials. In addition, we proposed some structure-property-function relationships in the whole walnut shell and in each of the plant tissues.

Effect of calcium oxalate crystals on the micromechanical properties of sclerenchyma tissue from the pecan nutshell (Carya illinoinensis).

The objective of this study was to evaluate the effect of the presence of calcium oxalate (CaOx) crystals on the micromechanical properties of sclerenchyma tissue from the pecan nutshell (Carya illinoinensis). The microstructure of the cross-section nutshell was examined using light microscopy (LM) and atomic force microscopy (AFM). Using an instrumented indentation system, indentation tests with maximum loads of 500 mN were made on the biological material where the variables studied were the number of crystals present in the evaluated area and the size of individual crystals. Microscopic analysis revealed that the pecan nutshell consists of sclerenchyma tissue with multiple CaOx crystals randomly distributed throughout the material, exhibiting prismatic shapes and various sizes. The results of the indentation tests showed that the examined areas where there were crystals (1, 2 or up to 3) presented values of hardness and elastic modulus significantly higher (P < 0.05) compared to the sclerenchyma (without crystals). Likewise, there were no significant differences (P > 0.05) between the values of the micromechanical properties of the areas evaluated as a function of the number of crystals. On the other hand, it was observed that the size of the crystals did not show a direct correlation with the mechanical properties evaluated as expected. In conclusion, the biomineralization phenomenon is a successful strategy designed by nature to improve the rigidity of the pecan nutshell, where the CaOx crystals strengthen the structure by increasing the micromechanical properties.

Effect of pepper extracts on the viability kinetics, topography and Quantitative NanoMechanics (QNM) of Campylobacter jejuni evaluated with AFM.

Campylobacter jejuni is a pathogen bacterium that causes foodborne gastroenteritis in humans. However, phenolic compounds extracted from natural sources such as capsicum pepper plant (Capsicum annuum L. var. aviculare) could inhibit the growth of C. jejuni. Therefore, different extracts were prepared using ultrasonic extraction (USE), conventional extraction (CE) and thermosonic extraction (TSE). C. jejuni was then exposed to chili extracts to examine the antimicrobial effect and their growth/death bacterial kinetics were studied using different mathematical models. Atomic force microscopy was applied to investigate the microstructural and nanomechanical changes in the bacteria. Extracts obtained by TSE had the highest phenolic content (4.59 ± 0.03 mg/g of chili fresh weight [FW]) in comparison to USE (4.12 ± 0.05 mg/g of chili FW) and CE (4.28 ± 0.07 mg/g of chili FW). The inactivation of C. jejuni was more efficient when thermosonic extract was used. The Gompertz model was the most suitable mathematical model to describe the inactivation kinetics of C. jejuni. Roughness and nanomechanical analysis performed by atomic force microscopy (AFM) provided evidence that the chili extracts had significant effects on morphology, surface, and the reduced Young's modulus of C. jejuni. The novelty of this work was integrating growth/death bacterial kinetics of C. jejuni using different mathematical models and chili extracts, and its relationship with the morphological, topographic and nanomechanical changes estimated by AFM.

Efficacy and safety of trifluridine/tipiracil in third-line and beyond for the treatment of patients with metastatic colorectal cancer in routine clinical practice: patterns of use and prognostic nomogram.

INTRODUCTION: Trifluridine/tipiracil combination has shown a benefit over placebo in the treatment of patients with chemorefractory metastatic colorectal cancer (mCRC). We evaluated the efficacy and safety of this combination in the real-life setting at eight Galician centers in Spain. PATIENTS AND METHODS: This is a retrospective study of a cohort of patients with mCRC in treatment with trifluridine/tipiracil within usual clinical practice who have been previously treated or are not considered candidates for treatment with available therapies. RESULTS: A total of 160 mCRC patients were included. Our data showed that 11.9% of patients achieved disease control. Median progression-free survival was 2.75 months; at 5.66 months follow-up, median overall survival was 7.94 months. Asthenia and neutropenia (48.1% both) were the most frequent adverse events. Overall survival was lower in patients with ECOG 2, multiple metastatic sites, platelets count 350,000/µl, alkaline phosphatase > 500 IU/l, and carcinoembryonic antigen > 10 ng/ml. CONCLUSION: The results of this study confirm the efficacy and safety of trifluridine/tipiracil in chemorefractory mCRC patients. However, patients in clinical practice differ from patients in clinical trials. Due to this, prognostic factors have special importance to offer the best therapeutic approach.

Evaluation of Nanomechanical Properties of Tomato Root by Atomic Force Microscopy.

Here, different tissue surfaces of tomato root were characterized employing atomic force microscopy on day 7 and day 21 of growth through Young's modulus and plasticity index. These parameters provide quantitative information regarding the mechanical behavior of the tomato root under fresh conditions in different locations of the cross-section of root [cell surface of the epidermis, parenchyma (Pa), and vascular bundles (Vb)]. The results show that the mechanical parameters depend on the indented region, tissue type, and growth time. Thereby, the stiffness increases in the cell surface of epidermal tissue with increasing growth time (from 9.19 ± 0.68 to 13.90 ± 1.68 MPa) and the cell surface of Pa tissue displays the opposite behavior (from 1.74 ± 0.49 to 0.48 ± 0.55); the stiffness of cell surfaces of Vb tissue changes from 10.60 ± 0.58 to 6.37 ± 0.53 MPa, all cases showed a statistical difference (p < 0.05). Viscoelastic behavior dominates the mechanical forces in the tomato root. The current study is a contribution to a better understanding of the cell mechanics behavior of different tomato root tissues during growth.

Study of the porosity of calcified chicken eggshell using atomic force microscopy and image processing.

In this work, the porosity of the layers of calcified chicken eggshell (vertical crystal layer VCL, palisade layer PL and mammillary layer ML) was evaluated using atomic force microscopy (AFM) and image processing (IP). AFM topographic images were obtained from different locations for each layer and along the cross-section of calcified eggshell. Roughness parameters, surface area values, pore size and shape, surface porosity, area occupied by pores and pore density were obtained from AFM and IP. It was observed that the thickest layer (PL) exhibited the highest degree of porosity (surface porosity = 2.75 ± 1.68%, pore density = 162 ± 60 pores/µm2) when compared to the other two layers. In general, the pores located in all layers ("bubble pores") had circular shape and similar sizes. Measurements revealed a porosity gradient along the cross-section which varied with position, i.e., increasing surface porosity from the VCL towards the region of the PL closer to the ML, and decreasing surface porosity from this location towards the ML innermost surface. This suggests that the calcified eggshell has a sandwich-like structure where porosity may influence gas exchange and mechanical properties. The combination of AFM with IP presented here provides a simple and precise method to study porosity in calcified chicken eggshell, and this methodology could be used to examine other types of porous biological materials.

Morphological and micromechanical characterization of calcium oxalate (CaOx) crystals embedded in the pecan nutshell (Carya illinoinensis).

The morphology and micromechanical properties of the mineral crystals embedded in the pecan nutshell (Carya illinoinensis) were characterized. Qualitative and quantitative morphological analyses carried out revealed that the crystals were comprised of calcium oxalate (CaOx) and have a wide range of sizes, with prismatic shapes, distributed heterogeneously in the sclerenchyma tissue. From indentation tests, it was found that CaOx crystals are stiffer structures compared to stone cells (sclerenchyma tissue), showing hardness and elastic modulus values of 0.53 ±â€¯0.19 GPa and 9.4 ±â€¯1.80 GPa, respectively. Additionally, the values of fracture toughness (0.08 ±â€¯0.02 MPa m0.5) and the brittleness index (9336 m-0.5) revealed that these types of structures are extremely brittle. The results obtained suggest that the main function of the CaOx crystals is to provide structural support to tissue. The presented methodology demonstrates the potential of the instrumented indentation technique (IIT) for in situ micromechanical characterization of mineral crystals located in plant tissues.

Numerical study of the hydrodynamic drag force in atomic force microscopy measurements undertaken in fluids.

When atomic force microscopy (AFM) is employed for in vivo study of immersed biological samples, the fluid medium presents additional complexities, not least of which is the hydrodynamic drag force due to viscous friction of the cantilever with the liquid. This force should be considered when interpreting experimental results and any calculated material properties. In this paper, a numerical model is presented to study the influence of the drag force on experimental data obtained from AFM measurements using computational fluid dynamics (CFD) simulation. The model provides quantification of the drag force in AFM measurements of soft specimens in fluids. The numerical predictions were compared with experimental data obtained using AFM with a V-shaped cantilever fitted with a pyramidal tip. Tip velocities ranging from 1.05 to 105 µm/s were employed in water, polyethylene glycol and glycerol with the platform approaching from a distance of 6000 nm. The model was also compared with an existing analytical model. Good agreement was observed between numerical results, experiments and analytical predictions. Accurate predictions were obtained without the need for extrapolation of experimental data. In addition, the model can be employed over the range of tip geometries and velocities typically utilized in AFM measurements.

Physical and structural characterisation of zein and chitosan edible films using nanotechnology tools.

The use of composite edible films made from biopolymers has attracted interest as a way to reduce pollution and recycling problems; however, the relation between barrier, mechanical and structural properties of the films have been scarcely studied. The aim of this work was to evaluate composite zein-chitosan edible films by applying common nanotechnology tools and to relate the results to zein concentration and film structural changes. Rougher, more elastic, and less hard film structures with better water vapour barrier properties were obtained using larger zein concentrations. Raman spectroscopy exhibited unexpected interactions, as indicated by the disappearance of the thiol groups of cysteine in the zein films and the appearance of O=S=O and C-O-S groups in the blended materials in conjunction with the disappearance of zein ε-amino and -NH2 functional groups in the zein film samples, thereby confirming changes in the blended film structure. Zein concentration presented linear correlations with water vapour permeability (R=-0.978) and film roughness (R=0.929). The composite films presented better barrier and mechanical properties than single ingredient films. This information shows the benefit of using protein-polysaccharide blends to prepare edible films.

Recruitment of the sensorimotor cortex--a developmental FMRI study.

INTRODUCTION: The growing mastery of motor tasks is one of the most visible changes in the developing child. The cortex is known to play a central role in learning, planning, and performance of motor tasks. We investigated the age dependency of motor cortex activation using functional magnetic resonance imaging (fMRI). METHODS: Thirty-two right-handed subjects were studied: 11 children (median age 9 years, range 6 - 10 years), 10 adolescents (median age 13 years, range 11 - 15 years), and 11 adults (median age 27 years, range 23 - 42 years). The subjects performed a simple, paced unilateral motor task (repetitive squeezing of a ball with the right hand). Also, we set up a control experiment (visual stimulation using an alternating checkerboard pattern) in which no age-related differences were expected. RESULTS: Compared to children, adults showed significantly increased activation of the bilateral sensorimotor cortex, parietal areas, the supplementary motor area, and the cerebellum. In the visual stimulation experiment there were no age-related differences. CONCLUSION: Children show a significant difference in the degree of cortical activation compared to adults when performing a simple motor task. The change in fMRI activation patterns may reflect a maturation process of primary and secondary motor areas.

[The prognostic value of computerized tomography in acute aneurysmal subarachnoid haemorrhages]. / Valor pronóstico de la tomografía computarizada en la hemorragia subaracnoidea aneurismática aguda.

INTRODUCTION AND DEVELOPMENT: The radiological diagnosis of subarachnoid haemorrhages (SAH) is based fundamentally on studies using computerised tomography, although magnetic resonance imaging has also been proved to be highly sensitive. Spontaneous SAH is essentially due to the rupture of a cerebral aneurysm. The distribution of the SAH and the presence of associated haemorrhagic lesions are useful for developing a suspicion as to the exact whereabouts of the aneurysm causing the SAH. CONCLUSIONS: SAH is still linked to a poor prognosis despite the progress made in its diagnosis and treatment. Several radiological factors have been reported as being associated to a poorer prognosis: 1. The risk of complications is related to the extension of the SAH. The most widely accepted classification for determining the extension is the one put forward by Fisher. The higher grades III and IV are linked to a higher rate of morbidity and mortality. 2. SAH that is situated in the perimesencephalic cisterns is linked to a low risk of being of aneurysmal origin and to a good progression. 3. A size above 10 mm is linked to a poorer progression. 4. Finally, the appearance of any of the possible complications (vasospasm, rebleeding, haemorrhage, edema) is also linked to a poorer prognosis.

Valor pronóstico de la tomografía computarizada en la hemorragia subaracnoidea aneurismática aguda / The prognostic value of computerised tomography in acute aneurysmal subarachnoid haemorrhages

Introducción y desarrollo. El diagnóstico radiológico de la hemorragia subaracnoidea (HSA) se basa fundamentalmente en la realización de un estudio de tomografía computarizada, aunque se ha demostrado la alta sensibilidad de los estudios de resonancia magnética. La HSA espontánea se debe fundamentalmente a la ruptura de un aneurisma cerebral. La distribución de la HSA y la presencia de lesiones hemorrágicas asociadas es útil para sospechar la localización del aneurisma causante de la HSA. Conclusiones. La HSA se asocia todavía a un mal pronóstico, pese a los avances en su diagnóstico y tratamiento. Se han descrito diversos factores radiológicos asociados a un peor pronóstico: 1. El riesgo de complicaciones guarda relación con la extensión de la HSA, y la clasificación más aceptada para determinar la extensión es la propuesta por Fisher. Los grados mayores III y IV se asocian a una peor morbimortalidad. 2. La HSA localizada en las cisternas perimesencefálicas se asocia a un bajo riesgo de origen aneurismático y a una buena evolución. 3. Un tamaño de más de 10 mm se asocia también a una peor evolución. 4. Finalmente, la aparición de cualquiera de las complicaciones posibles (vasoespasmo, resangrado, hemorragia, edema) se asocia también a un peor pronóstico (AU)

Introduction and development. The radiological diagnosis of subarachnoid haemorrhages (SAH) is based fundamentally on studies using computerised tomography, although magnetic resonance imaging has also been proved to be highly sensitive. Spontaneous SAH is essentially due to the rupture of a cerebral aneurysm. The distribution of the SAH and the presence of associated haemorrhagic lesions are useful for developing a suspicion as to the exact whereabouts of the aneurysm causing the SAH. Conclusions. SAH is still linked to a poor prognosis despite the progress made in its diagnosis and treatment. Several radiological factors have been reported as being associated to a poorer prognosis: 1. The risk of complications is related to the extension of the SAH. The most widely accepted classification for determining the extension is the one put forward by Fisher. The higher grades III and IV are linked to a higher rate of morbidity and mortality. 2. SAH that is situated in the perimesencephalic cisterns is linked to a low risk of being of aneurysmal origin and to a good progression. 3. A size above 10 mm is linked to a poorer progression. 4. Finally, the appearance of any of the possible complications (vasospasm, rebleeding, haemorrhage, edema) is also linked to a poorer prognosis (AU)

[Use of Boyer's score in the differential diagnosis of meningitis]. / Aplicación del "score" de Boyer para el diagnóstico diferencial de las meningitis.

Authors have studied reliability of Boyer's score for diagnosis of bacterial versus aseptic meningitis. This score is based upon clinical and biological data easily available in few hours since the patient's admission to hospital. They their have reviewed all cases of meningitis in hospital during the last four years. Boyer's score was very useful and its specificity (100%) and sensitivity (96,50%) were very high. Authors consider this test convenient and reliable for the presumptive diagnosis of the type of meningitis with its' therapeutic implications.

[Clinical-therapeutical correlations in meningococcal infection: prophylactic heparin therapy (author's transl)]. / Correlaciones clinicoterapéuticas en la infección meningocócica (heparinoterapia profiláctica).

A number of 241 patients with meningococcal infection, treated between 1972 and 1978, is analysed. Some new therapeutic patterns are established based on the application of the prognosis score of Stiehm. With these patterns consisting in the use of volume expansors with anti-aggregating properties and low dosage prophylactic heparin administration, authors have considerably improved their results reported in 1972, succeeding in diminishing the global mortality to 3.73%, a figure inferior to that of all known series to date.

[Congenital cystic adenomatoid malformation of the lung with systemic circulation (author's transl)]. / Malformación adenomatoidea quística pulmonar congénita con circulación sistémica.

A new observation of CCAML which systemic circulation is presented. At this occasion authors update literature review published in 1973. The total number of cases reported is 78 which our case has to be added. The existence of a systemic artery has only been demonstrated previously in three patients.