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1.
Environ Sci Pollut Res Int ; 31(29): 42461-42475, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38874754

ABSTRACT

Leading phytopathological research is focused on managing seed-borne pathogens of rice through the utilization of engineered nanomaterials. Herein, blue laser-induced topo-morphologically nano-advanced copper salicylates (Cu-SA) (Cu/SA in 1:1 and 1:2 ratio) were prepared and evaluated for their augmented antifungal potential along seed invigoration effects in contrast to their prepared sonicated formulations. Laser disintegration on the Cu-SA (Cu/SA in 1:1 and 1:2 ratio) was achieved with high degree of success and precision using blue laser, which yielded uniformly distributed spherical nanoparticles with a narrow size distribution and better crystallinity than aqua-dispersed sonicated formulations. In vitro antifungal evaluation against seed-borne fungi of rice viz. Fusarium verticillioides and Fusarium fujikuroi revealed multiple times the augmented potential of laser-disintegrated nanoformulations (l-CuSA) than sonicated (s-CuSA) and bulk samples. Laser-induced nano-sodium bis(2-oxobenzoato)cuprate (II) (l-CuSA2) with Cu/SA in 1:2 ratio was the best to inhibit the in vitro fungal growth. Ultra-micrographs and fungal double-staining assay further rationalized the membrane disruption as the mode of action for the fungitoxicity. Nanopriming of fungal infested rice seeds with l-CuSA2 at 2500 µg/mL for 8 h showed the maximum reduction of seed rot (80.43%) and seedling blight (63.15%) with respect to control (untreated). The seed-invigorating factors of l-CuSA2 nanoprimed seeds were enhanced to maximum extent and showed the highest per cent germination (35.29%), shoot length (11.42%), root length (21.14%), dry weight (75.43%) and vigour index (81.04%) over the control. Inclusively, the seed nanopriming with l-CuSA2 proved as agro-compatible hypo-toxic semi natural nanoplatform for sustainable agriculture.


Subject(s)
Copper , Nanoparticles , Oryza , Salicylic Acid , Seeds , Oryza/microbiology , Copper/chemistry , Copper/pharmacology , Nanoparticles/chemistry , Lasers , Fusarium/drug effects , Antifungal Agents/pharmacology , Plant Diseases/microbiology , Plant Diseases/prevention & control
2.
Orthod Craniofac Res ; 2024 Apr 05.
Article in English | MEDLINE | ID: mdl-38577813

ABSTRACT

OBJECTIVES: The primary objective of this study was to assess the validity of the KPG index in predicting the difficulty of treatment involving impacted maxillary canines. The secondary objective was to assess the reliability and reproducibility of the index. MATERIALS AND METHODS: A retrospective study was conducted on 96 maxillary impacted canines (MIC) in 60 patients aged 13-35 years. Cone-beam computed tomography (CBCT) scans were used to predict the treatment difficulty of MIC using the KPG index. Patient case files were assessed for the actual difficulty encountered in treating MIC. Cohen's kappa correlation coefficient was used for intra-observer reliability and Kendell's W test was used for inter-observer reliability. Spearman's correlation coefficient test was used to assess the correlation between predicted and actual treatment. RESULTS: Easy and moderately difficult cases exhibited a moderate correlation between actual and predicted treatment outcomes, whereas difficult cases displayed a weak correlation. The perfect correlation was observed exclusively in extremely difficult cases. The intra-observer reliability for assessing CBCT scans using the KPG guide was found to be 0.88, and the inter-rater reliability was 0.94. CONCLUSION: The KPG index displayed 87%, 71%, 50% and 100% validity in easy, moderately difficult, difficult, and extremely difficult cases, respectively. This index showed good reliability and reproducibility. However, it is imperative to consider a multitude of other factors, including the patient's age, presence of associated root resorption in adjacent teeth, and duration of treatment, to make an informed decision between surgical exposure and extraction.

3.
Sci Rep ; 14(1): 6533, 2024 03 19.
Article in English | MEDLINE | ID: mdl-38503773

ABSTRACT

Nitrogen (N) and phosphorus (P) are vital for crop growth. However, most agricultural systems have limited inherent ability to supply N and P to crops. Biochars (BCs) are strongly advocated in agrosystems and are known to improve the availability of N and P in crops through different chemical transformations. Herein, a soil-biochar incubation experiment was carried out to investigate the transformations of N and P in two different textured soils, namely clay loam and loamy sand, on mixing with rice straw biochar (RSB) and acacia wood biochar (ACB) at each level (0, 0.5, and 1.0% w/w). Ammonium N (NH4-N) decreased continuously with the increasing incubation period. The ammonium N content disappeared rapidly in both the soils incubated with biochars compared to the unamended soil. RSB increased the nitrate N (NO3-N) content significantly compared to ACB for the entire study period in both texturally divergent soils. The nitrate N content increased with the enhanced biochar addition rate in clay loam soil until 15 days after incubation; however, it was reduced for the biochar addition rate of 1% compared to 0.5% at 30 and 60 days after incubation in loamy sand soil. With ACB, the net increase in nitrate N content with the biochar addition rate of 1% remained higher than the 0.5% rate for 60 days in clay loam and 30 days in loamy sand soil. The phosphorus content remained consistently higher in both the soils amended with two types of biochars till the completion of the experiment.


Subject(s)
Ammonium Compounds , Soil Pollutants , Soil/chemistry , Phosphorus , Sand , Clay , Nitrates , Nitrogen , Charcoal/chemistry , Soil Pollutants/analysis
4.
Sci Rep ; 13(1): 6286, 2023 Apr 18.
Article in English | MEDLINE | ID: mdl-37072395

ABSTRACT

The quantum properties of fluorescent nanodiamonds offer great promise for fabricating quantum-enabled devices for physical applications. However, the nanodiamonds need to be suitably combined with a substrate to exploit their properties. Here, we show that ultrathin and flexible glass (thickness 30 microns) can be functionalized by nanodiamonds and nano-shaped using intense femtosecond pulses to design cantilever-based nanomechanical hybrid quantum sensors. Thus fabricated ultrathin glass cantilevers show stable optical, electronic, and magnetic properties of nitrogen-vacancy centers, including well-defined fluorescence with zero-phonon lines and optically detected magnetic resonance (ODMR) near 2.87 GHz. We demonstrate several sensing applications of the fluorescent ultrathin glass cantilever by measuring acoustic pulses, external magnetic field using Zeeman splitting of the NV centers, or CW laser-induced heating by measuring thermal shifting of ODMR lines. This work demonstrates the suitability of the femtosecond-processed fluorescent ultrathin glass as a new versatile substrate for multifunctional quantum devices.

5.
Sci Rep ; 12(1): 8525, 2022 May 20.
Article in English | MEDLINE | ID: mdl-35595769

ABSTRACT

We demonstrate a dispersion-free wavefront splitting attosecond resolved interferometric delay line for easy ultrafast metrology of broadband femtosecond pulses. Using a pair of knife-edge prisms, we symmetrically split and later recombine the two wavefronts with a few tens of attosecond resolution and stability and employ a single-pixel analysis of interference fringes with good contrast using a phone camera without any iris or nonlinear detector. Our all-reflective delay line is theoretically analyzed and experimentally validated by measuring 1st and 2nd order autocorrelations and the SHG-FROG trace of a NIR femtosecond pulse. Our setup is compact, offers attosecond stability with flexibility for independent beam-shaping of the two arms. Furthermore, we suggest that our compact and in-line setup can be employed for attosecond resolved pump-probe experiments of matter with few-cycle pulses.

6.
Malays Orthop J ; 16(3): 61-69, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36589383

ABSTRACT

Introduction: Olecranon osteotomy is employed for the fixation of intraarticular distal humeral fractures. We conducted a prospective, randomised study comparing Chevron's osteotomy with olecranon osteotomy by a Gigli saw for exposure of the intraarticular distal humerus in terms of functional outcome and intra-operative ease of the surgery. Materials and methods: Thirty patients with skeletally mature AO/OTA type 13- B and 13-C distal humerus fractures were randomly allocated to Chevron's or Gigli saw groups. Each group consisted of a total of 15 patients. Both the groups were assessed on post-operative parameters including arm, shoulder or hand pain, ability to perform certain routine activities, tingling sensations and pain while sleeping. Results: In the Gigli saw group, 12 patients had no gross limitation of activity and 13 were able to perform moderate activities with ease. Similar results were observed in the Chevron's group. The mean difference between the two groups in Oxford Score was 0.60, within the 95% confidence interval and in line with QuickDASH-11 Score. Conclusion: Chevron's technique offers stability and better healing, providing a larger surface area for bone union. However, it is challenging and time-consuming. Also, literature suggests that the Gigli saw has multiple benefits, saves time and effort, and heals by switching blood supply from centrifugal to centripetal post-operatively. Our study suggests that both Chevron's technique and the use of the Gigli saw are effective in distal humeral intra-articular fractures as assessed by multiple parameters. Hence both techniques can be equally used depending on the surgeon's preference.

7.
In. Faculty of Medical Sciences, The University of the West Indies. 2020 National Health Research Conference: Advancing Health Research in Trinidad and Tobago. Port of Sapin, Caribbean Medical Journal, November 19, 2020. .
Non-conventional in English | MedCarib | ID: biblio-1353744

ABSTRACT

Lung cancer is one of the most common cause of mortality, highly attributed to an increase in tobacco use/ cigarette smoking. It ranks amongst the top 3 causes of cancer in Trinidad and Tobagonian men. The objective of this study is to the investigate the prevalence of Lung cancer in Trinidad and Tobago, its histological subtypes, demographics, predisposing risk factors and presenting stage. Additionally, comparison is made between current Lung cancer trends and those identified from previous studies. Our current findings is a more accurate representation of local trends, which can now provide foundational data that can be used to implement better approaches in the improvement of Lung cancer care in Trinidad and Tobago.


Subject(s)
Humans , Male , Trinidad and Tobago , Lung Neoplasms , Risk Factors , Mortality , Cigarette Smoking
8.
Opt Lett ; 45(18): 5266-5269, 2020 Sep 15.
Article in English | MEDLINE | ID: mdl-32932507

ABSTRACT

We introduce an ultra-thin attosecond optical delay line based on controlled wavefront division of a femtosecond infrared pulse after transmission through a pair of micrometer-thin glass plates with negligible dispersion effects. The time delay between the two pulses is controlled by rotating one of the glass plates from absolute zero to several optical cycles, with 2.5 as to tens of attosecond resolution with 2 as stability, as determined by interferometric self-calibration. The performance of the delay line is validated by observing attosecond-resolved oscillations in the yield of high harmonics induced by time delayed infrared pulses, in agreement with a numerical simulation for a simple model atom. This approach can be extended in the future for performing XUV-IR attosecond pump-probe experiments.

9.
Rev Sci Instrum ; 90(4): 043117, 2019 Apr.
Article in English | MEDLINE | ID: mdl-31043051

ABSTRACT

We demonstrate a simple and versatile nanomechanical force measuring setup with 1 nN precision in air and vacuum using a load cell of an ultra-microbalance. We validate stability, precision, and linearity of the load cell with simple tests. The setup is customized to measure stress-strain response of biomaterials (silk, leaf, and flower) and capillary force in fluids. We isolated an optical pull force induced by a Watt-level laser reflected from a mirror/solid surface in air, in addition to optical push force. Furthermore, we add an interferometric probe to directly measure nanoscale deflection of cantilever of the load cell in real-time, thus bypassing its conventional electromagnetic readout, to improve speed and precision of the instrument. We demonstrate nanomechanical force measurement in high vacuum with the same precision and employ radiation pressure to calibrate the load cell for various precision measurements.

10.
Am J Physiol Renal Physiol ; 315(6): F1833-F1842, 2018 12 01.
Article in English | MEDLINE | ID: mdl-30207172

ABSTRACT

The p66ShcA protein controls cellular responses to oxidative stress, senescence, and apoptosis. Here, we test the hypothesis that aging phenotype(s) commonly associated with the broad category of chronic kidney disease are accelerated in diabetic kidneys and linked to the p66ShcA locus. At the organ level, tissue stem cells antagonize senescent phenotypes by replacing old dysfunctional cells. Using established methods, we isolated a highly purified population of stem cell antigen-1-positive mesenchymal stem cells (Sca-1+ MSCs) from kidneys of wild-type (WT) and p66 knockout (p66 KO) mice. Cells were plated in culture medium containing normal glucose (NG) or high glucose (HG). Reactive oxygen species (ROS) metabolism was substantially increased in WT MSCs in HG medium in association with increased cell death by apoptosis and acquisition of the senescent phenotype. DNA microarray analysis detected striking differences in the expression profiles of WT and p66 KO-MSCs in HG medium. Unexpectedly, the analysis for p66 KO-MSCs revealed upregulation of Wnt genes implicated in self-renewal and differentiation. To test the in vivo consequences of constitutive p66 expression in diabetic kidneys, we crossed the Akita diabetic mouse with the p66KO mouse. Homozygous mutation at the p66 locus delays or prevents aging phenotype(s) in the kidney that may be precursors to diabetic nephropathy.


Subject(s)
Aging/metabolism , Diabetic Nephropathies/metabolism , Kidney/metabolism , Mesenchymal Stem Cells/metabolism , Src Homology 2 Domain-Containing, Transforming Protein 1/metabolism , Age Factors , Aging/genetics , Aging/pathology , Animals , Apoptosis , Cell Differentiation , Cell Proliferation , Cells, Cultured , Cellular Senescence , Diabetic Nephropathies/genetics , Diabetic Nephropathies/pathology , Disease Models, Animal , Glucose/metabolism , Kidney/pathology , Mesenchymal Stem Cells/pathology , Mice, Knockout , Phenotype , Reactive Oxygen Species/metabolism , Src Homology 2 Domain-Containing, Transforming Protein 1/deficiency , Src Homology 2 Domain-Containing, Transforming Protein 1/genetics , Stem Cell Niche , Wnt Signaling Pathway
11.
Musculoskelet Surg ; 102(1): 81-85, 2018 Apr.
Article in English | MEDLINE | ID: mdl-28956304

ABSTRACT

BACKGROUND: The role of vascular endothelial growth factor (VEGF) after ischaemic necrosis of the femoral head in Legg-Calve-Perthes disease (LCPD) has not been adequately studied in humans, especially in Indian population. Therefore, we aimed to evaluate the serum levels of VEGF-A in Indian children with various stages of LCPD and compare them with those of an age- and sex-matched control group of healthy children. METHODS: In this case-control study, we enrolled 42 children (below 14 years age) suffering from LCPD and 21 age- and sex-matched healthy controls. Patients were classified radiographically according to Waldenstrom's classification. Serum VEGF-A was estimated by sandwich enzyme-linked immunosorbent assay technique. The serum values were compared between the patient group and the control group, as well as between the Waldenstrom subgroups. Results were expressed as means with ranges or median with interquartile range. RESULTS: The mean age in the patient as well as the control group was 9 years (range 4-13 years). The median value (interquartile range) of serum VEGF-A was 162.5 pg/ml (673.75 pg/ml) in the patient group and 652 pg/ml (190.5 pg/ml) in the control group (p = 0.013). When compared between lower Waldenstrom stages (initial stage + stage of fragmentation) and higher Waldenstrom stages (re-ossification stage + stage of healing), the mean values of serum VEGF-A were 464.7 pg/ml (range 0-2211 pg/ml) and 301.1 pg/ml (range 0-1910 pg/ml), respectively (p = 0.305). CONCLUSIONS: VEGF is under-expressed in Indian children suffering from LCPD. As VEGF acts as a key regulator of endochondral ossification, our finding may open new therapeutic approaches to the disease. Also, serum VEGF may act as a valuable marker for the follow-up of the disease. Our study also provides baseline data about serum VEGF-A levels in Indian cohort of LCPD patients. Future multi-centre studies are warranted with a larger sample size to fully appreciate the patho-physiological changes in VEGF occurring in LCPD.


Subject(s)
Legg-Calve-Perthes Disease/blood , Legg-Calve-Perthes Disease/diagnosis , Vascular Endothelial Growth Factor A/blood , Adolescent , Adult , Biomarkers/blood , Case-Control Studies , Child , Child, Preschool , Female , Humans , India/epidemiology , Legg-Calve-Perthes Disease/ethnology , Male , Predictive Value of Tests , Sensitivity and Specificity , Severity of Illness Index
12.
Nat Mater ; 16(9): 938-945, 2017 09.
Article in English | MEDLINE | ID: mdl-28805825

ABSTRACT

Spider silk is a tough, elastic and lightweight biomaterial, although there is a lack of tools available for non-invasive processing of silk structures. Here we show that nonlinear multiphoton interactions of silk with few-cycle femtosecond pulses allow the processing and heterostructuring of the material in ambient air. Two qualitatively different responses, bulging by multiphoton absorption and plasma-assisted ablation, are observed for low- and high-peak intensities, respectively. Plasma ablation allows us to make localized nanocuts, microrods, nanotips and periodic patterns with minimal damage while preserving molecular structure. The bulging regime facilitates confined bending and microwelding of silk with materials such as metal, glass and Kevlar with strengths comparable to pristine silk. Moreover, analysis of Raman bands of microwelded joints reveals that the polypeptide backbone remains intact while perturbing its weak hydrogen bonds. Using this approach, we fabricate silk-based functional topological microstructures, such as Mobiüs strips, chiral helices and silk-based sensors.

13.
Mycorrhiza ; 27(2): 95-108, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27639577

ABSTRACT

Terrestrial orchids depend on orchid mycorrhizal fungi (OMF) as symbionts for their survival, growth and nutrition. The ability of OMF from endangered orchid species to compete for available resources with OMF from common species may affect the distribution, abundance and therefore conservation status of their orchid hosts. Eight symbiotically effective OMF from endangered and more common Caladenia species were tested for their ability to utilise complex insoluble and simple soluble carbon sources produced during litter degradation by growth with different carbon sources in liquid medium to measure the degree of OMF variation with host conservation status or taxonomy. On simple carbon sources, fungal growth was assessed by biomass. On insoluble substrates, ergosterol content was assessed using ultra-performance liquid chromatography (UPLC). The OMF grew on all natural materials and complex carbon sources, but produced the greatest biomass on xylan and starch and the least on bark and chitin. On simple carbon sources, the greatest OMF biomass was measured on most hexoses and disaccharides and the least on galactose and arabinose. Only some OMF used sucrose, the most common sugar in green plants, with possible implications for symbiosis. OMF from common orchids produced more ergosterol and biomass than those from endangered orchids in the Dilatata and Reticulata groups but not in the Patersonii and Finger orchids. This suggests that differences in carbon source utilisation may contribute to differences in the distribution of some orchids, if these differences are retained on site.


Subject(s)
Carbon/metabolism , Endangered Species , Mycorrhizae/physiology , Orchidaceae/microbiology , Chromatography, Liquid , Ergosterol/chemistry , Ergosterol/metabolism , Mycorrhizae/classification
14.
Br Dent J ; 220(11): 565-6, 2016 Jun 10.
Article in English | MEDLINE | ID: mdl-27283558

ABSTRACT

Situational judgement tests (SJTs) have been shown to be reliable and valid tools for assessing non-academic attributes across numerous healthcare professions. However, within the context of selection into dental foundation training (DFT) in the UK the introduction of an SJT is relatively new. This expert opinion highlights four key considerations regarding the DFT SJT in order to inform further debate amongst researchers and stakeholders. We clarify that SJTs measure non-academic attributes important for success in dental training, and that their context and content must be updated regularly to ensure their relevance, realism and fairness to current applicants. We outline that SJTs are efficient and cost-effective for high volume selection in the long term, in comparison to face-to-face interviews. Finally we summarise the value of practice material being available for high-stakes SJTs, such as the DFT SJT. Implications for practice are discussed throughout.


Subject(s)
Judgment , School Admission Criteria , Achievement , Education, Dental , Humans , Reproducibility of Results
15.
J Obstet Gynaecol ; 36(2): 187-91, 2016.
Article in English | MEDLINE | ID: mdl-26368274

ABSTRACT

The July phenomenon refers to a change in patient outcomes within teaching hospitals with the arrival of new and inexperienced house staff at the start of the academic year (July to June). In our obstetric triage unit we retrospectively evaluated the door to disposition time (DTDT) for 1817 patients who presented across July, December and May of academic years 2009-2010 and 2010-2011. DTDT was examined for three visit levels: non-urgent, urgent and emergent. No significant differences in disposition time were found for emergent visits. For urgent visits the median DTDT significantly decreased from 171 min in July to 155 min in December and 135 min in May (p < 0.001). Similarly for non-urgent visits, the median DTDT was greater during July than May (179 min vs. 133 min; p < 0.05). Electronic medical records (EMRs) were implemented in November 2010. Following the introduction of EMR shorter DTDT was seen in December 2010 versus December 2009 (median, 171 min vs. 150 min; p < 0.05), respectively. Our findings suggest a 'July Phenomenon' of greater disposition intervals for urgent and non-urgent obstetric triage visits across the academic year. Additionally the use of EMRs may facilitate patient flow through the OB triage unit.


Subject(s)
Hospitals, Teaching/statistics & numerical data , Obstetrics/statistics & numerical data , Patient Acuity , Triage/statistics & numerical data , Electronic Health Records , Emergencies , Female , Humans , Office Visits , Pregnancy , Retrospective Studies , Time Factors
17.
Biomed Opt Express ; 6(12): 4694-704, 2015 Dec 01.
Article in English | MEDLINE | ID: mdl-26713187

ABSTRACT

In this work, we demonstrate that ultrafast laser irradiation could selectively disrupt vascular endothelium of zebrafish embryos in vivo. Ultrafast lasers minimize the collateral damage in the vicinity of the laser focus and eventually reduce coagulation in the tissues. We have also found that the threshold fluence for lesion formation of the vascular endothelium strongly depends on the developmental stage of the embryos. The threshold laser fluence required to induce apparent lesions in the vascular structure for Somite 14, 20 and 25 stages is about 5 J/cm(2) ~7 J/cm(2), which is much lower than that for the later development stages of Prim 16 and Prim 20 of 30 J/cm(2) ~50 J/cm(2). The proposed method for treating the vascular cord of zebrafish embryos in the early stage of development has potential as a selective and effective method to induce a fatal lesion in the vascular endothelium without damaging the developed blood vessels.

18.
Opt Express ; 23(15): 19854-62, 2015 Jul 27.
Article in English | MEDLINE | ID: mdl-26367645

ABSTRACT

We have investigated the effect of the dynamics of crater size on the poly(dimethylsiloxane) (PDMS) surface morphology in fs-laser micro-processing. PDMS surface was processed with varying both inter-pulse interval and inter-spot distance between successive laser pulses. With keeping the interval of 5 ms crater shape is round even if the spot is overlapped in space. But decreasing the interval to 0.02 ms the shape of the crater is no longer round. Decreasing the inter-distance between the craters results in roughened surface morphology even at time intervals of 5 ms. Temporal dependence of single-shot fs-laser induced crater size was measured as a function of time delay. Within 0.1 ms after pulse irradiation with a fluence of 4.8 J/cm2 on PDMS surface the crater size has reached to its maximum values and then decreased with a time constant of about 0.3 ms. The surface morphology after fs-laser pulse irradiation is strongly dependent on not only inter-spot distance between successive laser pulse but also their inter-pulse intervals. By proposing a theoretical model on their dynamic features, we will try to explain the current observation in quantitatively.

19.
Tissue Antigens ; 84(5): 465-70, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25284481

ABSTRACT

Polymorphism of interferon regulatory factor 5 (IRF5), a latent transcription factor gene has been associated with various auto-immune diseases. Our aim was to study the IRF5rs2004640 gene polymorphism and its association with disease susceptibility, disease phenotype and treatment response in South Indian Tamil patients with rheumatoid arthritis (RA).The study was conducted on 217 RA patients fulfilling the American College of Rheumatology (ACR) 2010 criteria and 482 healthy controls (HCs) without family history of autoimmune disease. The IRF5rs2004640 genotyping was performed using a TaqMan 5' allelic discrimination assay. We found that the IRF5rs2004640T allele [P < 0.0001, odds ratio (OR) 3.25, 95% confidence interval (CI) 2.55-4.12] and TT genotype (P < 0.0001, OR 4.60, 95% CI 3.23-6.57) were significantly more frequent in RA patients as compared with HCs. No association was found between IRF5rs2004640 polymorphism, clinical manifestations, autoantibody profile and treatment response. IRF5rs2004640 T (mutant) allele may be a susceptibility factor conferring risk for RA in South Indian Tamils, whereas G allele (wild type) may be protective.


Subject(s)
Alleles , Arthritis, Rheumatoid/genetics , Genetic Predisposition to Disease , Interferon Regulatory Factors/genetics , Polymorphism, Single Nucleotide , Adult , Arthritis, Rheumatoid/epidemiology , Arthritis, Rheumatoid/ethnology , Female , Follow-Up Studies , Humans , India/epidemiology , India/ethnology , Male , Middle Aged
20.
Lasers Med Sci ; 29(4): 1417-27, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24570086

ABSTRACT

Nonlinear multiphoton absorption induced by focusing near infrared (NIR) femtosecond (fs) laser pulses into a transparent cornea allows surgery on neovascular structures with minimal collateral damage. In this report, we introduce an fs laser-based microsurgery for selective treatment of rat corneal neovascularizations (in vivo). Contiguous tissue effects are achieved by scanning a focused laser pulse below the corneal surface with a fluence range of 2.2-8.6 J/cm(2). The minimal visible laser lesion (MVL) threshold determined over the corneal neovascular structures was found to be 4.3 J/cm(2). Histological and optical coherence tomography examinations of the anterior segment after laser irradiations show localized degeneration of neovascular structures without any unexpected change in adjacent tissues. Furthermore, an approximately 30 % reduction in corneal neovascularizations was observed after 5 days of fs laser exposure. The femtosecond laser is thus a promising tool for minimally invasive intrastromal surgery with the aid of a significantly smaller and more deterministic photodisruptive energy threshold for the interaction between the fs laser pulse and corneal neovascular structures.


Subject(s)
Cornea/blood supply , Corneal Neovascularization/surgery , Laser Therapy/methods , Lasers, Solid-State/therapeutic use , Animals , Cornea/pathology , Cornea/surgery , Microsurgery , Rats
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