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light sense [keywords]
- Responsive ionic liquid-polymer 2D photonic crystal gas sensors. [JOURNAL ARTICLE]
- Analyst 2014 Oct 23.
We developed novel air-stable 2D polymerized photonic crystal (2DPC) sensing materials for visual detection of gas phase analytes such as water and ammonia by utilizing a new ionic liquid, ethylguanidine perchlorate (EGP) as the mobile phase. Because of the negligible ionic liquid vapor pressure these 2DPC sensors are indefinitely air stable and, therefore, can be used to sense atmospheric analytes. 2D arrays of ∼640 nm polystyrene nanospheres were attached to the surface of crosslinked poly(hydroxyethyl methacrylate) (pHEMA)-based polymer networks dispersed in EGP. The wavelength of the bright 2D photonic crystal diffraction depends sensitively on the 2D array particle spacing. The volume phase transition response of the EGP-pHEMA system to water vapor or gaseous ammonia changes the 2DPC particle spacing, enabling the visual determination of the analyte concentration. Water absorbed by EGP increases the Flory-Huggins interaction parameter, which shrinks the polymer network and causes a blue shift in the diffracted light. Ammonia absorbed by the EGP deprotonates the pHEMA-co-acrylic acid carboxyl groups, swelling the polymer which red shifts the diffracted light.
- Post-infectious glomerulonephritis presenting as acute renal failure in a patient with Lyme disease. [Journal Article]
- J Renal Inj Prev 2014; 3(1):17-20.
We report a case of a patient with acute renal failure in Lyme disease-associated focal proliferative mesangial nephropathy. Lyme disease is a vector-borne disease caused by Borrelia burgdorferi, transmitted by the bite of an infected ixodes tick. Post-infectious glomerulonephritis (GN)secondary to Borrelia burgdorferi infection in man could be fatal, as it is in canine Lyme borreliosis.A 61-year old man with chronic ethanolic hepatitis was admitted to a provincial hospital, complaining of nausea, diarrhoea and loss of his sense of taste. A few days prior hospitalization, he had been bitten by a tick. He developed erythema gyratum repens in the right leg, thorax and face. Kidney function was altered despite normal urine flow: creatinine 5.04 mg/dl and BUN 126 mg/dl. Urinalysis showed light proteinuria and microscopic hematuria. IgG and IgM antibodies to Borrelia burgdorferi were detected by ELISA and Western blot confirmed the diagnosis. Renal biopsy showed mild mesangial proliferation and mesangial and paramesangial deposits on AFOG stain. A diagnosis of acute renal failure in Lyme disease-associated focal proliferative IgA nephropathy was made. Intravenous antibiotic medication was started (ceftriaxone 1 gram daily i.v.). The patient was later discharged, serum creatinine had decreased to 3.5 mg/dl with a BUN of 58 mg/dl, and a slight improvement was observed on follow-up.Borrelia burgdorferi is a possible cause of post-infectious GN in humans as it is in dogs. Difficulties in identifying Borrelia burgdorferi may also be one of the reasons for the paucity of reports on the association of this infection with glomerulonephritis in humans. Currently, various types of histological renal lesions have been reported.
- [Getting qi and arrival of qi]. [English Abstract, Journal Article]
- Zhongguo Zhen Jiu 2014 Aug; 34(8):828-30.
In order to clarify the inter-relationship between getting qi and arrival of qi, the relevant theory in the Inner Canon of Yellow Emperor is re-considered, and then the relationship of the two concepts by combining with some opinions from scholars is compared and analyzed. Getting qi is the signal of acupuncture at an acupoint; also it is a sign of arrival of qi at an acupoint; what's more, it is the premise for reinforcing or reducing manipulation. The sensation of arrival of qi comes from both doctors and patients, characterized with explicit symptoms including "tight and swift", "sunken, sticky and tight", "light, loose and slow", "warm at the acupoint" or "cold at the acupoint" as well as implicit symptom including "qi moving along the meridians"; also there is the condition of qi regulation that is characterized with "paced and harmony" stomach qi. The arrival of qi could be divided into "qi moving to the needles" and "qi traveling to the diseases". The "qi moving to the needles" has similar meaning to getting qi. The "qi traveling to the diseases" is reflected as "qi arrival with efficacy" and characterized as an immediate effect or a delayed effect. There are differences between the concepts of getting qi and arrival of qi. Getting qi focuses on the importance of the doctor during acupuncture processes (differentiate the nature of qi, guard qi, manipulate qi), which also suggests the clinical significance of implicit getting qi. "Arrival of qi" emphasizes "qi arrival with efficacy", and indicates that during treatment the differences of the exterior or interior and deficit or surplus should be distinguished. For external and shallow diseases involving myofascia-related diseases, miu needling and shallow needling can achieve an immediate treatment effect; for deep, internal and deficient diseases, reinforcing or reducing manipulation should be used to achieve stomach qi, which has delayed effects but can be used as an indicator. It is believed that pulse diagnosis shall not be neglected in clinical treatment of acupuncture.
- Exploring avian deep-brain photoreceptors and their role in activating the neuroendocrine regulation of gonadal development. [JOURNAL ARTICLE]
- Poult Sci 2014 Oct 20.
In the eyes of mammals, specialized photoreceptors called intrinsically photosensitive retinal ganglion cells (ipRGC) have been identified that sense photoperiodic or daylight exposure, providing them over time with seasonal information. Detectors of photoperiods are critical in vertebrates, particularly for timing the onset of reproduction each year. In birds, the eyes do not appear to monitor photoperiodic information; rather, neurons within at least 4 different brain structures have been proposed to function in this capacity. Specialized neurons, called deep brain photoreceptors (DBP), have been found in the septum and 3 hypothalamic areas. Within each of the 4 brain loci, one or more of 3 unique photopigments, including melanopsin, neuropsin, and vertebrate ancient opsin, have been identified. An experiment was designed to characterize electrophysiological responses of neurons proposed to be avian DBP following light stimulation. A second study used immature chicks raised under short-day photoperiods and transferred to long day lengths. Gene expression of photopigments was then determined in 3 septal-hypothalamic regions. Preliminary electrophysiological data obtained from patch-clamping neurons in brain slices have shown that bipolar neurons in the lateral septal organ responded to photostimulation comparable with mammalian ipRGC, particularly by showing depolarization and a delayed, slow response to directed light stimulation. Utilizing real-time reverse-transcription PCR, it was found that all 3 photopigments showed significantly increased gene expression in the septal-hypothalamic regions in chicks on the third day after being transferred to long-day photoperiods. Each dissected region contained structures previously proposed to have DBP. The highly significant increased gene expression for all 3 photopigments on the third, long-day photoperiod in brain regions proposed to contain 4 structures with DBP suggests that all 3 types of DBP (melanopsin, neuropsin, and vertebrate ancient opsin) in more than one neural site in the septal-hypothalamic area are involved in reproductive function. The neural response to light of at least 2 of the proposed DBP in the septal/hypothalamic region resembles the primitive, functional, sensory ipRGC well characterized in mammals.
- Prolonged Mechanical Stretch Initiates Intracellular Calcium Oscillations in Human Mesenchymal Stem Cells. [JOURNAL ARTICLE]
- PLoS One 2014; 9(10):e109378.
Mesenchymal stem cells (MSCs) are a promising candidate for cell-based therapy in regenerative medicine. These stem cells can interact with their mechanical microenvironment to control their functions. External mechanical cues can be perceived and transmitted into intracellular calcium dynamics to regulate various cellular processes. Recent studies indicate that human MSCs (hMSCs) exhibit a heterogeneous nature with a subset of hMSCs lacking spontaneous calcium oscillations. In this study, we studied whether and how external mechanical tension can be applied to trigger and restore the intracellular calcium oscillation in these hMSCs lacking spontaneous activities. Utilizing the fluorescence resonance energy transfer (FRET) based calcium biosensor, we found that this subpopulation of hMSCs can respond to a prolonged mechanical stretch (PMS). Further results revealed that the triggering of calcium oscillations in these cells is dependent on the calcium influx across the plasma membrane, as well as on both cytoskeletal supports, myosin light chain kinase (MLCK)-driven actomyosin contractility, and phospholipase C (PLC) activity. Thus, our report confirmed that mechanical tension can govern the intracellular calcium oscillation in hMSCs, possibly via the control of the calcium permeability of channels at the plasma membrane. Our results also provide novel mechanistic insights into how hMSCs sense mechanical environment to regulate cellular functions.
- Clinical and nerve conduction study correlation in patients of diabetic neuropathy. [Journal Article]
- J Assoc Physicians India 2014 Jan; 62(1):24-7.
1) To study types of neuropathy in Type 2 diabetes. 2) To correlate clinical features of peripheral neuropathy with nerve conduction study in Type 2 diabetes.A total of 50 diabetics, whose onset of diabetes after the age of 30 years were studied from Dr. D. Y. Patil hospital and research centre. Type 2 Diabetes mellitus with symptom suggestive of peripheral neuropathy were studied and included. Chronic alcoholic, peripheral neuropathy due to any other known cause were excluded. METHOD OF COLLECTION OF DATA: History of symptoms like paraesthesia like tingling sensation, burning feet, hyperaesthesia, foot ulcer, history of weakness and gait abnormality was noted. Complete central nervous system examination was performed to look for signs such as diminished ankle jerk, diminished power. Sensory examination for loss of light touch, superficial pain, temperature sense, vibration and joint position was done. Nerve conduction studies were performed using Clarity Octopus NCV/EMG machine. Written and informed consent from patient were taken.1) 46 patients i.e. 92% presented with complaints of tingling sensation and 32 patients i.e. 64% had burning feet. 2) 29 patients i.e. 58% have diminished ankle jerk, 29 patients i.e. 58% have diminished or loss of vibration sense, in 21 patients i.e. 42% patients have diminished light touch and 20 patients i.e. 40% patients have loss of joint position senses. 3) NCV performed on 50 patients of diabetic neuropathy out of which all patients i.e. 100% had involvement of lower limb and only 24 patients i.e. 48% had involvement of upper limb also. 4) Involvement of tibial and sural nerve is more common i.e. 86% and 82% respectively. 5) 42 patients i.e. 84% found to have distal symmetrical polyneuropathy, 2 patients i.e. 4% had isolated tibial nerve involvement, 4 patients i.e. 8% had pure sensory sural nerve involvement, and only 1 patient each of isolated medial and plantar nerve involvement.Distal symmetrical polyneuropathy is most common form of diabetic neuropathy. Involvement of tibial and sural nerve is more common in diabetic neuropathy.
- Fungal photobiology: visible light as a signal for stress, space and time. [JOURNAL ARTICLE]
- Curr Genet 2014 Oct 17.
Visible light is an important source of energy and information for much of life on this planet. Though fungi are neither photosynthetic nor capable of observing adjacent objects, it is estimated that the majority of fungal species display some form of light response, ranging from developmental decision-making to metabolic reprogramming to pathogenesis. As such, advances in our understanding of fungal photobiology will likely reach the broad fields impacted by these organisms, including agriculture, industry and medicine. In this review, we will first describe the mechanisms by which fungi sense light and then discuss the selective advantages likely imparted by their ability to do so.
- Spectral method for fast measurement of twisted nematic liquid crystal cell parameters. [Journal Article]
- Appl Opt 2014 Aug 10; 53(23):5230-7.
We present an experimental approach for the fast measurement of twisted nematic (TN) liquid crystal (LC) cells' parameters. It is based on the spectral measurements of the light transmitted by the system polarizer-reference wave plate-LC cell-analyzer. The cell parameters are obtained by fitting the theoretical model to the experimental data. This method allows determining the rubbing angle, the twist angle and its sense, and the spectral dispersion of the LC cell retardation, simultaneously, with few measurements and without the need of applying voltage or any specific analytical conditions. The method is validated by characterizing two different TN cells with retardations of about 0.91 and 1.85 μm. The birefringence relative error is less than 1.3%.
- Assessment of light touch sensation in the hands of systemic sclerosis patients. [Journal Article]
- Clinics (Sao Paulo) 2014 Sep; 69(9):585-8.
Systemic sclerosis is a relatively rare connective tissue disorder characterized by severe and progressive fibrosis of the skin. Due to the current lack of available information on this subject, the aim of the present study was to assess light touch sensations in the hands of patients with systemic sclerosis.We completed a cross-sectional comparative study. Light touch sensations were evaluated in 30 individuals, including 15 patients with systemic sclerosis who exhibited changes in the dermis of their hands without loss of the distal phalanx and 15 subjects who did not exhibit changes in the upper limbs (control group). The groups were age- and sex-matched. Tactile sensory evaluations were performed using the Semmes-Weinstein monofilament test and the two-point discrimination test.Statistically significant differences were found between groups in the monofilament test. The study group had lower scores across all points of the hand when compared with the control group. Differences were also found when dominant and non-dominant hands were compared (p<0.05). Statistically significant differences were found between groups for a subset of the assessed points in the two-point discrimination test.The results of a monofilament test showed that tactile sensation, specifically light touch and deep pressure sensations, is altered in the hands of systemic sclerosis patients.
- A neural interface provides long-term stable natural touch perception. [Journal Article]
- Sci Transl Med 2014 Oct 8; 6(257):257ra138.
Touch perception on the fingers and hand is essential for fine motor control, contributes to our sense of self, allows for effective communication, and aids in our fundamental perception of the world. Despite increasingly sophisticated mechatronics, prosthetic devices still do not directly convey sensation back to their wearers. We show that implanted peripheral nerve interfaces in two human subjects with upper limb amputation provided stable, natural touch sensation in their hands for more than 1 year. Electrical stimulation using implanted peripheral nerve cuff electrodes that did not penetrate the nerve produced touch perceptions at many locations on the phantom hand with repeatable, stable responses in the two subjects for 16 and 24 months. Patterned stimulation intensity produced a sensation that the subjects described as natural and without "tingling," or paresthesia. Different patterns produced different types of sensory perception at the same location on the phantom hand. The two subjects reported tactile perceptions they described as natural tapping, constant pressure, light moving touch, and vibration. Changing average stimulation intensity controlled the size of the percept area; changing stimulation frequency controlled sensation strength. Artificial touch sensation improved the subjects' ability to control grasping strength of the prosthesis and enabled them to better manipulate delicate objects. Thus, electrical stimulation through peripheral nerve electrodes produced long-term sensory restoration after limb loss.