Nonlinear PDE control of flexible robotic arms for state tracking and link-deflection mitigation

This work presents a novel nonlinear control scheme for simultaneous state tracking and mitigation of undesired deflection effects in flexible robotic manipulators. The presented method directly incorporates the partial differential equations (PDEs) used for describing dynamics of the mechanism into the corresponding control calculations and assumes no form of reduction in PDEs (which in this work have been derived according to extended Hamilton principle for a rigid-flexible manipular when considering the flexible arm as an Euler-Bernoulli beam). Hence, the presented methodology should be considered as considerably more feasible for a wide range of applications in comparison with the conventional strategies which use assumed modes to analyze link flexibility dynamics or vibration effects. Furthermore, the proposed controller ensures state tracking and link-deflection boundedness only using standard control inputs to the mechanism without incorporating additional boundary inputs (which essentially represents satisfaction of more control objectives than the limited number of inputs would allow in conventional controllers), which would render it a viable choice for robotic applications where additional inputs cannot be easily exerted to end effector or cases where this strategy would require significant modifications in existing devices. Numerical simulations indicate the effectiveness of the presented control scheme.acceptedVersionPeer reviewe

Эффективность in vitro инактивации бактерий Bacillus subtilis и Escherichia coli в стерилизаторах с использованием облучения в фиолетовой области

Bacteria are inactivated using a technique called photodynamic inactivation, which combines light with a photosensitizer with the right spectrum. The objective of this study is to ascertain the e­ciency of purple LEDs for photoinactivating Bacillus subtilis and Escherichia coli bacteria as well as the ideal purple LED exposure energy density. This study technique involves exposing bacteria to purple LED radiation. Two elements of variation are used during irradiation. The first variation is the illumination variation at distances of 3 cm, 6 cm, 9 cm, and 12 cm. The second variation involves changing the amount of radiation for 30, 60, 90, and 120 minutes. The Total Plate Count (TPC) method was used to count the number of colonies. Statistical tests were utilized in data analysis, namely the One Way Anova test (analysis of variance). The results of this study indicated that 395 nm purple LED irradiation caused a decrease in Log CFU/mL of Bacillus subtilis and Escherichia coli bacteria. Inactivation of Bacillus subtilis bacteria showed a higher mortality percentage than Escherichia coli bacteria. Changes in other irradiation distances also showed a higher percentage of death for Bacillus subtilis bacteria than Escherichia coli bacteria. The highest percentage of death was 98.5% for Bacillus subtilis bacteria and 94.3% for Escherichia coli bacteria at position C with an irradiation distance of 3 cm and an energy density of 524 J/cm2 with an LED exposure time of 120 minutes. This shows that the percentage of death of bacteria Bacillus subtilis and Escherichia coli increased with increasing doses of LED energy with the greatest percentage of death in Gram-positive bacteria Bacillus subtilis.Инактивация бактерий может быть выполнена с использованием метода, называемого фотодинамической инактивацией, в основе которого лежит активация фотосенсибилизатора светом определенного спектра. Целью данного исследования является определение эффективности светодиодов с излучением в фиолетовой области спектра для фотоинактивации бактерий Bacillus subtilis и Escherichia coli, а также определение оптимальной плотности энергии воздействия. При облучении были использованы два изменяемых параметра. Первый параметр – это расстояние от источника облучения до облучаемой поверхности (3 см, 6 см, 9 см и 12 см). Второй параметр – время облучения (30, 60, 90 и 120 мин). Для подсчета количества колоний использовали метод общего подсчета чашек (Total Plate Count). При анализе данных использовали статистические тесты, а именно тест One Way Anova (дисперсионный анализ). Результаты этого исследования показали, что светодиодное излучение в фиолетовой области спектра с длиной волны 395 нм вызывало снижение log КОЕ/мл бактерий Bacillus subtilis и Escherichia coli. Воздействие на бактерии Bacillus subtilis показало более высокий процент смертности, чем для бактерий Escherichia coli. Лучшие результаты были получены при расстоянии до источника облучения 3 см, плотности энергии 524 Дж/см2, и времени воздействия светодиода 120 мин. В этом режиме было инактивировано 98,5% бактерий Bacillus subtilis и 94,3% бактерий Escherichia coli

Антибактериальная эффективность хлорофилла листьев катука (Sauropus androgynus (L) Merr) с активацией синим и красным лазером в отношении биопленки aggregatibacter actinomycetemcomitans и enterococcus faecalis

In this study, the efficacy of using Sauropus androgynus (L) Merr, a katuk leaf chlorophyll photosensitizer, to reduce Aggregatibacter actinomycetemcomitans and Enterococcus faecalis biofilm was investigated. A red and blue diode laser is used as the light source. The sample was split into four groups: a negative control group, a positive control group, a blue laser treatment group (B), and a red laser treatment group (R), both with and without the addition of katuk leaf chlorophyll 1.6 mg/ml, and with varying densities of laser energy exposure of 2.5 J/cm2, 5 J/cm2, 7.5 J/cm2, and 10 J/cm2. Laser exposure and chlorophyll photosensitizer were tested using ELISA and ANOVA. At an energy density of 10 J/cm2, the optimal bacterial mortality rate was obtained in each treatment group. Namely, in the Aggregatibacter actinomycetemcomitans biofilm, the negative group, the number of deaths was 73.30% using a blue diode laser and 63.25% using a red diode laser. In the positive group, the number of deaths was 86.12% using a blue diode laser and 83.29% using a red diode laser. In the Enterococcus faecalis biofilm, in the negative group, the number of deaths was 67.78% using the blue diode laser and 75.33% using the red diode laser, and in the positive group, the number of deaths was 71.71% using the blue diode laser and 86.41 using a red diode laser. Exposure to blue and red diode lasers activates chlorophyll in katuk leaves, killing bacteria and reducing biofilms.Изучена фотодинамическая активность фотосенсибилизатора хлорофилла листьев катука в отношении биопленки Aggregatibacter actinomycetemcomitans и Enterococcus faecalis. В качестве источника света был использован красный и синий диодный лазер. В исследование были четыре группы: группа отрицательного контроля, группа положительного контроля, группа обработки синим лазером (B) и группа обработки красным лазером (R), как с добавлением, так и без добавления хлорофилла листьев катука в концентрации 1,6 мг/мл, а также при различной плотности энергии лазерного излучения: 2,5 Дж/см2, 5 Дж/см2, 7,5 Дж/см2 и 10 Дж/см2. Эффективность воздействия оценивали с помощью ELISA и ANOVA. Наибольшая эффективность была зарегистрирована во всех режимах воздействия (красный/синий лазер, без/с хлорофиллом) при плотности энергии 10 Дж/см2. В биопленке Aggregatibacter actinomycetemcomitans в контрольных группах (только облучение) эффективность составила 73,30% при использовании синего диодного лазера и 63,25% при использовании красного диодного лазера, а в опытных группах эффективность составила 86,12% при использовании синего диодного лазера и 83,29% при использовании красного диодного лазера. В биопленке Enterococcus faecalis в контрольных группах эффективность составила 67,78% при использовании синего диодного лазера и 75,33% при использовании красного диодного лазера, а в опытных группах эффективность составила 71,71% при использовании синего диодного лазера и 86,41% с использованием красного диодного лазера. Таким образом, сделан вывод, что воздействие синего и красного диодных лазеров активирует хлорофилл в листьях катука, обладая бактерицидным действием бактерии и уменьшая биопленки

Selected pomegranate germplasm from Afghanistan: morphological variability and relationship among collected accessions

During the period 2008-09 and in the frame of PHDP 58 Afghan and 18 foreign pomegranate accessions have been collected and grown under homogeneous environmental and cultivation practice conditions in ex situ collections. Standardized procedures were adopted to describe mature trees, leaves, flowers and fruits for a total of 30 phenotypic traits. Within the National Collection of Pomegranate of Afghanistan, coefficients of variability ranged from 8.8 to 31.7% for fruit diameter and weight of non edible part, respectively. Principal component analysis revealed the absence of correlated variables among different organs. The whole set of accessions resulted discriminated on the basis of the studied morphological parameters and all the accessions were grouped into 3 sub-sets by hierarchical cluster analysis. Local accessions resulted distributed in the 3 clusters, nevertheless the largest one held all the foreign varieties while the second one included all the accessions collected under the putative name of ‘Bedana’. The adopted morphological studies allowed to identify one true-to-type ‘Bedana’ accession, considered the best Afghan variety for fresh consume due to its very soft seed, and to solve the cases of homonymy. Analogously, various accessions originally collected from different regions of Afghanistan under the name of ‘Kandahari’ were identified and renamed

A review of friction models in interacting joints for durability design.

This paper presents a comprehensive review of friction modelling to provide an understanding of design for durability within interacting systems. Friction is a complex phenomenon and occurs at the interface of two components in relative motion. Over the last several decades, the effects of friction and its modelling techniques have been of significant interests in terms of industrial applications. There is however a need to develop a unified mathematical model for friction to inform design for durability within the context of varying operational conditions. Classical dynamic mechanisms model for the design of control systems has not incorporated friction phenomena due to non-linearity behaviour. Therefore, the tribological performance concurrently with the joint dynamics of a manipulator joint applied in hazardous environments needs to be fully analysed. Previously the dynamics and impact models used in mechanical joints with clearance have also been examined. The inclusion of reliability and durability during the design phase is very important for manipulators which are deployed in harsh environmental and operational conditions. The revolute joint is susceptible to failures such as in heavy manipulators these revolute joints can be represented by lubricated conformal sliding surfaces. The presence of pollutants such as debris and corrosive constituents has the potential to alter the contacting surfaces, would in turn affect the performance of revolute joints, and puts both reliability and durability of the systems at greater risks of failure. Key literature is identified and a review on the latest developments of the science of friction modelling is presented here. This review is based on a large volume of knowledge. Gaps in the relevant field have been identified to capitalise on for future developments. Therefore, this review will bring significant benefits to researchers, academics and industrial professionals

Epigenetic dysregulation of HTR2A in the brain of patients with schizophrenia and bipolar disorder

Introduction: HTR2A gene has been the subject of numerous studies in psychiatric genetics because LSD, which resembles serotonin causes psychosis and atypical antipsychotic drugs target the HTR2A receptor. However, evidence for the role of HTR2A polymorphism(s) in schizophrenia (SCZ) and bipolar disorder (BD) has been elusive. We hypothesized that epigenetic dysregulation of HTR2A may be involved in psycho-pathogenesis and analyzed promoter DNA methylome and expression of HTR2A in SCZ, BD and control subjects. Method: DNA derived from post-mortem brains of patients with SCZ and BD and matched control subjects (each 35) were obtained from the Stanley Medical Research Institute. While bisulfite DNA sequencing was used to screen and quantify cytosine methylation in the HTR2A promoter, corresponding gene expression was analyzed by qRT-PCR. Results: We found strong evidence for epigenetic fine-tuning of HTR2A expression. In general, the expression of HTR2A in individuals carrying the C allele of T102C (or G allele of -1438A/G polymorphism) was higher than TT genotype. Interestingly, promoter DNA of HTR2A was hypermethylated at and around the -1438A/G polymorphic site, but was hypomethylated at and around T102C polymorphic site in SCZ and BD compared to the controls. Furthermore, epigenetic down-regulation of HTR2A was associated with early age of disease onset in SCZ and BD. Conclusion: Epigenetic dysregulation of HTR2A may contribute to SCZ, BD and earlier age of disease onset. Further research is required to delineate the dysregulation of other components of serotoninergic pathway to design new therapeutics based on the downstream effects of serotonin. © 2011 Elsevier B.V

Ameliorative and Renoprotective Effect of Electrical Stimulation on Blood Sugar, Blood Urea Nitrogen (BUN), Creatinine Levels, and the Islets of Langerhans Weight in Diabetic Mice

Diabetes mellitus (DM) is a chronic metabolic disease or disorder characterized by high blood sugar levels as well as impaired carbohydrate, lipid, and protein metabolism due to insulin function insufficiency. Insulin deficiency can be caused by impaired or deficient insulin production by Langerhans beta cells in the pancreas or by a lack of responsiveness of the body's cells to insulin. This study aims to the effects of electrostimulation on the ameliorative (improves disease manifestations) or renoprotective (protects the kidneys) in a diabetic rat model using noninvasive (electrical stimulation with the magnetic and nonmagnetic electrode) and invasive (using needles) methods. This study used 25 female rats, with a normal control group (KN), a diabetes control group (KD), a needle treatment group (A), an electro-stimulator treatment group with a magnetic electrode (M), and an ES group with a nonmagnetic electrode (ES) (L). The electro-stimulator used AES-05 with a magnetic field strength of 90 mT at two acupoints, Pishu (BL20) and Shenshu (BL23). The treatment was administered 12 times in one month with a therapy time of 6.6 minutes per session. Body weight and blood sugar levels were compared before and after the treatment. After treatment, the diameter of the islets of Langerhans, as well as levels of creatinine and blood urea nitrogen (BUN), was measured. Furthermore, statistical analysis was performed (α = 0.05). The results of this study showed that electrical stimulation treatments with needle-invasive, noninvasive magnetic electrodes, and nonmagnetic electrodes significantly reduced diabetic rats’ blood glucose levels before and after the treatment. The analysis of the diameter of the islets of Langerhans revealed a significant difference between the treatment groups. The analysis of creatinine levels revealed a significant difference between groups, but creatinine levels in the group with the magnetic electrode (0.58 ± 0.17 mg/dL) were not significantly different from the control group (0.58 ± 0.07 mg/dL). The BUN test results revealed a significant difference compared with the diabetic control group, but no significant difference with the magnetic electrode treatment group. Conclusion. Based on the results, the most effective therapy for diabetes is a noninvasive method with magnetic (M) electrodes