Different Layers Of Tissue Research Articles

Elastic behaviour of bamboo at nano- and microscale

This paper presents an anatomy-based numerical multiscale approach for modelling the mechanical behaviour of Moso bamboo, addressing limitations in previous research where the intricate microstructure was often simplified. The mechanical response of bamboo culms is predicted at the nano and microscale considering the orthotropic behaviour of cellulose microfibrils in different layers of tissues, deviating from conventional isotropic assumptions. Through nano and microscale finite element models, the impact of chemical composition and microfibril angle on elastic properties of different layers of the fibre and parenchyma cells are explored at two different levels of moisture content. At low moisture content, fibres within vascular bundles exhibit significantly higher longitudinal and transverse elastic moduli compared to parenchyma cells. When the moisture content is high, the properties of the fibre and parenchyma cells are less different. Anisotropic behaviour at the nanoscale contributes to a more accurate prediction of the mechanical properties of bamboo culms at the microscale, particularly in the transverse direction in moist conditions. This study lays the groundwork for forthcoming research in modelling the mechanical behaviour of bamboo culm at meso and macroscales.

Early detection of gastric cancer via high-resolution terahertz imaging system.

Terahertz (THz) wave has demonstrated a good prospect in recent years, but the resolution is still one of the problems that restrict the application of THz technology in medical imaging. Paraffin-embedded samples are mostly used in THz medical imaging studies, which are thicker and significantly different from the current gold standard slice pathological examination in sample preparation. In addition, THz absorption in different layers of normal and cancerous tissues also remains to be further explored. In this study, we constructed a high-resolution THz imaging system to scan non-tumorous adjacent tissue slices and gastric cancer (GC) tissue slices. In this system, a THz quantum cascade laser emitted a pulsed 3THz signal and the transmitted THz wave was received by a THz detector implemented in a 65nm CMOS process. The slice thickness was only 20μm, which was close to that of the medical pathology examination. We successfully found THz transmittance differences between different layers of normal gastric tissues based on THz images, and the resolution could reach 60μm for the first time. The results indicated that submucosa had a lower THz transmittance than that of mucosa and muscular layer in non-tumorous adjacent tissue. However, in GC tissue, THz transmittance of mucosa and submucosa was similar, caused by the decreased transmittance of mucosa, where the cancer occurs. Therefore, we suppose that the similar terahertz transmittance between gastric mucosa and submucosa may indicate the appearance of cancerization. The images obtained from our THz imaging system were clearer than those observed with naked eyes, and can be directly compared with microscopic images. This is the first application of THz imaging technology to identify non-tumorous adjacent tissue and GC tissue based on the difference in THz wave absorption between different layers in the tissue. Our present work not only demonstrated the potential of THz imaging to promote early diagnosis of GC, but also suggested a new direction for the identification of normal and cancerous tissues by analyzing differences in THz transmittance between different layers of tissue.

BEHAVIOR OF THE SQUARE WAVE IN BIOLOGICAL STRUCTURES

This study is to experimentally investigate the behavior of quadratic waves in biological structures. Transcutaneous frequency stimulation was regulated so that the system provided high frequency and low electrical voltage to observe possible changes in deeper layers of the anatomical structure analyzed. Electrodes were positioned from the dermis and probing electrodes were positioned at the subdermal, intradermal, skeletal muscle, periosteum, endosteum, and medulla levels. A function generator connected to a digital oscilloscope produced a square wave of 33 kHz at 10µs pulse speed and voltage of 16 volts DC. A voltage decay was observed as the signal reached deeper layers of different tissues. However, the frequency of 33 kHz remained uniform even at the bone marrow level. This observation opens the way for the application of the square electronic frequency as a stimulus for drug activation.

Enhanced Vascular Features in Porcine Gastrointestinal Endoscopy Using Multispectral Imaging.

Endoscopic investigation is a predominant stan-dard while assessing the gastrointestinal tract. Even though it has been rigorously used in diagnostics for many decades, a high miss rate has been recorded. Advanced endoscopic imaging still has not found solutions to problems like early cancer detection, polyp generality, disease classification, etc. One of the less explored techniques to study early cancer detection is spectral imaging which deals with the absorption and reflection spectra of various wavelengths of light by different layers of tissue. To study tissues under various illumination, a multi-spectral light source unit that can be used along with an endoscopy system was developed with 10 different LEDs of very narrow bandwidths. Using this light source, a feasibility study was per-formed on an animal in which the upper GI tract of a porcine model was imaged and sample images were taken for processing from five different sections. Some wavelengths showed better contrast enhancements for visualization of vascular structures. Wavelength 420 nm (violet light) showed better contrast and the gradient of the line profile histogram showed the highest intensity change between the blood vessels and the surrounding mucosa. These enhancements showed that spectral imaging can potentially help in studying tissues for early cancer detection and improved visualization of the G I tract using endoscopy.

Electroacupuncture and Moxibustion-Like Stimulation Relieves Inflammatory Muscle Pain by Activating Local Distinct Layer Somatosensory Afferent Fibers

Recent studies have shown that both superficial and deep acupuncture produced clinically relevant and persistent effect on chronic pain, and several subtypes of somatic primary afferents played critical roles in acupuncture and moxibustion analgesia. However, which kind of primary afferents in the superficial and deep tissue of the acupoint is activated by acupuncture or moxibustion to relieve pain persistently remains unclear. The aim of this study is to investigate the roles of distinct peripheral afferents in different layers of the tissue (muscle or skin) in the acupoint for pain relief. Muscular A-fibers activated by deep electroacupuncture (dEA) with lower intensity (approximately 1 mA) persistently alleviated inflammatory muscle pain. Meanwhile, cutaneous C-nociceptors excited by noxious moxibustion-like stimulation (MS) and topical application of capsaicin (CAP) on local acupoint area produced durable analgesic effect. Additionally, spontaneous activity of C-fibers caused by muscular inflammation was also inhibited by dEA and CAP. Furthermore, decreases in pain behavior induced by dEA disappeared after deep A-fibers were demyelinated by cobra venom, whereas CAP failed to relieve pain following cutaneous denervation. Collectively, these results indicate that dEA and MS ameliorate inflammatory muscle pain through distinct primary afferents in different layers of somatic tissue; the former is achieved by activating muscular A-fibers, while the latter is mediated by activating cutaneous C-fibers.

A novel optical technology based on 690\xa0nm and 850\xa0nm wavelengths to assist needle thoracostomy

The sensitivity of pneumothorax diagnosis via handheld ultrasound is low, and there is no equipment suitable for use with life-threatening tension pneumothorax in a prehospital setting. This study proposes a novel technology involving optical fibers and near-infrared spectroscopy to assist in needle thoracostomy decompression. The proposed system via the optical fibers emitted dual wavelengths of 690 and 850 nm, allowing distinction among different layers of tissue in vivo. The fundamental principle is the modified Beer–Lambert law (MBLL) which is the basis of near-infrared tissue spectroscopy. Changes in optical density corresponding to different wavelengths (690 and 850 nm) and hemoglobin parameters (levels of Hb and HbO2) were examined. The Kruskal–Wallis H test was used to compare the differences in parameter estimates among tissue layers; all p-values were < 0.001 relevant to 690 nm and 850 nm. In comparisons of Hb and HbO2 levels relative to those observed in the vein and artery, all p-values were also < 0.001. This study proposes a new optical probe to assist needle thoracostomy in a swine model. Different types of tissue can be identified by changes in optical density and hemoglobin parameters. The aid of the proposed system may yield fewer complications and a higher success rate in needle thoracostomy procedures.

A Computational Study of 2.4 and 3.7 GHz Radiations Deposition Inside Models Made of Human Tissues Placed Nearby a Microstrip Antenna

Abstract The interest for GHz frequency range in present wireless communication devices is high. Therefore, a continuous need to observe peculiarities of electromagnetic power deposition in human tissues, when they are exposed to signals in this range, is obvious. In this paper, by using an electromagnetic field simulation software, we aimed to highlight the differences between specific absorption rates (SAR) of energy absorption and their geometric distribution in four cases: at two different frequencies and in two tissue models (plane and anthropomorphic). First step was to design and analyse the electromagnetic field provided by a microstrip antenna, and second step was to compute SAR averaged over 10 g of tissue in two models: a three-layered planar model of human tissues and a homogeneous human head. Similarities and differences are discussed, together with observations regarding temperature increase due to exposures and its trend in different layers of tissues.

Surface Density of the Spongy and Palisade Parenchyma Layers of Leaves Extracted From Wideband Ultrasonic Resonance Spectra.

The wide band and air-coupled ultrasonic resonant spectroscopy together with a modified Simulated Annealing metaheuristic algorithm and a 1D layered acoustic-model are used to resolve the structure of plant leaves. In particular, this paper focuses on the extraction of the surface density of the different layers of tissue in leaves having a relatively simple structure. There are three main reasons to select the surface density as the focus of this study: (i) it is a parameter directly extracted by the proposed technique and it requires no further processing, (ii) it is relevant in order to study the dynamic of the water within the different tissues of the leaves and also to study the differential development of the different tissues, and (iii) unlike other parameters provided by this technique (like resonant frequency, impedance, ultrasonic elastic modulus, or ultrasonic damping), this parameter can be easier to understand as it is a direct measure of mass per unit surface. The selection of leaves with a simple structure is justified by the convenience of avoiding an unnecessary complication of the data extraction step. In this work, the technique was applied to determine the surface density of the palisade and spongy parenchyma layers of tissue of Ligustrum lucidum, Vitis vinifera, and Viburnum tinus leaves. The first species was used to study the variation of the surface density at full turgor with the thickness of the leaf, while the two other species were used to study the variation of the surface densities with the variation in the leaf relative water content. Consistency of the results with other conventional measurements (like overall surface density, and cross-section optical and cryo-SEM images) is discussed. The results obtained reveal the potential of this technique; moreover, the technique presents the additional advantage that can be applied in-vivo as it is completely non-invasive, non-destructive, fast, and equipment required is portable.

Polarization gating technique extracts depth resolved fluorescence redox ratio in oral cancer diagnostics.

Mortality of oral cancer is often due to late diagnosis. Effective non-invasive diagnostic techniques may increase the survival rate based on an earlier diagnosis.. We report on the application of the polarization gating technique for isolating weakly scattered and highly scattered components of fluorescence emission from the superficial and deeper layers of tissue due to intrinsic fluorophores NADH and FAD. The fluorescence polarization spectra were collected from 21 normal and 67 oral squamous cell carcinoma biopsy tissues. The tissues were excited at 350 nm and the fluorescence emission had two peaks corresponding to NADH, and FAD respectively. The spectra were analyzed using the polarization gating technique along with the spectral deconvolution method to derive the optical redox ratio from different layers of tissue. The fractional change in redox ratio between superficial and deeper layers of tissue exhibits excellent statistical significance (p<10-3) which may be due to a shift in the metabolic pathway from oxidative phosphorylation to glycolysis in the cancer cell. Further, variation in collagen intensity in deeper layers of tissue is observed which may be attributed to the breakdown of collagen fibers in the stroma. Linear discriminant analysis showed that oral cancer tissue is discriminated with a better accuracy using polarization gating technique than that of conventional fluorescence spectroscopy.

Precise application of Traditional Chinese Medicine in minimally-invasive techniques

Precise application of Traditional Chinese Medicine in minimally-invasive techniques

Overview and Comparison of Intestinal Organotypic Models, Intestinal Cells, and Intestinal Explants Used for Toxicity Studies.

The intestine is a complex organ formed of different types of cell distributed in different layers of tissue. To minimize animal experiments, for decades, researchers have been trying to develop in vitro/ex vivo systems able to mimic the cellular diversity naturally found in the gut. Such models not only help our understanding of the gut physiology but also of intestinal toxicity. This review describes the different systems used to evaluate the effects of drugs/contaminants on intestinal functions and compares their advantages and limitations. The comparison showed that the organotypic model is the best available model to perform intestinal toxicity studies, including on human tissues.

Virtual three-dimension reconstruction of Sìdú ( TE 9) (TE 9)

ObjectiveAim to create a three-dimension (3D) reconstruction of acupuncture needling at Sìdú (▪ TE 9). MethodsFirst, the skin, subcutaneous tissue, muscles, the blood vessels and nerves near TE 9 were defined in anatomical terms. Second, the above anatomical structures including the dissected muscles associated with at TE 9, the underlying blood vessels and nerves were reconstructed in 3D. Third, the process of acupuncturing TE 9 on a virtual human body was simulated using the VOXEL-MAN technology. ResultsBoth the local anatomy of the point and the process of acupuncture needling at TE 9 were reconstructed. Different layers of tissues were visualized during the process of needling, as the needle was inserted and manipulated at the point. ConclusionsVirtual 3D reconstruction can contribute to research on the anatomical structure of acupoints and the visualization of the acupoints. We recommend that it be fully utilized in acupuncture research.

Negative-pressure wound therapy enhances local inflammatory responses in acute infected soft-tissue wound.

Clinical studies found that negative-pressure wound therapy (NPWT) displayed significant clinical benefits in the healing of infected wounds. However, the effect of NPWT on local inflammatory responses in acute infected soft-tissue wound has not been investigated thoroughly. The purpose of this study was to test the impact of NPWT on local expression of proinflammatory cytokines, amount of neutrophils, and bacterial bioburden in wound from acute infected soft-tissue wounds. Full-thickness wounds were created on the back of rabbits, and were inoculated with Staphylococcus aureus strain ATCC29213. The wounds were treated with sterile saline-moistened gauze dressings and NPWT with continuous negative pressure (-125 mmHg). Wound samples were harvested on days 0 (6 h after bacterial inoculation), 2, 4, 6, and 8 at the center of wound beds before irrigation for real-time PCR analysis of gene expression of IL-1β, IL-8, and TNF-α. Wound biopsies were examined histologically for neutrophil quantification in different layers of tissue. Quantitative bacterial cultures at the same time point were analyzed for bacterial clearance. Application of NPWT to acute infected wounds in rabbits was compared with treatment with sterile saline-moistened gauze, over an 8-day period. NPWT-treated wounds exhibited earlier and greater peaking of IL-1β and IL-8 expression and decrease in TNF-α expression over the early 4 days (P < 0.05). Furthermore, histologic examination revealed that significantly increased neutrophil count was observed in the shallow layer in wound biopsies of NPWT treatment at day 2 (P < 0.001). In addition, there was a statistically significant decrease of bacteria load from baseline (day 0) at days 2 and 8 in NPWT group (P < 0.05). In conclusion, this study demonstrates that NPWT of acute infected soft-tissue wounds leads to increased local IL-1β and IL-8 expression in early phase of inflammation, which may trigger accumulation of neutrophils and thus accelerate bacterial clearance. Meanwhile, the success of NPWT in the treatment of acute wounds can attenuate the expression of TNF-α, and the result may partly explain how NPWT can avoid significantly impairing wound healing.

Three-Dimensional Scaffolds for Tissue Engineering Applications: Role of Porosity and Pore Size

Tissue engineering applications commonly encompass the use of three-dimensional (3D) scaffolds to provide a suitable microenvironment for the incorporation of cells or growth factors to regenerate damaged tissues or organs. These scaffolds serve to mimic the actual in vivo microenvironment where cells interact and behave according to the mechanical cues obtained from the surrounding 3D environment. Hence, the material properties of the scaffolds are vital in determining cellular response and fate. These 3D scaffolds are generally highly porous with interconnected pore networks to facilitate nutrient and oxygen diffusion and waste removal. This review focuses on the various fabrication techniques (e.g., conventional and rapid prototyping methods) that have been employed to fabricate 3D scaffolds of different pore sizes and porosity. The different pore size and porosity measurement methods will also be discussed. Scaffolds with graded porosity have also been studied for their ability to better represent the actual in vivo situation where cells are exposed to layers of different tissues with varying properties. In addition, the ability of pore size and porosity of scaffolds to direct cellular responses and alter the mechanical properties of scaffolds will be reviewed, followed by a look at nature's own scaffold, the extracellular matrix. Overall, the limitations of current scaffold fabrication approaches for tissue engineering applications and some novel and promising alternatives will be highlighted.

Separation of Integument and Nucellar Tissues from Cotton Ovules ( Gossypium hirsutum L.) for both High- and Low-Throughput Molecular Applications

Here we present a quick and low-cost method to separate the different layers of tissue from the ovules and young seeds of cotton (Gossypium hirsutum L.) for use in high- and low-throughput molecular applications. This method is performed at room temperature using standard laboratory equipment and does not require embedding of the samples, time-consuming fixation, or micro-sectioning procedures. We show that the three main tissues can be efficiently separated from isolated ovules collected on the day of anthesis. RNA and genomic DNA extracted from tissues separated by this method are of good quality and suitable for a variety of molecular applications to study the early stages of cotton seed and fiber development.

Scrotal cancer survival is influenced by histology: a SEER study

Due to the scrotum's multiple layers of different tissues, scrotal cancer can present with several unique histologies. Historically, outcome arising from these different sources has been historically aggregated together. However, it remains unclear whether survival differs by histology of scrotal cancer. We queried the seventeen registries of the Surveillance, Epidemiology, and End Results database for patients diagnosed with primary scrotal cancer from 1973 to 2006. Patients were initially grouped by the following histologies: basal cell carcinoma, Extramammary Paget's Disease (EMPD), sarcoma, melanoma, squamous cell carcinoma, and adnexal skin tumors. For some analyses, the former three histologies were reclassified as Low-Risk scrotal cancer and the latter three histologies as High-Risk scrotal cancer. Kaplan-Meier survival analyses were conducted to assess the impact of histology on overall survival (OS). The cohort consisted of 766 patients. Median (95% CI) OSs by histologies were basal cell carcinoma--143 (116-180), EMPD--165 (139-190), sarcoma--180 (141-219), melanoma--136 (70-203), squamous cell carcinoma--115 (97-133), and adnexal skin tumors--114 (55-174). Patients with Low-Risk scrotal cancer experienced a median (95% CI) OS of 166 (145-188) months, while patients with High-Risk scrotal cancer experienced a median (95% CI) OS of 118 (101-135) months. Survival of scrotal cancer depends on tumor histology. Classification of histologies into Low and High Risk can be clinically useful for counseling and clinical decisions.

Use of Ultrasound to Provide Overall Information on Facial Fillers and Surrounding Tissue

Information on fillers and their behavior over time in the different layers of tissue is limited. Ultrasound may be used to visualize these fillers and their surrounding tissue to broaden knowledge. To evaluate the use of ultrasound as a diagnostic and research tool to obtain information on facial fillers and their behavior in human tissue. Patients with a history of facial filler treatment were examined using ultrasound in an outpatient setting. Seventy-two patients were examined. Hydrophilic fillers were echo visible, whereas tissue-generating fillers, permanent and resorbable, could be detected according to their tissue-generating reaction within the tissue. Filler characteristics such as longevity and reaction within the tissue and complications such as migration and granulomas could be visualized. The use of ultrasound may provide information to broaden our knowledge of facial fillers and may improve the performance and safety of filler treatments. The authors have indicated no significant interest with commercial supporters.

Expression of components of Wnt and Hedgehog pathways in different tissue layers during lung development in Xenopus laevis

Although Wnt and Hedgehog (Hh) signaling pathways play important roles in mouse lung development, these have not been explored in the development of Xenopus lung. This may be due to the lack of specific molecular markers for different layers of tissue in Xenopus lung and/or insufficient knowledge on expression patterns of Wnt and Hh signaling components in Xenopus lung. In this study, we first described the early morphogenesis of Xenopus laevis lung by using surfactant protein C ( sftpc) as a marker of lung epithelium and compared it with the expression patterns of several genes of Wnt and Hh pathways in Xenopus lungs. Our data showed that wnt7b was expressed in the entire lung epithelium from stage 37 to stage 45, while two other Wnt signaling components, wnt5a and wif1 ( wnt inhibitory factor 1), were expressed in the mesenchyme layer of the entire lungs through stages 39–41. We also found that sonic hedgehog ( shh) was expressed at stage 41 only in the anterior, but not in the posterior part of the lungs. These results show the expression of wnt5a, wnt7b, wif1 and shh in different layers of tissue of Xenopus lungs at early developmental stages, which implies different roles of these genes in the early development of Xenopus lungs. Our study for the first time defined specific molecular markers for description of early lung development in Xenopus, as well as provided information about expression of components of Wnt and Hh pathways in early Xenopus lungs, which should be useful for future functional studies.

Organotypic Raft Cultures as an Effective In Vitro Tool for Understanding Raman Spectral Analysis of Tissue¶

There is a growing body of evidence showing that optical spectroscopy has the potential to be a useful in vivo diagnostic tool. Yet, so far there is no definitive cellular and biochemical understanding for the differences seen in the spectra from different tissue categories and disease states. In this study, we examine the use of organotypic raft cultures as an in vitro model of in vivo tissue conditions in an attempt to overcome some of the limitations of previously used methods. Organotypic raft cultures resembling normal and dysplastic epithelial cervical tissue were constructed and grown at an air–liquid interface for 2 weeks. Raman spectra of normal as well as dysplastic raft cultures were measured and compared with in vivo spectra from the corresponding tissue type. Histologic comparisons ensured that the raft cultures had similar structure and morphology to the corresponding intact tissue types. Raman spectra were also acquired from different layers of tissue. Spectral comparisons show that the Raman spectra of the raft cultures are similar to the spectra acquired from the cervix in vivo for both normal and dysplastic tissues. These results show that organotypic raft cultures are an effective and useful tool for the cellular and biochemical analysis of tissue spectroscopy.

Geometrical effects in mechanical characterizing of microneedle for biomedical applications

This paper proposes the design and implementation of MEMS (Micro Electro Mechanical Systems)-based in-plane silicon microneedles with explanation of integrated functionality for sensing the resistive forces offered by human skin. The proposed design dimensions are calculated by using the constraints of minimal microneedle dimension, force withstanding capabilities, and their relationship. The paper also proposes the novel fabrication process to realize the microneedles, along with the integrated sensors for sensing skin resistive forces at various depths. The idea of this microneedle prototype is based on the requirements of strength, robustness, minimal insertion pain, and tissue damage in patients. The fundamental constraints set the length of our proposed MEMS-based in-plane microneedle to be 600 μm. The design gives the optimal dimensions of length, width, and thickness both of microneedle and the channel running through it, while considering the influence of various mechanical forces. In addition, the skin also offers an opposing force on the microneedle, which changes with depth of microneedle, angle of insertion, and different layers of tissue penetrated. Three piezoelectric sensors are fabricated on the microneedle to give reliable skin resistance measurement for different insertion depth. Performance analysis is made to validate the proposed design approach for different microneedle geometries and sizes.