Search

Analyzing the concentration of ions in aqueous solutions in real-time plays an important role in the fields of chemistry and biology. Traditional methods for measuring ion concentrations, such as concentration analysis by measuring electrical conductivity, inductively coupled plasma mass spectrometry, and ion chromatography, have been used in many research fields. However, these methods are limited in determining ion concentrations instantaneously. Fourier-transform infrared-attenuated total reflectance (ATR-FTIR) spectroscopy provides a new approach for determining ion concentrations in aqueous solutions. This allows for fast analysis without pretreatment and is scalable for real-time measurements. In this study, we present a method for measuring ion concentrations by examining ion-water interactions in the O-H stretching band of aqueous solutions using ATR-FTIR spectroscopy. Five aqueous solutions, namely LiCl + HCl, LiOH + HCl, LiOH, Li 3 PO 4 , and NaCl were used in the experiments and prepared at concentrations between 0.5-2 M. The ion concentrations in the prepared aqueous solutions were measured using ATR-FTIR spectroscopy. We observed that the difference in absorbance increased and decreased linearly with changes in concentration. The concentration of ions in the aqueous solution could be measured by validating the designed linear regression analysis function model. In this study, we proposed five linear regression analysis function models, all of which showed high coefficients of determination above 0.9, with the highest coefficient of determination reaching 0.9969. These results show that ATR-FTIR spectroscopy has the potential to be applied as a rapid and simple concentration analysis system., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (This journal is © The Royal Society of Chemistry.)

Efficient pathogen enrichment and nucleic acid isolation are critical for accurate and sensitive diagnosis of infectious diseases, especially those with low pathogen levels. Our study introduces a biporous silica nanofilms-embedded sample preparation chip for pathogen and nucleic acid enrichment/isolation. This chip features unique biporous nanostructures comprising large and small pore layers. Computational simulations confirm that these nanostructures enhance the surface area and promote the formation of nanovortex, resulting in improved capture efficiency. Notably, the chip demonstrates a 100-fold lower limit of detection compared to conventional methods used for nucleic acid detection. Clinical validations using patient samples corroborate the superior sensitivity of the chip when combined with the luminescence resonance energy transfer assay. The enhanced sample preparation efficiency of the chip, along with the facile and straightforward synthesis of the biporous nanostructures, offers a promising solution for polymer chain reaction-free detection of nucleic acids., (© 2024. The Author(s).)

When a low-viscosity fluid displaces into a higher-viscosity fluid, the liquid-liquid interface becomes unstable causing finger-like patterns. This viscous fingering instability has been widely observed in nature and engineering systems with two adjoined fluids. Here, we demonstrate a hitherto-unrealizable viscous fingering in a single fluid-solid interface. In a single polyelectrolyte fluid on a charge selective surface, selective ion rejection through the surface initiates i) stepwise ion concentration and viscosity gradient boundaries in the fluid and ii) electroconvective vortices on the surface. As the vortices grow, the viscosity gradient boundary pushes away from the surface, resulting viscous fingering. Comparable to conventional one with two fluids, i) a viscosity ratio ([Formula: see text]) governs the onset of this electroconvective viscous fingering, and ii) the boundary properties (finger velocity and rheological effects) - represented by [Formula: see text], electric Rayleigh ([Formula: see text]), Schmidt ([Formula: see text]), and Deborah ([Formula: see text]) numbers - determine finger shapes (straight v.s. ramified, the onset length of fingering, and relative finger width). With controllable onset and shape, the mechanism of electroconvective viscous fingering offers new possibilities for manipulating ion transport and dendritic instability in electrochemical systems., (© 2023. The Author(s).)

Sensory neurons generate spike patterns upon receiving external stimuli and encode key information to the spike patterns, enabling energy-efficient external information processing. Herein, we report an epifluidic electronic patch with spiking sweat clearance using a sensor containing a vertical sweat-collecting channel for event-driven, energy-efficient, long-term wireless monitoring of epidermal perspiration dynamics. Our sweat sensor contains nanomesh electrodes on its inner wall of the channel and unique sweat-clearing structures. During perspiration, repeated filling and abrupt emptying of the vertical sweat-collecting channel generate electrical spike patterns with the sweat rate and ionic conductivity proportional to the spike frequency and amplitude over a wide dynamic range and long time (> 8 h). With such 'spiking' sweat clearance and corresponding electronic spike patterns, the epifluidic wireless patch successfully decodes epidermal perspiration dynamics in an event-driven manner at different skin locations during exercise, consuming less than 0.6% of the energy required for continuous data transmission. Our patch could integrate various on-skin sensors and emerging edge computing technologies for energy-efficient, intelligent digital healthcare., (© 2022. The Author(s).)

Major changes in climate resulting in mass migrations have unique dermatologic implications for global vulnerable populations. Dermatologic manifestations commonly accompany the infectious and communicable diseases that proliferate in the settings of confinement, crowding, and limited sanitation associated with mass migration. Ectoparasitic infestations abound in refugee camps, and poor nutrition, hygiene, and compromised immunity put refugees at an increased risk for more dangerous infectious diseases carried by these ectoparasites. Climate change also profoundly affects the worldwide distribution of various vector-borne illnesses, thereby leading to the emergence of various communicable diseases in previously nonendemic areas. Natural disasters not only disrupt important lifesaving treatments, but also challenge various infectious disease control measures that are critical in preventing rapid transmission of highly infectious diseases. This article reviews the infectious diseases commonly found in these scenarios and provides an in-depth discussion of important implications for the dermatologist., (© 2020 Published by Elsevier Inc. on behalf of Women's Dermatologic Society.)

Background: There is a dearth in our understanding of the factors that are predictive of successful spinal cord stimulator (SCS) trials and eventual conversion to permanent implants. Knowledge of these factors is important for appropriate patient selection and treatment optimization., Objectives: Although previous studies have explored factors predictive of trial success, few have examined the role of waveform in trial outcomes. This study sought to establish the relationship of neuraxial waveform and related measures to trial outcomes., Study Design: This study used a retrospective chart review design., Methods: Data were retrospectively collected on 174 patients undergoing SCS trials upon institutional review board approval of the study protocol. Indications for SCS were: complex regional pain syndrome, failed back surgery syndrome with radicular symptoms, peripheral neuropathy, and axial low back pain. Descriptive statistics and logistic regression analyses were used to assess the association of demographic and clinical variables with SCS trial outcomes., Results: The study population comprised 56% women, had a median age of 55 (interquartile range [IQR], 44-64), and 32 of 174 (18%) patients failed SCS trials. Individuals with successful trials (>= 50% pain relief) were significantly younger and had a median age of 54 years (IQR, 42-60) compared to those who failed SCS trials (median age 66 years; IQR, 50-76; P = .005). Adjusting for age, gender, number of leads, pain category, and diagnoses: surgical history (odds ratio [OR] = 4.4; 95% confidence interval [CI], 1.3-15.8) and paresthesia-based tonic-stimulation (OR = 10.3; 95% CI, 1.7-62.0), but not burst or high frequency, were significantly associated with successful trials. Of note, the number of leads (whether dual or single), pain duration, characteristics, and category (nociceptive vs neuropathic) were not significant factors. An interaction between surgical spine history and lower extremity pain was significantly associated with a positive trial (P = .005)., Limitations: This study was limited by its retrospective nature and focus on a patient population at a single major academic medical center., Conclusions: Paresthesia-based tonic stimulation, age, and surgical history have significant effects on SCS trials. Prospective and randomized controlled studies may provide deeper insights regarding impact on costs and overall outcomes.IRB Approval #: 2018P002216., Key Words: Pain duration, pain location, spinal cord stimulator trial, stimulator waveform, surgical history.

Background: Despite improvements in cancer management, most pancreatic cancers are still diagnosed at an advanced stage. We have recently identified promoter DNA methylation of the genes ADAMTS1 and BNC1 as potential blood biomarkers of pancreas cancer. In this study, we validate this biomarker panel in peripheral cell-free tumor DNA of patients with pancreatic cancer., Results: Sensitivity and specificity for each gene are as follows: ADAMTS1 87.2% and 95.8% (AUC = 0.91; 95% CI 0.71-0.86) and BNC1 64.1% and 93.7% (AUC = 0.79; 95% CI 0.63-0.78). When using methylation of either gene as a combination panel, sensitivity increases to 97.3% and specificity to 91.6% (AUC = 0.95; 95% CI 0.77-0.90). Adding pre-operative CA 19-9 values to the combined two-gene methylation panel did not improve sensitivity. Methylation of ADAMTS1 was found to be positive in 87.5% (7/8) of stage I, 77.8% (7/9) of stage IIA, and 90% (18/20) of stage IIB disease. Similarly, BNC1 was positive in 62.5% (5/8) of stage I patients, 55.6% (5/9) of stage IIA, and 65% (13/20) of patients with stage IIB disease. The two-gene panel (ADAMTS1 and/or BNC1) was positive in 100% (8/8) of stage I, 88.9% (8/9) of stage IIA, and 100% (20/20) of stage IIB disease. The sensitivity and specificity of the two-gene panel for localized pancreatic cancer (stages I and II), where the cancer is eligible for surgical resection with curative potential, was 94.8% and 91.6% respectively. Additionally, the two-gene panel exhibited an AUC of 0.95 (95% CI 0.90-0.98) compared to 57.1% for CA 19-9 alone., Conclusion: The methylation status of ADAMTS1 and BNC1 in cfDNA shows promise for detecting pancreatic cancer during the early stages when curative resection of the tumor is still possible. This minimally invasive blood-based biomarker panel could be used as a promising tool for diagnosis and screening in a select subset of high-risk populations.

There is an increasing need for the desalination of high concentration brine (>TDS 35,000 ppm) efficiently and economically, either for the treatment of produced water from shale gas/oil development, or minimizing the environmental impact of brine from existing desalination plants. Yet, reverse osmosis (RO), which is the most widely used for desalination currently, is not practical for brine desalination. This paper demonstrates technical and economic feasibility of ICP (Ion Concentration Polarization) electrical desalination for the high saline water treatment, by adopting multi-stage operation with better energy efficiency. Optimized multi-staging configurations, dependent on the brine salinity values, can be designed based on experimental and numerical analysis. Such an optimization aims at achieving not just the energy efficiency but also (membrane) area efficiency, lowering the true cost of brine treatment. ICP electrical desalination is shown here to treat brine salinity up to 100,000 ppm of Total Dissolved Solids (TDS) with flexible salt rejection rate up to 70% which is promising in a various application treating brine waste. We also demonstrate that ICP desalination has advantage of removing both salts and diverse suspended solids simultaneously, and less susceptibility to membrane fouling/scaling, which is a significant challenge in the membrane processes.

Chloride ion, the majority salt in nature, is ∼52% faster than sodium ion (DNa+ = 1.33, DCl- = 2.03[10(-9)m(2)s(-1)]). Yet, current electrochemical desalination technologies (e.g. electrodialysis) rely on bipolar ion conduction, removing one pair of the cation and the anion simultaneously. Here, we demonstrate that novel ion concentration polarization desalination can enhance salt removal under a given current by implementing unipolar ion conduction: conducting only cations (or anions) with the unipolar ion exchange membrane stack. Combining theoretical analysis, experiment, and numerical modeling, we elucidate that this enhanced salt removal can shift current utilization (ratio between desalted ions and ions conducted through electrodes) and corresponding energy efficiency by the factor ∼(D- - D+)/(D- + D+). Specifically for desalting NaCl, this enhancement of unipolar cation conduction saves power consumption by ∼50% in overlimiting regime, compared with conventional electrodialysis. Recognizing and utilizing differences between unipolar and bipolar ion conductions have significant implications not only on electromembrane desalination, but also energy harvesting applications (e.g. reverse electrodialysis).

CpG island methylator phenotype (CIMP) has been found in multiple precancerous and cancerous lesions, including colorectal adenomas, colorectal cancers, and duodenal adenocarcinomas. There are no reports in the literature of a relationship between CIMP status and clinicopathologic features of sporadic duodenal adenomas. This study sought to elucidate the role of methylation in duodenal adenomas and correlate it with KRAS and BRAF mutations. CIMP+ (with more than 2 markers methylated) was seen in 33.3% of duodenal adenomas; 61% of these CIMP+ adenomas were CIMP-high (with more than 3 markers methylated). Furthermore, CIMP+ status significantly correlated with older age of patients, larger size and villous type of tumor, coexistent dysplasia and periampullary location. MLH1 methylation was seen in 11.1% of duodenal adenomas and was significantly associated with CIMP+ tumors, while p16 methylation was an infrequent event. KRAS mutations were frequent and seen in 26.3% of adenomas; however, no BRAF mutations were detected. Furthermore, CIMP-high status was associated with larger size and villous type of tumor and race (non-white). These results suggest that CIMP+ duodenal adenomas may have a higher risk for developing malignancy and may require more aggressive management and surveillance.

Purpose: Little information is available on genetic and epigenetic changes in duodenal adenocarcinomas. The purpose was to identify possible subsets of duodenal adenocarcinomas based on microsatellite instability (MSI), DNA methylation, mutations in the KRAS and BRAF genes, clinicopathologic features, and prognosis., Experimental Design: Demographics, tumor characteristics, and survival were available for 99 duodenal adenocarcinoma patients. Testing for KRAS and BRAF mutations, MSI, MLH1 methylation, and CpG island methylator phenotype (CIMP) status was conducted. A Cox proportional hazard model was built to predict survival., Results: CIMP(+) was detected in 27 of 99 (27.3%) duodenal adenocarcinomas and was associated with MSI (P = 0.011) and MLH1 methylation (P < 0.001), but not with KRAS mutations (P = 0.114), as compared with CIMP(-) tumors. No BRAF V600E mutation was detected. Among the CIMP(+) tumors, 15 (55.6%) were CIMP(+)/MLH1-unmethylated (MLH1-U). Kaplan-Meier analysis showed that tumors classified by CIMP, CIMP/MLH1 methylation status, or CIMP/MSI status could predict overall survival (OS; P = 0.047, 0.002, and 0.002, respectively), whereas CIMP/MLH1 methylation status could also predict time-to-recurrence (TTR; P = 0.016). In multivariate analysis, CIMP/MLH1 methylation status showed a significant prognostic value in both OS (P < 0.001) and TTR (P = 0.023). Patients with CIMP(+)/MLH1-U tumors had the worst OS and TTR., Conclusions: Our results showed existence of CIMP in duodenal adenocarcinomas. The combination of CIMP(+)/MLH1-U seems to be independently associated with poor prognosis in patients with duodenal adenocarcinomas. This study also suggests that BRAF mutations are not involved in duodenal tumorigenesis, MSI, or CIMP development., (©2012 AACR.)

Direct extension of a glioblastoma through the dura at the skull base is an uncommon occurrence. We report an unusual case of recurrent glioblastoma that spread transdurally through the foramen ovale and presented primarily as a masticator space mass. There was mandibular denervation and a relative paucity of intracranial disease.

Using a large consortium of undergraduate students in an organized program at the University of California, Los Angeles (UCLA), we have undertaken a functional genomic screen in the Drosophila eye. In addition to the educational value of discovery-based learning, this article presents the first comprehensive genomewide analysis of essential genes involved in eye development. The data reveal the surprising result that the X chromosome has almost twice the frequency of essential genes involved in eye development as that found on the autosomes.

Cerebral angiography revealed that hypoplasia of the A1 portion of the anterior cerebral artery is more frequent in patients with aneurysms of the anterior communicating artery than in those with aneurysms of other intracranial arteries. As for the hypoplasia of the A1, the angiographic findings corresponded to the surgical findings in 86.9% of all the patients. In patients with anterior communicating artery aneurysms, the incidence of hypoplasia of the A1 portion was about 3 times higher on the right side than on the left side.

In spite of many reports of arrest reaction in animals, there are very few reports in man. During a therapeutic stereotactic operation we observed peculiar phenomena caused by electrical stimulation to the deep structure of the cerebrum. The electrical stimulation caused an interruption of counting and other motor actions, which could be resumed following release of stimuli. In almost all cases psychic confusion of memory disturbances were not observed. The head of the caudate nucleus and its adjacent white matter cause arrest reaction with the lowest threshold of 5 V; on the other hand, substantia medullaris lobi frontalis, radiatio corporis callosi and nucl. reticularis oralis of the thalamus caused arrest reaction with the highest threshold of 10--15 V. The arrest reaction that we observed is thought to be due to a direct effect on the head of the caudate nucleus, not due to secondary effects on the internal capsule and the motor fiber in the vicinity of the caudate nucleus. However, the possibility that the current spread to the motor fiber cannot be definitely ruled out.

Of 274 operated cases of cerebral aneurysm, temporary occlusion of the cerebral arteries was used in 215 cases (79%). Of the 215 cases, 177 (82%) showed no sequelae. The maximum safe time limit for temporary occlusion at the bilateral A1 portion of the anterior cerebral arteries was 48.5 min at 26 degrees C, 47 min at 27 degrees C, and 42 min at 28 degrees C; at the M1 portion of the middle cerebral arteries, it was 30 min at 26 degrees C, 35 min at 27 degrees C, 36 min at 27.5 degrees C, 40 min at 30 degrees C and 19 min at normothermia; and at the dominant A1 portion, in cases of hypoplasia at the contralateral A1 portion, it was 82 min at 26 degrees C, 86 min at 27.5 degrees C, and 63 min at 28 degrees C. Consequently, when performing direct surgery on aneurysms of the anterior communicating artery, unilateral clamping of the A1 portion prevents rupture during surgery and has the advantage of prolonging the occlusion time. Neurological sequelae may have been caused by the temporary occlusion of the cerebral artery in one case, and by the temporary occlusion or the surgical operation in six cases. Of the 22 fatal cases, only one was thought to be due to the temporary occlusion of the cerebral artery. Intermittent release of the clamping for 5 to 10 min is considered to be effective in prolonging the safe time limit of temporary clamping of the cerebral arteries in surgery of cerebral aneurysm under moderate hypothermia.

The incidence of hypertension in past history was investigated in 811 cases of cerebral aneurysm. These cases were compiled from 1,000 cases of saccular aneurysm in which direct surgical operations for aneurysm were performed at our clinic during the period from June 1961 to September 1975. Of the 811 cases, 365 (45%) had hypertension in their past history; 185 (42.7%) out of 433 males and 180 (47.6%) out of 378 females. In the 5th decade of age, the incidence was significantly higher in the females than in the males, but no difference by sex was noted in other age groups. In the males from the 3rd to the 7th decade, the number of hypertensives increased significantly with advancing age, whereas in the females a significant difference was observed only between the 4th and 7th decades, the latter including more hypertensives. The incidence of hypertensives in the aneurysm cases was compared with that in the Japanese population reported by Sasaki. This comparison revealed that in both sexes between the 4th and 6th decades, the incidence was significantly higher in the former, whereas no significant difference was noted between the two in the 7th decade. As to the location of aneurysms, only the multiple aneurysms group had a significantly greater number of hypertensives than single aneurysm group. These results agree with previous reports that cerebral aneurysm may occur more frequently in the hypertensives than in the normotensives.