Sequency encoding single pixel spectroscopy based on Hadamard transform

Single pixel spectroscopy based on Hadamard transform (SPS-HT) has been applied widely because of its capability of wavelength multiplexing and associated advantage in signal-to-noise ratio. In this paper, we propose a sequency encoding single pixel spectroscopy (SESPS) based on two-dimensional (2D) masks for concurrent coding of all Hadamard coefficients instead of one-dimensional (1D) Hadamard masks (only coding one coefficient at a time) widely used in the traditional SPS-HT. Moreover, each Hadamard coefficient is coded along the time dimension with a different sequency value such that the alternating current (AC) measurements of the time-domain signal can be used to reconstruct all Hadamard coefficients simultaneously, which reduces the influence of noise and dramatically speeds up data acquisition. We demonstrate that the SESPS with 32 spectral channels can accelerate spectral measurements from white light sources and fluorescence particles by around 14 times and 70 times, respectively, compared to measurements using a commercial spectrometer when the relative root mean square error (RMSE) is around 3% or smaller. The acceleration factors can be boosted by an extra 4 times when only eight spectral channels are used to achieve a compression ratio of 4:1, in which the relative RMSEs change only marginally. Compared to our previous SPS-HT, this new scheme can increase the speed by three orders of magnitude. This technique is expected to be useful in applications requiring high-speed spectral measurements such as the spectral flow cytometry and on-site medical diagnosis using fluorescence or Raman spectroscopy.

Implementing 3HP vs. IPT as TB preventive treatment in Pakistan

BACKGROUND: We assessed treatment uptake and completion for 6 months of isoniazid (6H) and 3 months of isoniazid plus rifapentine weekly (3HP) in a programmatic setting in Pakistan.METHODS: All household contacts were clinically evaluated to rule out TB disease. 6H was used for TB preventive treatment (TPT) from October 2016 to April 2017; from May to September 2017, 3HP was used for contacts aged ≥2 years. We compared clinical evaluation, TPT uptake and completion rates between contacts aged ≥2 years in the 6H period and in the 3HP period.RESULTS: We identified 3,442 contacts for the 6H regimen. After clinical evaluation, 744/1,036 (72%) started treatment, while 46% completed treatment. In contrast, 3,722 contacts were identified for 3HP. After clinical evaluation, 990/1,366 (72%) started treatment, while 67% completed treatment. Uptake of TPT did not differ significantly between the 6H and 3HP groups (OR 1.03, 95%CI 0.86-1.24). However, people who initiated 3HP had 2.3 times greater odds (95% CI 1.9-2.8) of completing treatment than those who initiated 6H after adjusting for age and sex.CONCLUSION: In programmatic settings in a high-burden country, household contacts of all ages were more likely to complete TPT with shorter weekly regimens, although treatment uptake rate for the two regimens was similar.

Melatonin versus chloral hydrate as the sedating agent in performing electroencephalogram in paediatric patients

Electroencephalography (EEG) is a valuable tool in the diagnosis of epilepsy. The attainment of a high quality EEG requires patient's co-operation which is particularly difficult in children. Chloral hydrate has been used as a sedating agent in EEGs but it has potential serious adverse effects and anti-epileptic activity. Melatonin is used increasingly in different investigations as a safe alternative. Our study is to compare their effectiveness as sedating agents in performing EEGs and the detection rate of abnormal EEGs. This is a retrospective study performed in a regional hospital in Hong Kong. One hundred and ninety two EEG studies were included from December 2010 to July 2014. One hundred and two children were given chloral hydrate (50 mg/Kg) in the first half of the period and 90 children were given melatonin (3 mg for =< 5 years or 6 mg for >= 5 year) in the later half. The two groups are compared with Pearson's Chi-squared test with Yates’ continuity correction. The successful rate in sedation was similar between the two groups while the pick up rate of abnormal EEGs was 52.56% in the melatonin group and 21.57% in the chloral hydrate group (p < 0.05). Subgroup analysis among patients with epilepsy or mental retardation and intellectual disability shared same findings with higher detection rate of abnormal EEGs in the melatonin group. No side effect was documented in the study. Compare with chloral hydrate, melatonin is a safe and effective alternative and probably has less interference with the electrographic activity.

Hollow agarose microneedle with silver coating for intradermal surface-enhanced Raman measurements: a skin-mimicking phantom study

Human intradermal components contain important clinical information beneficial to the field of immunology and disease diagnosis. Although microneedles have shown great potential to act as probes to break the human skin barrier for the minimally invasive measurement of intradermal components, metal microneedles that include stainless steel could cause the following problems: (1) sharp waste production, and (2) contamination due to reuse of microneedles especially in developing regions. In this study, we fabricate agarose microneedles coated with a layer of silver (Ag) and demonstrate their use as a probe for the realization of intradermal surface enhanced Raman scattering measurements in a set of skin-mimicking phantoms. The Ag-coated agarose microneedle quantifies a range of glucose concentrations from 5 to 150 mM inside the skin phantoms with a root-mean-square error of 5.1 mM within 10 s. The needle is found enlarged by 53.9% after another 6 min inside the phantom. The shape-changing capability of this agarose microneedle ensures that there use of these microneedles is impossible, thus avoiding sharp waste production and preventing needle contamination,which shows the great potential for safe and effective needle-based measurements.

Treatment for a eumycetoma infection caused by Aspergillus in an immunocompromised host: a case report

Eumycetoma is a chronic infection of the skin and subcutaneous tissue caused by filamentous fungi, which usually occurs in tropical or subtropical countries. We report a case of an immunocompromised patient presenting with presumed eumycetoma in the United States and his subsequent treatment with voriconazole. The use of voriconazole and liposomal amphotericin B halted the progression and allowed gradual resolution of the infection. The patient will require close monitoring and long-term therapy with voriconazole to obtain a clinical cure. Voriconazole and liposomal amphotericin B are potential initial treatment options, with long-term voriconazole maintenance therapy, for an Aspergillus-induced eumycetoma.

Towards in vivo intradermal surface enhanced Raman scattering (SERS) measurements: silver coated microneedle based SERS probe

We propose a microneedle coated with silver (Ag) to detect analytes at low concentrations positioned at a depth of more than 700 μm below the surface of a skin phantom with absorbers and scatterers for mimicking the intradermal surface-enhanced Raman scattering (SERS) measurements. The Ag layer in the Ag-coated microneedle-based probe is found to be the key to the effective detection of analytes buried inside the aforesaid phantom. Glucose concentrations ranging from 5 to 150 mM inside phantoms can be estimated with a root mean square error (RMSE) of 3.3 mM. This work shows the potential of using microneedles for simple in vivo intradermal SERS measurements of analytes with clinical relevance.

Optimization of Fe3O4@Ag nanoshells in magnetic field-enriched surface-enhanced resonance Raman scattering for malaria diagnosis

The great potential of magnetic field enriched surface enhanced resonance Raman spectroscopy (SERRS) for early malaria diagnosis has been demonstrated previously. This technique is able to detect β-hematin, which is equivalent to a malaria biomarker (hemozoin) in Raman features, at a concentration of 5 nM. In this study, we present the optimization of nanoparticles used in the magnetic field enriched SERRS by tuning the core size and shell thickness of nanoparticles with an iron oxide core and a silver shell (Fe3O4@Ag). The discrete dipole approximation (DDA) model was introduced to investigate the localized electromagnetic field distributions and extinction efficiencies of the aggregate of Fe3O4@Ag and β-hematin, in correlation with their magnetic field enriched SERRS performance. We find that the optimal core-shell size of Fe3O4@Ag leading to the effective aggregation of Fe3O4@Ag and β-hematin under an external magnetic field with superior extinction efficiencies is the key to realize highly augmented Raman signals in this strategy. Furthermore, it is noted that the optimized result differs from the case without the external magnetic field to that with the external magnetic field. Therefore, this work demonstrates experimentally and theoretically the potential of tuning the core-shell Fe3O4@Ag for achieving the efficient magnetic field-enriched SERRS detection of β-hematin for early malaria diagnosis.

Recovery of Raman spectra with low signal-to-noise ratio using Wiener estimation

Raman spectroscopy is a powerful non-destructive technique for qualitatively and quantitatively characterizing materials. However, noise often obscures interesting Raman peaks due to the inherently weak Raman signal, especially in biological samples. In this study, we develop a method based on spectral reconstruction to recover Raman spectra with low signal-to-noise ratio (SNR). The synthesis of narrow-band measurements from low-SNR Raman spectra eliminates the effect of noise by integrating the Raman signal along the wavenumber dimension, which is followed by spectral reconstruction based on Wiener estimation to recover the Raman spectrum with high spectral resolution. Non-negative principal components based filters are used in the synthesis to ensure that most variance contained in the original Raman measurements are retained. A total of 25 agar phantoms and 20 bacteria samples were measured and data were used to validate our method. Four commonly used de-noising methods in Raman spectroscopy, i.e. Savitzky-Golay (SG) algorithm, finite impulse response (FIR) filtration, wavelet transform and factor analysis, were also evaluated on the same set of data in addition to the proposed method for comparison. The proposed method showed the superior accuracy in the recovery of Raman spectra from measurements with extremely low SNR, compared with the four commonly used de-noising methods.

Patterns of adherence to NICE glaucoma guidance in two different service delivery models

PURPOSE

To assess adherence patterns to the UK National Institute of Health and Clinical Excellence (NICE) guidelines on glaucoma management (2009) in a tertiary referral centre shared care setting and in a district general hospital (DGH) setting.

METHOD

We performed a retrospective case note analysis of 200 patients from two centres between January and June 2010. The two centres involved were a consultant-guided teaching hospital optometry-led shared care setting (setting 1) and a consultant-led DGH clinic setting (setting 2). The main outcome measures were compliance with eight of the main NICE guidelines on glaucoma diagnosis and management (2009).

RESULTS

Both centres showed good adherence to the guidelines regarding the choice of initial treatment (96% vs 100%, settings 1 and 2, respectively) and arranging appropriate monitoring intervals (92% vs 86%). However, significant differences were seen when assessing whether an optic disc image was obtained at the initial visit (74% vs 10%), whether an appropriate initial assessment was performed (96% vs 58%), whether patients' review interval complied with the NICE guidance regardless of hospital cancellations (92% vs 66%), and whether concordance with medication was checked (88% vs 24%) (settings 1 and 2, respectively, P<0.01-Fisher's exact test).

CONCLUSION

Our study provides evidence to suggest that a hospital-based shared care service with trained optometrists using assessment sheets compares favourably to non-specialist glaucoma care delivered by ophthalmologists.

Magnetic field enriched surface enhanced resonance Raman spectroscopy for early malaria diagnosis

Hemozoin is a by-product of malaria infection in erythrocytes, which has been explored as a biomarker for early malaria diagnosis. We report magnetic field-enriched surface-enhanced resonance Raman spectroscopy (SERRS) of β-hematin crystals, which are the equivalent of hemozoin biocrystals in spectroscopic features, by using magnetic nanoparticles with iron oxide core and silver shell (Fe(3)O(4)@Ag). The external magnetic field enriches β-hematin crystals and enhances the binding between β-hematin crystals and magnetic nanoparticles, which provides further improvement in SERRS signals. The magnetic field-enriched SERRS signal of β-hematin crystals shows approximately five orders of magnitude enhancement in the resonance Raman signal, in comparison to about three orders of magnitude improvement in the SERRS signal without the influence of magnetic field. The improvement has led to a β-hematin detection limit at a concentration of 5 nM (roughly equivalent to 30 parasites/μl at the early stages of malaria infection), which demonstrates the potential of magnetic field-enriched SERRS technique in early malaria diagnosis.

Low-level detection of anti-cancer drug in blood plasma using microwave-treated gold-polystyrene beads as surface-enhanced Raman scattering substrates

We report on a low-level detection of anti-cancer drug (paclitaxel) in blood plasma using microwave-treated gold (Au) film-polystyrene (PS) beads as surface-enhanced Raman scattering (SERS) substrates. SERS spectra of paclitaxel can be acquired within 10s at a concentration of 1×10(-8) M in blood plasma adsorbed on the modified Au-PS SERS substrates. The concentrations of paclitaxel ranging from 1.0×10(-8) to 1.0×10(-7) M in blood plasma can be well estimated with an accuracy of ∼3.8×10(-9) M using SERS technique. This work shows the promise of applying microwave-modified Au-PS as SERS substrates for rapid and accurate monitoring of the anti-cancer drug in blood plasma for immediate treatment decisions during cancer therapy.

Si-based light-emitting structure synthesized with low-energy ion implantation at a low dosage

In this work, Si-based light-emitting structures were synthesized by Si+ implantation into 30 nm thermally grown SiO2 films with a low dosage (< or =1 x 10(16)/cm2). The emission band of electroluminescence (EL) extends from 300 nm to 700 nm with a peak at around 500 nm. The onset voltage for the EL is around 5 V for the 8 keV implanted sample which is low enough for many device applications. The light emission mechanism is studied in this work. It is believed that the defects in the Si+ implanted SiO2 films are the luminescent centers responsible for the EL. In addition, it is found the light emission intensity can be affected by charge trapping in nc-Si.

Improving surface-enhanced Raman scattering effect using gold-coated hierarchical polystyrene bead substrates modified with postgrowth microwave treatment

We report a novel postgrowth microwave heating implementation by selectively modifying hierarchical polystyrene (PS) bead substrates coated with gold (Au) films to effectively improve the surface-enhanced Raman scattering (SERS) effect on the analytes. The SERS signal of probe molecule rhodamine 6G (Rh 6G) on the microwave-treated Au-PS substrates can be improved by 10-fold, while the detection limit of Rh 6G in concentration can be enhanced by two orders of magnitude compared to the as-growth substrates. The high-quality SERS spectrum of saliva can also be acquired using the modified substrates, demonstrating the potential for the realization of the high-performance SERS substrates for biomedical applications.

Endocapsular iris reconstruction implants for acquired iris defects: a clinical study

PURPOSE

To report the clinical efficacy, safety, and long-term follow-up data on the use of endocapsular iris reconstruction implants (IRIs) during cataract surgery in patients with acquired iris defects.

METHODS

Single centre, retrospective, noncomparative, interventional case series. Five eyes of four patients with acquired iris defects and visually significant cataracts underwent clear cornea phacoemulsification and intraocular lens (IOL) implantation combined with insertion of endocapsular IRI. Data on the best-corrected visual acuity (BCVA), degree of preoperative and postoperative glare, photophobia, surgical complications, and long-term implant stability were analysed.

RESULTS

In all patients, IRI were successfully placed within the capsular bag during cataract surgery. There were no intraoperative or postoperative complications. Mean follow-up period was 29 months (range, 16-42). BCVA, subjective glare, and photophobia improved in all five eyes. Desired anatomic results were achieved in all of them.

CONCLUSIONS

In patients with acquired iris defects, implantation of endocapsular IRI during cataract surgery appears to be a safe and effective procedure. At a mean time gate of 29 months, both IOLs and IRI appeared to remain stable within the capsular bag.

Cost-effectiveness comparison of current proton-pump inhibitors to treat gastro-oesophageal reflux disease in the UK

OBJECTIVE

Gastro-oesophageal reflux disease (GORD) is a recurring condition with many patients requiring long-term maintenance therapy. Therefore initial choice of treatment has long-term cost implications. The aim was to compare the costs and effectiveness of treatment of GORD the (unconfirmed by endoscopy) with seven proton pump inhibitors (PPIs: esomeprazole, lansoprazole (capsules and oro-dispersible tablets), omeprazole (generic and branded), pantoprazole and rabeprazole), over one year.

DESIGN AND METHODS

A treatment model was developed of 13 interconnected Markov models incorporating acute treatment of symptoms, long-term therapy and subsequent decisions to undertake endoscopy to confirm diagnosis. Patients were allowed to stop treatment or to receive maintenance treatment either continuously or on-demand depending on response to therapy. Long-term dosing schedule (high dose or step-down dose) was based on current market data. Efficacy of treatments was based on clinical trials and follow-up studies, while resource use patterns were determined by a panel of physicians.

MAIN OUTCOME MEASURES

The model predicts total expected annual costs, number of symptom-free days and quality-adjusted life-years (QALY).

RESULTS

Generic omeprazole and rabeprazole dominated (i.e. cost less and resulted in more symptom-free days and higher QALY gains) the other PPIs. Rabeprazole had a favourable cost-effectiveness ratio of 3.42 pounds per symptom-free day and 8308 pounds/quality-adjusted life-year gained when compared with generic omeprazole. Rabeprazole remained cost-effective independent of choice of maintenance treatment (i.e. proportion of patients remaining on continuous treatment versus on-demand treatment).

CONCLUSIONS

Economic models provide a useful framework to evaluate PPIs in realistic clinical scenarios. Our findings show that rabeprazole is cost-effective for the treatment of GORD.

Oxandrolone in trauma patients

STUDY OBJECTIVE

To determine the effect of oxandrolone administration on nutritional and clinical outcomes after multiple trauma.

DESIGN

Prospective, randomized, double-blind, placebo-controlled study.

SETTING

Level 1 trauma center in a university teaching hospital.

PATIENTS

Sixty-two patients requiring enteral nutrition, 60 of whom completed the study.

INTERVENTION

Patients were randomized to receive either oxandrolone 10 mg or placebo twice/day for a maximum of 28 days.

MEASUREMENTS AND MAIN RESULTS

Total urinary nitrogen, prealbumin, nitrogen balance, total body water, and body cell mass were measured on day 1 of enteral nutrition and then at day 7, day 10, and study exit. Patients were assessed daily for metabolic and infectious complications. The two groups were similar for demographics and dosage of enteral nutrition. Measurement of total urinary nitrogen at study entry showed both groups to be highly catabolic (oxandrolone 17.2 +/- 4.9, placebo 19.1 +/- 10.8 g/day, NS). On days 7 and 10, total urinary nitrogen increased in both groups; however, there was no significant difference between groups. Nitrogen balance was negative throughout the study in each group. Body cell mass decreased slightly in both groups over the study period. Prealbumin serum concentrations increased significantly in both groups at day 10 and study exit compared with study entry. The groups did not differ significantly for length of hospital stay (oxandrolone 30.8 +/- 17.9, placebo 27.0 +/- 25.7 days), length of intensive care unit stay (oxandrolone 17.1 +/- 7.8, placebo 15.5 +/- 9.7 days), and frequency of pneumonia or sepsis (oxandrolone 48, placebo 43 episodes).

CONCLUSION

Oxandrolone 20 mg/day does not have obvious benefit in nutritional and clinical outcomes during the first month after multiple trauma.

Utilitarian tradeoff between population growth and income growth

"This paper extends the comparison of classical and average utilitarianism from a static to a dynamic and endogenously growing economy. Using a stylised endogenous growth framework, it confirms that the Benthamite population growth rate exceeds the Millian growth rate. In terms of the rate of growth of per capita income, the reverse is true. Having the standard of living often increasing under the Benthamite criterion, our results thereby depart significantly from 'the repugnant conclusion' levelled against classical utilitarianism."

The first example of anti-Gya detected in Hong Kong

The incidence of anti-Gya is known to be extremely rare, and only a few examples have been reported in Japanese persons and in Caucasians. This case history reports the first example of anti-Gya detected in a Chinese person. The propositus is an 83-year-old male patient whose anti-Gya was revealed because of incompatibility of all units of blood tested by a saline indirect antiglobulin test (SIAT). Although the antibody had a titer of 512 by SIAT, 10 units of Gy(a+) red cells were transfused without any adverse effect.

Chemotactic peptides modulate adherence of human polymorphonuclear leukocytes to monolayers of cultured endothelial cells

We have used a new centrifugation assay to examine the effects of highly purified human C5a and C5a des Arg, as well as effects of N-formyl-methionyl-leucyl-phenylalanine (FMLP), on both the extent and strength of human polymorphonuclear leukocyte (PMN) adherence to monolayers of cultured human umbilical vein endothelial cells. At concentrations that were chemotactic for PMN, C5a (0.1 nM), C5a des Arg (5.0 nM), and FMLP (1.0 nM) significantly reduced the percentage of PMN that adhered to endothelial monolayers. Adherence also was reduced by C5a des Arg that was generated by incubating (37 degrees C, 30 min) fresh human serum with either zymosan or purified C5a. High concentrations of C5a (greater than 1.0 nM) and FMLP (greater than 50 nM) that diminished PMN chemotaxis significantly enhanced the percentage of PMN that adhered tightly to endothelial cells (adherent cells resisted a dislodgment force of 1200 X G). Tight adherence of PMN to endothelial cells also was increased by high concentrations of C5a that were added to human serum in which carboxypeptidase N activity was destroyed by heating (56 degrees C, 30 min), and by C5a that was generated by incubating (37 degrees C, 30 min) fresh human serum with zymosan in the presence of the carboxypeptidase N inhibitor, epsilon-aminocaproic acid. High concentrations of C5a des Arg (up to 80 nM) neither enhanced adherence of PMN to endothelial cells nor decreased PMN migration. Thus, a reciprocal relation exists between PMN migration and PMN adherence to endothelial cells in response to chemotactic factors. At concentrations that are chemotactic for human PMN, C5-derived peptides and FMLP reduce the adherence of PMN to endothelial monolayers. Only at concentrations that decrease PMN migration do C5a and FMLP augment PMN adherence.

Chemotactic peptides modulate adherence of human polymorphonuclear leukocytes to monolayers of cultured endothelial cells

We have used a new centrifugation assay to examine the effects of highly purified human C5a and C5a des Arg, as well as effects of N-formyl-methionyl-leucyl-phenylalanine (FMLP), on both the extent and strength of human polymorphonuclear leukocyte (PMN) adherence to monolayers of cultured human umbilical vein endothelial cells. At concentrations that were chemotactic for PMN, C5a (0.1 nM), C5a des Arg (5.0 nM), and FMLP (1.0 nM) significantly reduced the percentage of PMN that adhered to endothelial monolayers. Adherence also was reduced by C5a des Arg that was generated by incubating (37 degrees C, 30 min) fresh human serum with either zymosan or purified C5a. High concentrations of C5a (greater than 1.0 nM) and FMLP (greater than 50 nM) that diminished PMN chemotaxis significantly enhanced the percentage of PMN that adhered tightly to endothelial cells (adherent cells resisted a dislodgment force of 1200 X G). Tight adherence of PMN to endothelial cells also was increased by high concentrations of C5a that were added to human serum in which carboxypeptidase N activity was destroyed by heating (56 degrees C, 30 min), and by C5a that was generated by incubating (37 degrees C, 30 min) fresh human serum with zymosan in the presence of the carboxypeptidase N inhibitor, epsilon-aminocaproic acid. High concentrations of C5a des Arg (up to 80 nM) neither enhanced adherence of PMN to endothelial cells nor decreased PMN migration. Thus, a reciprocal relation exists between PMN migration and PMN adherence to endothelial cells in response to chemotactic factors. At concentrations that are chemotactic for human PMN, C5-derived peptides and FMLP reduce the adherence of PMN to endothelial monolayers. Only at concentrations that decrease PMN migration do C5a and FMLP augment PMN adherence.

Adherence of human polymorphonuclear leukocytes to endothelial monolayers: effects of temperature, divalent cations, and chemotactic factors on the strength of adherence measured with a new centrifugation assay

Polymorphonuclear leukocytes (PMNs) adhere to endothelial cells at sites of acute inflammation. To examine this phenomenon in vitro, we have developed a new assay to measure adherence of PMNs to cultured endothelial cells. Human PMNs were labeled with 111indium-oxine and incubated in microtiter wells with monolayers of either human umbilical vein or bovine aortic endothelial cells. Following incubation, the wells were sealed, inverted, and centrifuged at varying speeds. Results are expressed as the percentage of PMNs added initially that remained attached to the monolayers after being subjected to dislodgment forces (ie, relative centrifugal forces) ranging from 1 to 1,200 g. Adherence of PMNs to endothelial monolayers was temperature dependent, dependent on the concentration of extracellular Mg2+ (but not Ca2+), and enhanced significantly by the chemotactic peptides, N-formyl-methionyl-leucyl-phenylalanine (fMLP) and human C5a. It was found that fMLP and C5a not only increased the number of PMNs that adhered to endothelial cells, but also increased the strength of adherence.