scholarly journals Within a Nanometer of your Life

2001 ◽  
Vol 123 (08) ◽  
pp. 54-58 ◽  
Author(s):  
Allen J. Menezes ◽  
Vik J. Kapoor ◽  
Vijay K. Goel ◽  
Brent D. Cameron ◽  
Jian-Yu Lu

This article reviews advances in semiconductor manufacturing techniques that are bringing medicine closer to cures and treatments that have eluded researchers working on the macro scale. An orthopaedic implant company, Implex Corp. of Allendale, New Jersey, has developed spinal fusion devices for the cervical, thoracic, and lumbar spine using a novel biomaterial called Hedrocel Trabecular Metal. According to Implex, Hedrocel, which has a porous structure and mechanical properties like bone, can be formed or machined into complex shapes. Implex has developed hip and knee reconstruction devices made wholly or in part of Hedrocel. The spinal implants are in commercial use in Europe and are undergoing clinical trials in the United States. By studying fluid samples at the cellular level, the system can diagnose the physical and chemical status of cells to detect disease at an early stage. Nanopore fabrication technology is used to make microcapsules for implanting neurons in the brain. Once the capsules are implanted, the neurons are electrically stimulated to release neurotransmitters. Disorders where basic neurosecretory cells are missing or damaged can be treated using nanopore technology.

Author(s):  
Rika M. Wright ◽  
K. T. Ramesh

Traumatic brain injury (TBI) is a debilitating injury that affects more than 1.4 million people in the United States each year. Of the incidences of TBI, diffuse axonal injury (DAI) accounts for the second largest percentage of deaths. DAI is caused by inertial loads to the head, and it is characterized by damage to neurons. Despite the extensive research on DAI, the injury mechanisms associated with the pathology are still poorly understood. The crucial link between the inertial forces to the head at the macroscale and the resulting damage at the cellular level has yet to be explained. An integral step to understanding this coupling between mechanical forces and the functional damage of neurons is the development of an analytical model that accurately represents the mechanics of brain deformation under inertial loads. It has been noted in clinical and experimental studies that the most common injury location of DAI is within the deep white matter of the brain. Structures such as the splenium of the corpus callosum are cited as being highly susceptible to damage [1]. Although numerous brain tissue models have been proposed, few models account for the anisotropic nature of white matter in the brain. As a first step in developing an anisotropic model for white matter, the effect of the invariant terms in a strain energy function for white matter is analyzed.


Author(s):  
M. Sato ◽  
Y. Ogawa ◽  
M. Sasaki ◽  
T. Matsuo

A virgin female of the noctuid moth, a kind of noctuidae that eats cucumis, etc. performs calling at a fixed time of each day, depending on the length of a day. The photoreceptors that induce this calling are located around the neurosecretory cells (NSC) in the central portion of the protocerebrum. Besides, it is considered that the female’s biological clock is located also in the cerebral lobe. In order to elucidate the calling and the function of the biological clock, it is necessary to clarify the basic structure of the brain. The observation results of 12 or 30 day-old noctuid moths showed that their brains are basically composed of an outer and an inner portion-neural lamella (about 2.5 μm) of collagen fibril and perineurium cells. Furthermore, nerve cells surround the cerebral lobes, in which NSCs, mushroom bodies, and central nerve cells, etc. are observed. The NSCs are large-sized (20 to 30 μm dia.) cells, which are located in the pons intercerebralis of the head section and at the rear of the mushroom body (two each on the right and left). Furthermore, the cells were classified into two types: one having many free ribosoms 15 to 20 nm in dia. and the other having granules 150 to 350 nm in dia. (Fig. 1).


Author(s):  
Mehmet Sarikaya ◽  
Ilhan A. Aksay

Biomimetics involves investigation of structure, function, and methods of synthesis of biological composite materials. The goal is to apply this information to the design and synthesis of materials for engineering applications.Properties of engineering materials are structure sensitive through the whole spectrum of dimensions from nanometer to macro scale. The goal in designing and processing of technological materials, therefore, is to control microstructural evolution at each of these dimensions so as to achieve predictable physical and chemical properties. Control at each successive level of dimension, however, is a major challenge as is the retention of integrity between successive levels. Engineering materials are rarely fabricated to achieve more than a few of the desired properties and the synthesis techniques usually involve high temperature or low pressure conditions that are energy inefficient and environmentally damaging.In contrast to human-made materials, organisms synthesize composites whose intricate structures are more controlled at each scale and hierarchical order.


2017 ◽  
Vol 23 (1) ◽  
Author(s):  
C.A. JAWALE

Ovarian maturation by neurosecretory cells in the brain of freshwater crab, Barytelphusa cunicularis have been examined. The histological scrutiny of the brain of Barytelphusa cunicularis related with three types (A, B and C) of neurosecretory cells, which are classified on the basis of size, shape and tinctorial characters. All these types of cells marked annual cyclic changes of cytoplasmic material in association with ovarian cycle. The activity of these cells has been correlated with the ovarian cycle. They are distinguishable by their size, nature locations, shape, nucleus position, cell measure and the secretory product in the cytoplasm. The result indicates that the neurosecretory A, B and C cells of the brain seen involved in the process of mating ovulation. The neurosecretory materials staining intensity index of these cells is described.


Author(s):  
М.М. Руденок ◽  
А.Х. Алиева ◽  
А.А. Колачева ◽  
М.В. Угрюмов ◽  
П.А. Сломинский ◽  
...  

Несмотря на очевидный прогресс, достигнутый в изучении молекулярно-генетических факторов и механизмов патогенеза болезни Паркинсона (БП), в настоящее время стало ясно, что нарушения в структуре ДНК не описывают весь спектр патологических изменений, наблюдаемых при развитии заболевания. В настоящее время показано, что существенное влияние на патогенез БП могут оказывать изменения на уровне транскриптома. В работе были использованы мышиные модели досимптомной стадии БП, поздней досимптомной и ранней симптомной (РСС) стадиями БП. Для полнотранскриптомного анализа пулов РНК тканей черной субстанции и стриатума мозга мышей использовались микрочипы MouseRef-8 v2.0 Expression BeadChip Kit («Illumina», США). Полученные данные указывают на последовательное вовлечение транскриптома в патогенез БП, а также на то, что изменения на транскриптомном уровне процессов транспорта и митохондриального биогенеза могут играть важную роль в нейродегенерации при БП уже на самых ранних этапах. Parkinson’s disease (PD) is a complex systemic disease, mainly associated with the death of dopaminergic neurons. Despite the obvious progress made in the study of molecular genetic factors and mechanisms of PD pathogenesis, it has now become clear that violations in the DNA structure do not describe the entire spectrum of pathological changes observed during the development of the disease. It has now been shown that changes at the transcriptome level can have a significant effect on the pathogenesis of PD. The authors used models of the presymptomatic stage of PD with mice decapitation after 6 hours (6 h-PSS), presymptomatic stage with decapitation after 24 hours (24 h-PSS), advanced presymptomatic (Adv-PSS) and early symptomatic (ESS) stages of PD. For whole transcriptome analysis of RNA pools of the substantia nigra and mouse striatum, the MouseRef-8 v2.0 Expression BeadChip Kit microchips (Illumina, USA) were used. As a result of the analysis of whole transcriptome data, it was shown that, there are a greater number of statistically significant changes in the tissues of the brain and peripheral blood of mice with Adv-PSS and ESS models of PD compared to 6 h-PSS and 24 h-PSS models. In general, the obtained data indicate the sequential involvement of the transcriptome in the pathogenesis of PD, as well as the fact that changes at the transcriptome level of the processes of transport and mitochondrial biogenesis can play an important role in neurodegeneration in PD at an early stage.


Author(s):  
Shoaib Amin Banday ◽  
Mohammad Khalid Pandit

Introduction: Brain tumor is among the major causes of morbidity and mortality rates worldwide. According to National Brain Tumor Foundation (NBTS), the death rate has nearly increased by as much as 300% over last couple of decades. Tumors can be categorized as benign (non-cancerous) and malignant (cancerous). The type of the brain tumor significantly depends on various factors like the site of its occurrence, its shape, the age of the subject etc. On the other hand, Computer Aided Detection (CAD) has been improving significantly in recent times. The concept, design and implementation of these systems ascend from fairly simple ones to computationally intense ones. For efficient and effective diagnosis and treatment plans in brain tumor studies, it is imperative that an abnormality is detected at an early stage as it provides a little more time for medical professionals to respond. The early detection of diseases has predominantly been possible because of medical imaging techniques developed from past many decades like CT, MRI, PET, SPECT, FMRI etc. The detection of brain tumors however, has always been a challenging task because of the complex structure of the brain, diverse tumor sizes and locations in the brain. Method: This paper proposes an algorithm that can detect the brain tumors in the presence of the Radio-Frequency (RF) inhomoginiety. The algorithm utilizes the Mid Sagittal Plane as a landmark point across which the asymmetry between the two brain hemispheres is estimated using various intensity and texture based parameters. Result: The results show the efficacy of the proposed method for the detection of the brain tumors with an acceptable detection rate. Conclusion: In this paper, we have calculated three textural features from the two hemispheres of the brain viz: Contrast (CON), Entropy (ENT) and Homogeneity (HOM) and three parameters viz: Root Mean Square Error (RMSE), Correlation Co-efficient (CC), and Integral of Absolute Difference (IAD) from the intensity distribution profiles of the two brain hemispheres to predict any presence of the pathology. First a Mid Sagittal Plane (MSP) is obtained on the Magnetic Resonance Images that virtually divides brain into two bilaterally symmetric hemispheres. The block wise texture asymmetry is estimated for these hemispheres using the above 6 parameters.


Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 747
Author(s):  
Nicola Pusterla ◽  
Samantha Barnum ◽  
Julia Miller ◽  
Sarah Varnell ◽  
Barbara Dallap-Schaer ◽  
...  

Here we report on an EHV-1 outbreak investigation caused by a novel genotype H752 (histidine in amino acid position 752 of the ORF 30 gene). The outbreak involved 31 performance horses. Horses were monitored over a period of 35 days for clinical signs, therapeutic outcome and qPCR results of EHV-1 in blood and nasal secretions. The morbidity of the EHV-1 outbreak was 84% with 26 clinically infected horses displaying fever and less frequently anorexia and distal limb edema. Four horses showed mild transient neurological deficits. Clinically diseased horses experienced high viral load of EHV-1 in blood and/or nasal secretions via qPCR, while subclinically infected horses had detectable EHV-1 mainly in nasal secretions. The majority of infected horses showed a rise in antibody titers to EHV-1 during the outbreak. All 31 horses were treated with valacyclovir, while clinically infected horses further received flunixin meglumine and sodium heparin. This investigation highlights various relevant aspects of an EHV-1 outbreak caused by a new H752 genotype: (i) importance of early detection of EHV-1 infection; (ii) diagnostic challenge to assess H752 genotype; (iii) apparent benefit of valacyclovir use in the early stage of the outbreak; and (iv) weekly testing of blood and nasal secretions by qPCR in order to monitor individual infection status and lift quarantine.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Danielle M. Nash ◽  
Zohra Bhimani ◽  
Jennifer Rayner ◽  
Merrick Zwarenstein

Abstract Background Learning health systems have been gaining traction over the past decade. The purpose of this study was to understand the spread of learning health systems in primary care, including where they have been implemented, how they are operating, and potential challenges and solutions. Methods We completed a scoping review by systematically searching OVID Medline®, Embase®, IEEE Xplore®, and reviewing specific journals from 2007 to 2020. We also completed a Google search to identify gray literature. Results We reviewed 1924 articles through our database search and 51 articles from other sources, from which we identified 21 unique learning health systems based on 62 data sources. Only one of these learning health systems was implemented exclusively in a primary care setting, where all others were integrated health systems or networks that also included other care settings. Eighteen of the 21 were in the United States. Examples of how these learning health systems were being used included real-time clinical surveillance, quality improvement initiatives, pragmatic trials at the point of care, and decision support. Many challenges and potential solutions were identified regarding data, sustainability, promoting a learning culture, prioritization processes, involvement of community, and balancing quality improvement versus research. Conclusions We identified 21 learning health systems, which all appear at an early stage of development, and only one was primary care only. We summarized and provided examples of integrated health systems and data networks that can be considered early models in the growing global movement to advance learning health systems in primary care.


Actuators ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 87
Author(s):  
Nicholas A. Jones ◽  
Jason Clark

This paper presents a structural geometry for increasing piezoelectric deformation, which is suitable for both micro- and macro-scale applications. New and versatile microstructure geometries for actuators can improve device performance, and piezoelectric designs benefit from a high-frequency response, power density, and efficiency, making them a viable choice for a variety of applications. Previous works have presented piezoelectric structures capable of this amplification, but few are well-suited to planar manufacturing. In addition to this manufacturing difficulty, a large number of designs cannot be chained into longer elements, preventing them from operating at the macro-scale. By optimizing for both modern manufacturing techniques and composability, this structure excels as an option for a variety of macro- and micro-applications. This paper presents an analytical compact model of a novel dual-bimorph piezoelectric structure, and shows that this compact model is within 2% of a computer-distributed element model. Furthermore it compares the actuator’s theoretical performance to that of a modern actuator, showing that this actuator trades mechanical efficiency for compactness and weight savings.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 892
Author(s):  
Elisa L. J. Moya ◽  
Elodie Vandenhaute ◽  
Eleonora Rizzi ◽  
Marie-Christine Boucau ◽  
Johan Hachani ◽  
...  

Central nervous system (CNS) diseases are one of the top causes of death worldwide. As there is a difficulty of drug penetration into the brain due to the blood–brain barrier (BBB), many CNS drugs treatments fail in clinical trials. Hence, there is a need to develop effective CNS drugs following strategies for delivery to the brain by better selecting them as early as possible during the drug discovery process. The use of in vitro BBB models has proved useful to evaluate the impact of drugs/compounds toxicity, BBB permeation rates and molecular transport mechanisms within the brain cells in academic research and early-stage drug discovery. However, these studies that require biological material (animal brain or human cells) are time-consuming and involve costly amounts of materials and plastic wastes due to the format of the models. Hence, to adapt to the high yields needed in early-stage drug discoveries for compound screenings, a patented well-established human in vitro BBB model was miniaturized and automated into a 96-well format. This replicate met all the BBB model reliability criteria to get predictive results, allowing a significant reduction in biological materials, waste and a higher screening capacity for being extensively used during early-stage drug discovery studies.


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