Spectrophotometric Online Detection of Drinking Water Disinfectant: A Machine Learning Approach.

The spectra fingerprint of drinking water from a water treatment plant (WTP) is characterised by a number of light-absorbing substances, including organic, nitrate, disinfectant, and particle or turbidity. Detection of disinfectant (monochloramine) can be better achieved by separating its spectra from the combined spectra. In this paper, two major focuses are (i) the separation of monochloramine spectra from the combined spectra and (ii) assessment of the application of the machine learning algorithm in real-time detection of monochloramine. The support vector regression (SVR) model was developed using multi-wavelength ultraviolet-visible (UV-Vis) absorbance spectra and online amperometric monochloramine residual measurement data. The performance of the SVR model was evaluated by using four different kernel functions. Results show that (i) particles or turbidity in water have a significant effect on UV-Vis spectral measurement and improved modelling accuracy is achieved by using particle compensated spectra; (ii) modelling performance is further improved by compensating the spectra for natural organic matter (NOM) and nitrate (NO3) and (iii) the choice of kernel functions greatly affected the SVR performance, especially the radial basis function (RBF) appears to be the highest performing kernel function. The outcomes of this research suggest that disinfectant residual (monochloramine) can be measured in real time using the SVR algorithm with a precision level of ± 0.1 mg L-1.

Real-world visual outcomes in patients with neovascular age-related macular degeneration receiving aflibercept at fixed intervals as per UK licence.

IMPORTANCE: To assess the impact of injection frequency on visual outcomes in patients with neovascular age-related macular degeneration (nAMD) treated with intravitreal aflibercept. BACKGROUND: The UK licence for treatment of nAMD with aflibercept is based on the VIEW protocol. We tested the hypothesis that patients receiving fewer than the eight recommended injections in the first year would experience worse visual outcomes. DESIGN: Retrospective, single-centre observational study. PARTICIPANTS: There were 42 eyes from 42 patients included. METHODS: Fight Retinal Blindness! software was used to record real-world outcomes of all treatment-naïve eyes receiving aflibercept for at least 1 year. MAIN OUTCOME MEASURES: Visual acuity (VA) at 1 year in eyes which received the recommended eight injections versus those receiving seven or fewer injections. RESULTS: There were 21 eyes (50%) that received the recommended eight aflibercept injections in the first year of treatment, whilst 14 eyes received seven injections, five received six injections and two received only five injections, with median VA change +7.0, +5.0, -4.0 and -6.5 LogMAR letters, respectively. Those eyes receiving seven or fewer injections had worse baseline vision. The main reasons for patients being undertreated were insufficient clinic capacity and non-attendance due to illness. CONCLUSIONS AND RELEVANCE: Patients in the real-world receiving aflibercept for nAMD at fixed intervals as per UK licence could achieve similar visual improvement at 1 year compared with phase III clinical trials. Undertreated patients had worse visual outcomes. Measures need to be introduced to increase clinic capacity and closely follow non-attenders to improve future outcomes.

Confocal fluorescence polarization microscopy for linear unmixing of spectrally similar labels.

Studies of biological samples often call for simultaneous identification of multiple molecular or structural components. Multiple labelling fluorescence techniques are a powerful way of achieving this. However, the ability to distinguish a number of fluorescent probes unambiguously can be restricted by the fact that fluorescence spectra are generally broad and overlapping. Recently a technique known as linear unmixing has been combined with spectral imaging to discriminate between multiple fluorophores. In this study a scheme is proposed whereby fluorescence polarization information is used to expand the capability of the linear unmixing technique to accommodate additional fluorescent probes. As a proof-of-concept, it is shown that this polarization-based technique can be used to divide the signals generated by two spectrally similar fluorescent probes into their separate components.

Assessing attitudes of patient-centred care among students in international chiropractic educational programs: a cross-sectional survey.

Background: Patient-centred care is internationally recognized as a foundation of quality patient care. Attitudes of students towards patient-centred care have been assessed in various health professions. However, little is known how chiropractic students' attitudes towards patient-centred care compare to those of other health professions or whether they vary internationally, and between academic programs. Objective: To assess the association of select variables on student attitude towards patient-centred care among select chiropractic programs worldwide. Methods: We conducted a cross-sectional study using the Patient-Practitioner Orientation Scale (PPOS) to assess students' patient-centred attitudes towards the doctor-patient relationship. Eighteen items were scored on a 1 to 6 Likert scale; higher scores indicating more patient-centredness. All students from seven chiropractic educational programs worldwide were invited to complete an online survey. Results were analyzed descriptively and inferentially for overall, sharing and caring subscales. General linear regression models were used to assess the association of various factors with PPOS scores. Results: There were 1858 respondents (48.9% response rate). Student average age was 24.7 (range = 17-58) years and 56.2% were female. The average overall PPOS score was 4.18 (SD = 0.48) and average sharing and caring subscale scores were 3.89 (SD = 0.64) and 4.48 (SD = 0.52), respectively. There were small but significant differences in all PPOS scores by gender, age, and program. Year/semester of study within a program typically was not associated with scores, neither was history of previous chiropractic care nor having family members who are health professionals. Conclusion: This is the first international study assessing students' attitudes of patient-centred care in chiropractic educational programs. We found small but significantly different PPOS scores between chiropractic programs worldwide that did not change across year/semester of study. Scores tended to be lower than those reported among medical students. Observed differences may be related to curricular content, extent of patient exposure and/or regional cultural realities.

Laser confocal endomicroscopy as a novel technique for fluorescence diagnostic imaging of the oral cavity.

Malignancies of the oral cavity are conventionally diagnosed by white light endoscopy, biopsy, and histopathology. However, it is often difficult to distinguish between benign and premalignant or early lesions. A laser confocal endomicroscope (LCE) offers noninvasive, in vivo surface and subsurface fluorescence imaging of tissue. We investigate the use of an LCE with a rigid probe for diagnostic imaging of the oral cavity. Fluorescein and 5-aminolevulinic acid (ALA) were used to carry out fluorescence imaging in vivo and on resected tissue samples of the oral cavity. In human subjects, ALA-induced protoporphyrin IX (PpIX) fluorescence images from the normal tongue were compared to images obtained from patients with squamous cell carcinoma (SCC) of the tongue. Using rat models, images from normal rat tongues were compared to those from carcinogen-induced models of SCC. Good structural images of the oral cavity were obtained using ALA and fluorescein, and morphological differences between normal and lesion tissue can be distinguished. The use of a pharmaceutical-grade solvent Pharmasolve enhanced the subsurface depth from which images can be obtained. Our initial results show that laser confocal fluorescence endomicroscopy has potential as a noninvasive optical imaging method for the diagnosis of oral cavity malignancies.

Physical activity and its correlation to diabetic retinopathy.

PURPOSE: The lack of physical activity, along with obesity, smoking, hypertension and hyperglycaemia are considered as risk factors for the occurrence of diseases such as diabetes. Primary objective of the study was to investigate potential correlation between physical activity and diabetic retinopathy. PATIENTS AND METHODS: Three hundred and twenty patients were included in the study: 240 patients with diabetes type 2 (80 patients with mild to moderate non-proliferative diabetic retinopathy, 80 patients with severe to very severe non-proliferative diabetic retinopathy and 80 ones with proliferative diabetic retinopathy) were compared with 80 non-diabetic patients (control group). Physical activity of patients was assessed by the international physical activity questionnaire (IPAQ, 2002). HbA1c and BMI were also measured in diabetic patients. Group comparisons were attempted for levels of physical activity and sedentary behavior. RESULTS: Total physical activity was decreased in patients with severe to very severe non-proliferative diabetic retinopathy and proliferative diabetic retinopathy as compared to patients with mild to moderate non-proliferative diabetic retinopathy and to the control group (p<0.05). Significant negative correlation was detected between HbA1c levels, BMI and physical activity (both p<0.05). Moreover, significant negative correlation between the severity of diabetic retinopathy and physical activity has been demonstrated (p<0.05). CONCLUSIONS: Increased physical activity is associated with less severe levels of diabetic retinopathy, independent of the effects of HbA1c and BMI.

Risk-based management of drinking water safety in Australia: Implementation of health based targets to determine water treatment requirements and identification of pathogen surrogates for validation of conventional filtration.

The safety of drinking water in Australia is ensured using a risk management framework embedded within the Australian Drinking Water Guidelines (ADWG). This framework includes elements for hazard identification, risk assessment, risk mitigation, verification of barrier performance and monitoring for any changes to the hazards that influence source water quality. The next revision of the ADWG will incorporate Health-Based Targets (HBTs) for achieving microbiologically safe drinking water. This incorporates Quantitative Microbial Risk Assessment and the metric of Disability Adjusted Life Year (DALY) to define safety, with a target of 1 × 10- 6 Disability Adjusted Life Year (1 microDALY) set as the maximum tolerable disease burden from drinking water, which in the case of Cryptosporidium is < 1.3 × 10- 5 oocysts/L. The resulting product water specification, in combination with knowledge of pathogen challenges in source waters, allows the determination of the treatment requirements to ensure public safety. The ADWG revision provides default removal values for Cryptosporidium for particular treatment processes, such as conventional coagulation and dual media filtration. However, these values are based on assumptions regarding treatment plant design, operation and water quality. To properly manage risk and demonstrate compliance with the guidelines, water utilities may need to validate treatment performance for Cryptosporidium removal. A particular limitation is the absence of Cryptosporidium surrogates for full-scale filter validation. This paper will provide an overview of risk-based management of drinking water safety in Australia, the development of health-based targets for microbial pathogens and the evaluation of Cryptosporidium surrogates for conventional coagulation and dual media filtration.

Not at Imminent Risk. A Systematic Literature Review.

BACKGROUND: Suicide is a pervasive and complex issue that can challenge counselors through the course of their careers. Research and practice focus heavily on crisis management and imminent risk rather than early intervention strategies. Early intervention strategies can assist counselors working with clients who have suicidal ideation, but are not at imminent risk, or with clients whose risk factors identify them as having a stronger trajectory for suicidal ideation. AIMS: This systematic literature review examines the current literature on working with clients with suicidal ideation who are not at imminent risk, to ascertain the types of information and strategies available to counselors working with this client group. METHOD: An initial 622 articles were identified for analysis and from these 24 were included in the final review, which was synthesized using a narrative approach. RESULTS: Results indicate that research into early intervention strategies is extremely limited. CONCLUSION: It was possible to describe emergent themes and practice guidelines to assist counselors working with clients with suicidal ideation but not at imminent risk.

Confocal endomicroscopic imaging of normal and neoplastic human tongue tissue using ALA-induced-PPIX fluorescence: a preliminary study.

Confocal endomicroscopy is a novel and non-invasive microscopic technique that enables surface and subsurface imaging of living tissues or cells in vivo. The purpose of this study was to assess the possibility of utilizing a rigid confocal endomicroscope (RCE) system developed for detecting morphological changes in living normal and neoplastic human tongue tissue in combination with 5-aminolevulinic acid (ALA)-induced endogenous protoporphyrin IX (PPIX) fluorescence. Three patients with squamous cell carcinoma (SCC) of the tongue were examined using the novel RCE system with the excitation wavelength at 488 nm from an argon-ion laser and the detection wavelengths of the tissue fluorescence above 515 nm. Patients were topically applied with 0.4% of 5-ALA rinsing solution to the oral mucosa for approximately 15 min, and then the confocal endomicroscopic imaging of tissue PPIX fluorescence was performed on the lesion sites of the tongue after an optimal incubation period of 90-120 min. For comparison purposes, ALA-PPIX fluorescence confocal endomicroscopic imaging was also carried out on the normal sites of the tongue in vivo from two healthy volunteers. Image distortions due to tissue motion can be minimized using a specially designed tissue stabilizer attached to the RCE probe. Good quality ALA-mediated confocal fluorescence images of the tongue can be acquired in real-time, providing well-defined micro-morphological structures (e.g., filiform papillae, keratinized epithelium and fungiform papillae) of the tongue in vivo. Changes of tissue structures in oral tissue associated with cancer transformation can also be clearly identified using the RCE imaging. Preliminary results obtained in this study suggest that ALA-mediated rigid confocal endomicroscopy may have a significant potential for the rapid, non-invasive diagnosis and evaluation of early oral cancers in vivo.

Efficacy of anterior chamber decompression in controlling early intraocular pressure spikes after uneventful phacoemulsification.

PURPOSE: To determine the efficacy of anterior chamber decompression in the management of intraocular pressure (IOP) spikes in the early period after uneventful phacoemulsification. SETTING: Royal Free Hospital, Department of Ophthalmology, Royal Free and University College London Medical School, London, United Kingdom. METHODS: This prospective case series comprised 11 consecutive patients with otherwise healthy eyes who an IOP of at least 40 mm Hg 4 to 6 hours after phacoemulsification. After anterior chamber decompression, the IOP was measured at 0, 15, 30, 45, and 60 minutes or until it exceeded 40 mm Hg. RESULTS: The mean IOP 4 to 6 hours postoperatively was 47.09 mm Hg +/- 7.92 (SD) (range 40 to 68 mm Hg). After decompression, the IOP dropped significantly to a mean of 4.73 +/- 3.00 mm Hg at 0 minutes (P<.001) and then increased progressively to 23.36 +/- 10.80 mm Hg at 15 minutes (P<.001), 33.82 +/- 11.74 mm Hg at 30 minutes (P=.005), 35.00 +/- 6.53 mm Hg at 45 minutes (P=.015), and 38.50 +/- 2.51 mm Hg at 60 minutes (P=.041). CONCLUSIONS: Marked IOP spikes developed in eyes without glaucoma or ocular hypertension after uneventful phacoemulsification. Anterior chamber decompression immediately lowered IOP, but the effect was transient.

Carcinoid tumor originating in a horseshoe kidney.

An atypical carcinoid tumor originating in the horseshoe kidney of a 39-year-old man is reported. The tumor showed cytological atypia, increased mitotic rate and histological signs of mucinous differentiation and osseous metaplasia. Even though there were distant metastases, the patient survived partial nephrectomy including resection of the primary tumor for four years. The review of literature shows that carcinoid tumors originate some 60 to 85 times more often in horseshoe kidneys than in normal kidneys. The clinical course of renal carcinoid tumors is highly variable.

Choroidal naevi complicated by choroidal neovascular membrane and outer retinal tubulation.

AIMS: To present the outcomes of a series of patients with choroidal neovascular membrane (CNV) secondary to a choroidal naevus and report the presence of outer retinal tubulation. METHODS: In this retrospective series, patients underwent a complete clinical and imaging assessment (fundus photo, fluorescein angiography and optical coherence tomography) and were observed or managed with intravitreal anti-VEGF injections dependent on whether visual acuity was affected. RESULTS: Seventeen patients were included in this study. Of this, 46% (8/17) had classic or predominantly classic CNV and 53% (9/17) had occult or minimally classic CNV. Active treatment with intravitreal anti-VEGF injections was required in 35% (6/17). Visual acuity improved in three eyes by 2-4 Snellen lines, remained stable in one eye and worsened in two eyes by 2 Snellen lines. CNV partially regressed in five cases. In the observation group (65%, 11/17), visual acuity did not change during follow-up period. Outer retinal tubulation was found in 18% (3/17). CONCLUSIONS: Anti-VEGF treatment is effective in the management of vision threatening CNV secondary to a choroidal naevus. Functional or anatomical improvement was obtained in 66% of treated eyes. Outer retinal tubulation, noted in 18%, showed the clinical importance of this sign in determining continuation of anti-VEGF treatment.

Reduction of polarization-induced artifacts in grating-based spectrometers.

An optical device that converts unpolarized light into a single polarization state is described. The device is based on a polarizing beam splitter that separates the two polarization directions. The beam splitter is combined with two pairs of equilateral prisms that are used to collimate the two beams in terms of both propagation and polarization directions. When it is used in combination with a blazed diffraction grating, this device is shown to effectively remove the polarization dependence of the first-order diffracted power. The device has an insertion loss of approximately 14% for purely s-polarized light. However, for unpolarized light incident upon the two gratings studied here, the increased throughput of the p-polarized component leads to an average relative gain in overall efficiency of 13%-19%, depending on the grating. In collimating the two polarization directions, the device may cause a reduction in spectral resolution for a rectangular entrance slit. As a result, the device is more likely to find use in spectrometers that have a circular aperture, such as that provided by an optical fiber.

Visual perception during phacoemulsification cataract surgery under topical and regional anaesthesia.

PURPOSE: To compare the subjective visual experiences of patients during phacoemulsification and intraocular lens (IOL) implantation using regional and topical anaesthesia. DESIGN: A prospective, cohort, questionnaire-based study. METHODS: The study cohort consisted of 247 patients without pre-existing ocular pathology who underwent routine phacoemulsification and IOL implantation. The mean age of the subjects was 75.4 +/- 9.4 years and 34.5% of them had a history of cataract surgery. Three different methods of local anaesthesia were used: 66 (26.7%) of the patients were given topical anaesthesia (TA); 74 (30.0%) were given sub-Tenon's anaesthesia (SA), and 107(43.3%) were given peribulbar anaesthesia (PA). The patients were interviewed immediately after surgery by theatre staff using a standardized questionnaire that investigated their intraoperative visual experiences. RESULTS: There was no significant difference between the three methods of anaesthesia regarding light perception during the surgery. However, patients undergoing surgery under TA experienced brighter light intensity levels (78.3%) than those given SA (50.0%) and PA (55.7%) (p = 0.02). A total of 69.6% of subjects who received TA reported visual perception of colours during surgery, as opposed to 56.8% of SA recipients and 49.0% of PA recipients (p = 0.02). In addition, patients under TA were more aware of surgical instruments (26.1%) than those under SA (10.8%) and PA (15.9%) (p = 0.08). The vast majority of patients in all three groups found the visual experience to be non-frightening. There were no associations between intraoperative visual impression and age or sex. Although not statistically significant (p = 0.06), prior cataract surgery appeared to alleviate some of the anxiety associated with the visual experience. CONCLUSION: Patients undergoing regional and topical anaesthesia experience a wide variety of visual sensations during surgery. The differences in visual impressions between the groups may reflect the varying degrees of optic nerve blockade that result from the different anaesthetics.