BACKGROUND Intracranial blister-like microaneurysms are an extremely rare disease.Rupture of intracranial aneurysms can lead to subarachnoid hemorrhage(SAH).Patients with SAH may experience severe neurological symptom...BACKGROUND Intracranial blister-like microaneurysms are an extremely rare disease.Rupture of intracranial aneurysms can lead to subarachnoid hemorrhage(SAH).Patients with SAH may experience severe neurological symptoms,including severe headache,nausea,vomiting,transient or persistent loss of consciousness,limb weakness,and blurred vision.Ruptured aneurysms should be surgically treated as soon as possible.Intravascular electrocoagulation is becoming a promising treatment method for intracranial blister-like microaneurysms.The short-term follow-up results demonstrated that this method is safe and effective.This article presents a case of endovascular electrocoagulation for the treatment of a blisterlike microaneurysm.CASE SUMMARY This article reports the case of 71-year-old female patient with an intracranial aneurysm.The patient experienced a sudden headache with vomiting for 3 hours.Brain computed tomography(CT)scan showed a subarachnoid hemorrhage.She was diagnosed with rupture of an aneurysm and subarachnoid hemorrhage.The aneurysm was located in the choroidal segment of the right internal carotid artery.The size of the aneurysm was 2.00 mm×1.80 mm×1.97 mm,and the neck of the aneurysm was less than 0.5 mm wide.We successfully treated this aneurysm with endovascular electrocoagulation,and the patient was safely returned to the ward and discharged after subsequent supportive treatment.CT angiography reexamination 3 months after surgery revealed no contrast agent extravasation in the original lesion,with a good prognosis.CONCLUSION Endovascular electrocoagulation is an effective and safe method for the treatment of intracranial blister-like microaneurysms.展开更多
Narrow backfill earth pressure estimation is applied to study the stability of supporting structures in the vicinity of existing buildings.Previous narrow backfill earth pressure studies have neglected seismic-unsatur...Narrow backfill earth pressure estimation is applied to study the stability of supporting structures in the vicinity of existing buildings.Previous narrow backfill earth pressure studies have neglected seismic-unsaturated seepage multi-field coupling,resulting in inaccurate estimates.To address these deficiencies,this paper proposed a calculation method for seismic passive earth pressure in unsaturated narrow backfill,based on inclined thin-layer units.It considers the interlayer shear stress,arching effect,and the multi-field coupling of seismic-unsaturated seepage.Additionally,this paper includes a parametric sensitivity analysis.The outcomes indicate that the earthquake passive ground pressure of unsaturated narrow backfill can be reduced by increasing the aspect ratio,seismic acceleration coefficient,and unsaturation parameterα.It can also be reduced by decreasing the effective interior friction angle,soil cohesion,wallearth friction angle,and vertical discharge.Furthermore,for any width soil,lowering the elevation of the action point of passive thrust can be attained by raising the effective interior friction angle,wall-earth friction angle,and unsaturation parameterα.Reducing soil cohesion,seismic acceleration coefficient,and vertical discharge can also lower the height of the application point of passive thrust.展开更多
Organic-inorganic hybrid solar cells consisting of organic conjugated materials and inorganic quantum dots(QDs)have been of great interest during the past two decades.However,it is still challenging to select desired ...Organic-inorganic hybrid solar cells consisting of organic conjugated materials and inorganic quantum dots(QDs)have been of great interest during the past two decades.However,it is still challenging to select desired organic functional materials for fabricating hybrid films to maximize their photovoltaic performance.Herein,we report the synthesis of three narrow bandgap non-fullerene conjugated polymers and further demonstrate the importance and impact of polymer crystallinity in tuning the organic-inorganic hybrid interface towards improved photovoltaic performance.In specific,we develop an organic-inorganic hybrid active layer using a newly synthesized polymer with relatively weaker crystallinity and FAPbI_(3)QDs,enabling complementary absorption and favorable interface/morphology for efficient charge separation and transport.The champion PCDOT-T/FAPbI_(3)QD hybrid device achieves a record-high efficiency of 13.11%based on the one-step coating organic/QD hybrid bulk heterojunction blend,which is significantly improved relative to the semi-crystalline polymer PYIT-based hybrid device(11.23%)and pristine QD(10.51%).We believe these findings would provide new insight into the organic/QD interface to construct desired hybrid films for high-performing optoelectronic applications.展开更多
High-performance carbon dots(CDs)allowing the application in high-end display devices are highly desirable and usually limited by the absence of simple and easy synthesis methods.In this work,we exploited an easy-to-i...High-performance carbon dots(CDs)allowing the application in high-end display devices are highly desirable and usually limited by the absence of simple and easy synthesis methods.In this work,we exploited an easy-to-implement strategy for the one-step synthesis of green-emitting CDs(G-CDs)with superb optical properties.The G-CDs were synthesized using m-phenylenediamine(m-PD)as a single precursor,and the reaction reacted at 180℃for 12 h The resultant G-CDs exhibit high-purity and excitationindependent green fluorescence with the photoluminescence(PL)peak located at 516 nm,full width at half maximum(FWHM)of 46 nm,and PL quantum yield(QY)of∼80%under the 470nm excitation light.The G-CDs and corresponding composite film prepared with polyvinyl butyral(G-CDs@PVB)exhibit good PL stability after undergoing long-time storage for one year and 360 h exposure under 460nm blue light.The G-CDs@PVB film was used as color-conversion materials in green-emitting light-emitting diode(LED)application,exhibiting a Commission internationale de l’Eclairage(CIE)chromaticity coordinate of(0.21,0.44).The film was also used in CD-based liquid crystal display(CD-LCD)application,achieving a color gamut value of 85%.This work will offer a working basis for the synthesis of high-performance CDs as well as their application in displays.展开更多
Leaf shape is a key trait for plant architecture relating to photosynthesis and transpiration in plants(Lawson et al.,2020).Erect leaves with proper leaf length and width,particularly the upper three leaves in cereal ...Leaf shape is a key trait for plant architecture relating to photosynthesis and transpiration in plants(Lawson et al.,2020).Erect leaves with proper leaf length and width,particularly the upper three leaves in cereal crops,could significantly improve light absorption efficiency in canopy and ultimately increase crop yield(Jiao et al.,2010).Rice leaves initiate at the peripheral zone of shoot apical meristem,then develop along the proximal-distal,adaxial-abaxial,and mediallateral axes to form a flat symmetric architecture(Du et al.,2018).展开更多
Fast radio bursts(FRBs)are short-duration radio transients with mysterious origins.Since their uncertainty,there are very few FRBs observed by different instruments simultaneously.This study presents a detailed analys...Fast radio bursts(FRBs)are short-duration radio transients with mysterious origins.Since their uncertainty,there are very few FRBs observed by different instruments simultaneously.This study presents a detailed analysis of a burst from FRB 20190520B observed by FAST and Parkes at the same time.The spectrum of this individual burst ended at the upper limit of the FAST frequency band and was simultaneously detected by the Parkes telescope in the 1.5–1.8GHz range.By employing spectral energy distribution(SED)and spectral sharpness methods,we confirmed the presence of narrow-band radiation in FRB 20190520B,which is crucial for understanding its radiation mechanisms.Our findings support the narrow-band characteristics that most repeaters exhibit.This work also highlights the necessity of continued multiband observations to explore its periodicity and frequency-dependent properties,contributing to an in-depth understanding of FRB phenomena.展开更多
We report the growth of high-quality single crystals of RhP_(2),and systematically study its structure and physical properties by transport,magnetism,and heat capacity measurements.Single-crystal x-ray diffraction rev...We report the growth of high-quality single crystals of RhP_(2),and systematically study its structure and physical properties by transport,magnetism,and heat capacity measurements.Single-crystal x-ray diffraction reveals that RhP_(2) adopts a monoclinic structure with the cell parameters a=5.7347(10)A,b=5.7804(11)A,and c=5.8222(11)A,space group P2_(1)/c(No.14).The electrical resistivityρ(T)measurements indicate that RhP_(2) exhibits narrow-bandgap behavior with the activation energies of 223.1 meV and 27.4 meV for two distinct regions,respectively.The temperaturedependent Hall effect measurements show electron domain transport behavior with a low charge carrier concentration.We find that RhP_(2) has a high mobilityμ_(e)~210 cm^(2)·V^(-1)·s^(-1)with carrier concentrations n_(e)~3.3×10^(18)cm^(3) at 300 K with a narrow-bandgap feature.The high mobilityμ_(e) reaches the maximum of approximately 340 cm^(2)·V^(-1)·s^(-1)with carrier concentrations n_^(e)~2×10^(18)cm^(-3)at 100 K.No magnetic phase transitions are observed from the susceptibilityχ(T)and specific heat C_(p)(T)measurements of RhP_(2).Our results not only provide effective potential as a material platform for studying exotic physical properties and electron band structures but also motivate further exploration of their potential photovoltaic and optoelectronic applications.展开更多
The research prepared two deep ultraviolet(DUV)AlGaN-based multiple quantum well(MQW)samples with the same Al content in the QWs but different well widths(3 nm for Sample A and 2 nm for Sample B).Photoluminescence(PL)...The research prepared two deep ultraviolet(DUV)AlGaN-based multiple quantum well(MQW)samples with the same Al content in the QWs but different well widths(3 nm for Sample A and 2 nm for Sample B).Photoluminescence(PL)measurements reveal that Sample A exhibits only one main PL peak across all measured temperatures,while Sample B displays one main PL peak at low temperatures and two distinct PL peaks at high temperatures.Furthermore,compared with Sample A,Sample B exhibits a more significant temperature-dependent PL peak wavelength blue shift relative to the Varshni curve,a more significant excitation power density-dependent PL peak blue shift accompanied by linewidth broadening,as well as a larger non-radiative recombination related activation energy and higher internal quantum efficiency(IQE).These findings can be explained by the observation that the narrower well width of Sample B induces a more pronounced effect of carrier localization than the wider well width of Sample A,due to the enhanced fluctuation in well width and reduced quantum-confined Stark effect(QCSE).展开更多
Facile and efficient method for constructing carbon dots(CDs)with narrow full width at half maximum(FWHM)is a major challenge in the field,and researches on regulating the FWHM of CDs are also rare and scarce.In this ...Facile and efficient method for constructing carbon dots(CDs)with narrow full width at half maximum(FWHM)is a major challenge in the field,and researches on regulating the FWHM of CDs are also rare and scarce.In this work,we delved into the synthesis of CDs with narrow fluorescence emission FWHM(NFEF-CDs)in the m-phenylenediamine(m-PD)/ethanol system,utilizing solid superacid resin as cata-lyst with solvothermal method.The resulting NFEF-CDs exhibit a photoluminescent(PL)emission peak at 521 nm with a narrow FWHM of 41 nm,an absolute PL quantum yield(QY)of 80%,and display excitation-independent PL behavior.Through comprehensive characterization,we identified the protonation of edge amino on NFEF-CDs as the key factor in achieving the narrow FWHM.Subsequently,we validated the broad applicability of solid superacid resins as catalysts for synthesizing CDs with narrow FWHM in the m-PD/ethanol system.Finally,we utilized a self-leveling method to prepare NFEF-CDs film on the surface of poly(methyl methacrylate)(PMMA)substrate and investigated the solid-state fluorescence properties of NFEF-CDs as well as their performance as luminescence solar concentrator(LSC)for photovoltaic conver-sion.The results revealed that the as-prepared LSC exhibit an internal quantum efficiency(η_(int))of 42.39%and an optical efficiency(η_(opt))of 0.68%.These findings demonstrate the promising prospects of NFEF-CDs in the field of LSCs and provide a theoretical basis for their application in photovoltaic conversion.展开更多
A 60-mW solid-state deep ultraviolet(DUV)laser at 193 nm with narrow linewidth is obtained with two stages of sum frequency generation in LBO crystals.The pump lasers,at 258 and 1553 nm,are derived from a homemade Yb-...A 60-mW solid-state deep ultraviolet(DUV)laser at 193 nm with narrow linewidth is obtained with two stages of sum frequency generation in LBO crystals.The pump lasers,at 258 and 1553 nm,are derived from a homemade Yb-hybrid laser employing fourth-harmonic generation and Er-doped fiber laser,respectively.The Yb-hybrid laser,finally,is power scaling by a 2 mm×2 mm×30 mm Yb:YAG bulk crystal.Accompanied by the generated 220-mW DUV laser at 221 nm,the 193-nm laser delivers an average power of 60 mW with a pulse duration of 4.6 ns,a repetition rate of 6 kHz,and a linewidth of∼640 MHz.To the best of our knowledge,this is the highest power of 193-and 221-nm laser generated by an LBO crystal ever reported as well as the narrowest linewidth of 193-nm laser by it.Remarkably,the conversion efficiency reaches 27%for 221 to 193 nm and 3%for 258 to 193 nm,which are the highest efficiency values reported to date.We demonstrate the huge potential of LBO crystals for producing hundreds of milliwatt or even watt level 193-nm laser,which also paves a brand-new way to generate other DUV laser wavelengths.展开更多
Objective:To explore the implementation of gastrointestinal endoscopy technology and endoscopic narrow-band imaging(NBI)in the early screening of gastric cancer and to observe and study their application effects.Metho...Objective:To explore the implementation of gastrointestinal endoscopy technology and endoscopic narrow-band imaging(NBI)in the early screening of gastric cancer and to observe and study their application effects.Methods:During the period from March 2023 to August 2023,312 patients who received gastroscopy in the Kunming Guandu District People’s Hospital were selected,and they underwent both conventional gastroscopy and endoscopic NBI,with clinicopathological tissue biopsy serving as the gold standard.The application value for early screening of gastric cancer was observed and analyzed.Results:The scoring data showed that the clarity of gastric mucosal glandular tube structure,microvascular structure clarity,and lesion contour scoring data of conventional gastroscopy were lower than those of the NBI technology(P<0.05).The screening rate of pathological biopsy in 312 patients was 18.59%(58 cases).Conventional gastroscopy showed a screening rate of 11.53%(36 cases),while NBI technology examined a screening rate of 17.63%(55 cases),and the two-by-two comparison of the screening rate data of the three groups was not statistically significant(P>0.05).The sensitivity,specificity,accuracy,positive predictive value,and negative predictive value of conventional gastroscopy appeared to be lower than those of NBI technology(P<0.05).Conclusion:In the early screening of gastric cancer,endoscopic NBI technology can be applied to patients.Compared with conventional gastroscopy,it provides a clearer visualization of the structure of the gastric mucosal glandular structure and microvascular structure,with a certain screening rate.Additionally,its sensitivity,specificity,accuracy,positive predictive value,and negative predictive value are higher,demonstrating outstanding effectiveness.展开更多
The effect of the wide and narrow azimuth 3D observation systems on seismic imaging precision is becoming a hot area for studies of high precision 3D seismic acquisition methods in recent years. In this paper we utili...The effect of the wide and narrow azimuth 3D observation systems on seismic imaging precision is becoming a hot area for studies of high precision 3D seismic acquisition methods in recent years. In this paper we utilize 3D physical seismic modeling experiments. A 3D channel sand body physical seismic model is constructed and two acquisition systems are designed with wide azimuth （16 lines） and narrow azimuth （8 lines） to model 3D seismic data acquisition and processing seismic work flows. From analysis of migrated time slice data with high quality and small size, we conclude that when the overlying layers are smooth and lateral velocities have little change, both wide and narrow azimuth observation systems in 3D acquisition can be used for obtaining high precision imaging and equivalent resolution of the channel sand body.展开更多
Five years have passed since the Japan Narrow Band Imaging Expert Team (JNET) classification was proposed in 2014. However, the diagnostic performance of this classification has not yet been established. We conducted ...Five years have passed since the Japan Narrow Band Imaging Expert Team (JNET) classification was proposed in 2014. However, the diagnostic performance of this classification has not yet been established. We conducted a retrospective study and a systematic search of Medical Literature Analysis and Retrieval System On-Line. There were three retrospective single center studies about the diagnostic performance of this classification. In order to clarify this issue, we reviewed our study and three previous studies. This review revealed the diagnostic performance in regards to three important differentiations.(1) Neoplasia from non-neoplasia;(2) malignant neoplasia from benign neoplasia;and (3) deep submucosal invasive cancer (D-SMC) from other neoplasia. The sensitivity in differentiating neoplasia from non-neoplasia was 98.1%-99.8%. The specificity in differentiating malignant neoplasia from benign neoplasia was 84.7%-98.2% and the specificity in the differentiation D-SMC from other neoplasia was 99.8%-100.0%. This classification would enable endoscopists to identify almost all neoplasia, to appropriately determine whether to perform en bloc resection or not, and to avoid unnecessary surgery. This article is the first review about the diagnostic performance of the JNET classification. Previous reports about the diagnostic performance have all been retrospective single center studies. A large-scale prospective multicenter evaluation study is awaited for the validation.展开更多
Based on the boundary integral method, a 3D bubble breakup model in a narrow flow field is established, and a corresponding computation program is developed to simulate the symmetrical and asymmetrical bubble breakup....Based on the boundary integral method, a 3D bubble breakup model in a narrow flow field is established, and a corresponding computation program is developed to simulate the symmetrical and asymmetrical bubble breakup. The calculated results are compared with the experimental results and agree with them very well, indicating that the numerical model is valid. Based on the basic behavior of bubbles in a narrow flow field, the symmetrical and asymmetrical bubble breakup is studied systematically using the developed program. A feasibility rule of 3D bubble breakup is presented. The dynamics of sub-bubbles after splitting is studied. The influences of characteristic parameters on bubble breakup and sub-bubble dynamics are analyzed.展开更多
Based on the construction of reference e le ment and bilinear transformation, a quasi-Wilson element for arbitrary narrow q uadrilateral is presented. Using the interpolation Theorem for narrow quadrilate ral isoparam...Based on the construction of reference e le ment and bilinear transformation, a quasi-Wilson element for arbitrary narrow q uadrilateral is presented. Using the interpolation Theorem for narrow quadrilate ral isoparametric finite element and related methods, the bounds of interpolatio n error for arbitrary narrow quadrilateral quasi-Wilson element are obtained in case when the condition ρ K/h K≥σ 0】0 is not satisfied, where h K is the diameter of the element K and ρ K is the diameter of an ins cribed circle in K. The interpolation error is O(h2 K) in the L2( K)-norm and O(h K) in the H1(K) -norm provided that the in terpolated function belongs to H2(K).展开更多
Spectrally-selective photodetection plays a crucial role in various applications,including target imaging and environmental monitoring.Traditional deep-ultraviolet(DUV)narrowband photodetection systems consist of broa...Spectrally-selective photodetection plays a crucial role in various applications,including target imaging and environmental monitoring.Traditional deep-ultraviolet(DUV)narrowband photodetection systems consist of broadband photodetectors and filters,which complicates the architecture and constrains imaging quality.Here,we introduce an electronic-grade diamond single-crystal photodetector exhibiting an exceptionally narrow spectral response in the DUV range with a full width at half maximum of 8 nm.By examining diamond photodetectors with varying dislocation densities,we propose that mitigating the defect-induced trapping effect to achieve charge collection narrowing,assisted by free exciton radiative recombination,is an effective strategy for narrowband photodetection.The superior performance of this device is evidenced through the imaging of DUV light sources,showcasing its capability to differentiate between distinct light sources and monitor human-safe sterilization systems.Our findings underscore the promising potential applications of electronicgrade diamond in narrowband photodetection and offer a valuable technique for identifying electronic-grade diamond.展开更多
Background:Tree species with narrow ranges are a conservation concern because heightened extinction risk accompanies their small populations.Assessing risks for these species is challenging,however,especially in tropi...Background:Tree species with narrow ranges are a conservation concern because heightened extinction risk accompanies their small populations.Assessing risks for these species is challenging,however,especially in tropical flora where their sparse populations seldom appear in traditional plots and inventories.Here,we utilize instead large scale databases that combine tree records from many sources to test whether the narrow-range tree species of Panama are concentrated at certain elevations or in certain provinces.Past investigations have suggested that the Choco region of eastern Panama and the high mountains of western Panama may be potential hotspots of narrow-range tree species.Methods:All individual records were collected from public databases,and the range size of each tree species found in Panama was estimated as a polygon enclosing all its locations.Species with ranges<20,000 km^(2) were defined as narrow endemics.We divided Panama into geographic regions and elevation zones and counted the number of individual records and the species richness in each,separating narrow-range species from all other species.Results:The proportion of narrow endemics peaked at elevations above 2000 m,reaching 17.2% of the species recorded.At elevation<1500 m across the country,the proportion was 6-11%,except in the dry Pacific region,where it was 1.5%.Wet forests of the Caribbean coast had 8.4% narrow-range species,slightly higher than other regions.The total number of narrow endemics,however,peaked at mid-elevation,not high elevation,because total species richness was highest at mid-elevation.Conclusions:High elevation forests of west Panama had higher proportions of narrow endemic trees than low-elevation regions,supporting their hot-spot status,while dry lowland forests had the lowest proportion.This supports the notion that montane forests of Central America should be a conservation focus.However,given generally higher diversity at low-to mid-elevation,lowlands are also important habitats for narrow-range tree species,though conservation efforts here may not protect narrow-range tree species as efficiently.展开更多
In the context of current climate change, an abnormality of flooding is a common form of disaster in Vietnam. Hanh Stream reservoir has occurred great flood in 1986, 2010. In the future, the risk of flooding is possib...In the context of current climate change, an abnormality of flooding is a common form of disaster in Vietnam. Hanh Stream reservoir has occurred great flood in 1986, 2010. In the future, the risk of flooding is possible to happen again. In view of management of the risk of natural disasters： large flooding situation downstream is one of the most dangerous risks for the reservoir. Due to downstream of Hanh Stream reservoir is a narrow coastal plains, quick infrastructure development, especially interwoven road and railway systems, so that flood drainage ability will be affected greatly. The consciousness of risks that may be occurred in the future in order to propose preventive measures and proactive response to minimize damages always is the requirement for all projects. The hydrodynamic calculation, flooding maps, emergency plan to prevent flooding downstream of Hanh Stream reservoir is also needed. The article is raised the issue of requirements to calculate coastal narrow delta strip flooding in the Central of Vietnam when impacted by the upstream reservoir of flood discharge in terms of extreme heavy rain and flooding and presented computational methods of Mike software package for case flooded plain of Cam Ranh Bay in downstream reservoirs of Hanh Stream, Khanh Hoa Province, Vietnam.展开更多
AIM: To determine whether the endoscopic findings of depressed-type early gastric cancers(EGCs) could precisely predict the histological type.METHODS: Ninety depressed-type EGCs in 72 patients were macroscopically and...AIM: To determine whether the endoscopic findings of depressed-type early gastric cancers(EGCs) could precisely predict the histological type.METHODS: Ninety depressed-type EGCs in 72 patients were macroscopically and histologically identified. We evaluated the microvascular(MV) and mucosal surface(MS) patterns of depressed-type EGCs using magnifying endoscopy(ME) with narrow-band imaging(NBI)(NBI-ME) and ME enhanced by 1.5% acetic acid, respectively. First, depressed-type EGCs were classified according to MV pattern by NBI-ME. Subsequently, EGCs unclassified by MV pattern were classified according to MS pattern by enhanced ME(EME) images obtained from the same angle.RESULTS: We classified the depressed-type EGCs into the following 2 MV patterns using NBI-ME: a fine-network pattern that indicated differentiated adenocarcinoma(25/25, 100%) and a corkscrew pattern that likely indicated undifferentiated adenocarcinoma(18/23, 78.3%). However, 42 of the 90(46.7%) lesions could not be classified into MV patterns by NBI-ME. These unclassified lesions were then evaluated for MS patterns using EME, which classified 33(81.0%) lesions as MS patterns, diagnosed as differentiated adenocarcinoma. As a result, 76 of the 90(84.4%) lesions were matched with histological diagnoses using a combination of NBI-ME and EME.CONCLUSION: A combination of NBI-ME and EME was useful in predicting the histological type of depressedtype EGC.展开更多
Endoscopy plays an important role in the diagnosis and management of gastrointestinal(GI)tract disorders.Chromoendoscopy has proven to be superior to white light endoscopy for early detection of various GI lesions.Thi...Endoscopy plays an important role in the diagnosis and management of gastrointestinal(GI)tract disorders.Chromoendoscopy has proven to be superior to white light endoscopy for early detection of various GI lesions.This has however been fraught with problems.The use of color stains,time taken to achieve an effect and the learning curve associated with the technique has been some of the pitfalls.Narrow band imaging(NBI)particularly in combination with magnifying endoscopy may allow the endoscopist to accomplish a fairly accurate diagnosis with good histological correlation similar to results achieved with chromoendoscopy.Such enhanced detection of pre-malignant and early neoplastic lesions in the gastrointestinal tract should allow better targeting of biopsies and could ultimately prove to be cost effective.Various studies have been done demonstrating the utility of this novel technology.This article will review the impact of NBI in the diagnosis of upper gastrointestinal tract disorders.展开更多
文摘BACKGROUND Intracranial blister-like microaneurysms are an extremely rare disease.Rupture of intracranial aneurysms can lead to subarachnoid hemorrhage(SAH).Patients with SAH may experience severe neurological symptoms,including severe headache,nausea,vomiting,transient or persistent loss of consciousness,limb weakness,and blurred vision.Ruptured aneurysms should be surgically treated as soon as possible.Intravascular electrocoagulation is becoming a promising treatment method for intracranial blister-like microaneurysms.The short-term follow-up results demonstrated that this method is safe and effective.This article presents a case of endovascular electrocoagulation for the treatment of a blisterlike microaneurysm.CASE SUMMARY This article reports the case of 71-year-old female patient with an intracranial aneurysm.The patient experienced a sudden headache with vomiting for 3 hours.Brain computed tomography(CT)scan showed a subarachnoid hemorrhage.She was diagnosed with rupture of an aneurysm and subarachnoid hemorrhage.The aneurysm was located in the choroidal segment of the right internal carotid artery.The size of the aneurysm was 2.00 mm×1.80 mm×1.97 mm,and the neck of the aneurysm was less than 0.5 mm wide.We successfully treated this aneurysm with endovascular electrocoagulation,and the patient was safely returned to the ward and discharged after subsequent supportive treatment.CT angiography reexamination 3 months after surgery revealed no contrast agent extravasation in the original lesion,with a good prognosis.CONCLUSION Endovascular electrocoagulation is an effective and safe method for the treatment of intracranial blister-like microaneurysms.
基金Project(42277175)supported by the National Natural Science Foundation of ChinaProject(NRMSSHR-2022-Z08)supported by the Key Laboratory of Natural Resources Monitoring and Supervision in Southern Hilly Region,Ministry of Natural Resources,China。
文摘Narrow backfill earth pressure estimation is applied to study the stability of supporting structures in the vicinity of existing buildings.Previous narrow backfill earth pressure studies have neglected seismic-unsaturated seepage multi-field coupling,resulting in inaccurate estimates.To address these deficiencies,this paper proposed a calculation method for seismic passive earth pressure in unsaturated narrow backfill,based on inclined thin-layer units.It considers the interlayer shear stress,arching effect,and the multi-field coupling of seismic-unsaturated seepage.Additionally,this paper includes a parametric sensitivity analysis.The outcomes indicate that the earthquake passive ground pressure of unsaturated narrow backfill can be reduced by increasing the aspect ratio,seismic acceleration coefficient,and unsaturation parameterα.It can also be reduced by decreasing the effective interior friction angle,soil cohesion,wallearth friction angle,and vertical discharge.Furthermore,for any width soil,lowering the elevation of the action point of passive thrust can be attained by raising the effective interior friction angle,wall-earth friction angle,and unsaturation parameterα.Reducing soil cohesion,seismic acceleration coefficient,and vertical discharge can also lower the height of the application point of passive thrust.
基金financially supported by the National Key Research and Development Program of China(2022YFE0110300)the National Natural Science Foundation of China(52261145696 and 52473187)+1 种基金the“111”Projectthe Collaborative Innovation Center of Suzhou Nano Science and Technology,Soochow University。
文摘Organic-inorganic hybrid solar cells consisting of organic conjugated materials and inorganic quantum dots(QDs)have been of great interest during the past two decades.However,it is still challenging to select desired organic functional materials for fabricating hybrid films to maximize their photovoltaic performance.Herein,we report the synthesis of three narrow bandgap non-fullerene conjugated polymers and further demonstrate the importance and impact of polymer crystallinity in tuning the organic-inorganic hybrid interface towards improved photovoltaic performance.In specific,we develop an organic-inorganic hybrid active layer using a newly synthesized polymer with relatively weaker crystallinity and FAPbI_(3)QDs,enabling complementary absorption and favorable interface/morphology for efficient charge separation and transport.The champion PCDOT-T/FAPbI_(3)QD hybrid device achieves a record-high efficiency of 13.11%based on the one-step coating organic/QD hybrid bulk heterojunction blend,which is significantly improved relative to the semi-crystalline polymer PYIT-based hybrid device(11.23%)and pristine QD(10.51%).We believe these findings would provide new insight into the organic/QD interface to construct desired hybrid films for high-performing optoelectronic applications.
基金supported by the Jiangsu Funding Program for Excellent Postdoctoral Talent(No.2022ZB369)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘High-performance carbon dots(CDs)allowing the application in high-end display devices are highly desirable and usually limited by the absence of simple and easy synthesis methods.In this work,we exploited an easy-to-implement strategy for the one-step synthesis of green-emitting CDs(G-CDs)with superb optical properties.The G-CDs were synthesized using m-phenylenediamine(m-PD)as a single precursor,and the reaction reacted at 180℃for 12 h The resultant G-CDs exhibit high-purity and excitationindependent green fluorescence with the photoluminescence(PL)peak located at 516 nm,full width at half maximum(FWHM)of 46 nm,and PL quantum yield(QY)of∼80%under the 470nm excitation light.The G-CDs and corresponding composite film prepared with polyvinyl butyral(G-CDs@PVB)exhibit good PL stability after undergoing long-time storage for one year and 360 h exposure under 460nm blue light.The G-CDs@PVB film was used as color-conversion materials in green-emitting light-emitting diode(LED)application,exhibiting a Commission internationale de l’Eclairage(CIE)chromaticity coordinate of(0.21,0.44).The film was also used in CD-based liquid crystal display(CD-LCD)application,achieving a color gamut value of 85%.This work will offer a working basis for the synthesis of high-performance CDs as well as their application in displays.
基金supported by the Open Competition Program of the Top Ten Critical Priorities of Agricultural Science and Technology Innovation for the 14th Five-Year Plan of Guangdong Province(No.2022SDZG05)to Letian Chenthe Major Program of Guangdong Basic and Applied Research(2019B030302006)+3 种基金Laboratory of Lingnan Modern Agriculture Project(NT2021002)to Yaoguang Liuthe Foundation of Hainan Yazhou Bay Seed Laboratory(B23YQ1515,B23CQ15FP)to Rongxin Shenthe National Natural Science Foundation of China(32270698)the Elite Rice Plan of GDRRI(2022YG01)to Qi Liu.
文摘Leaf shape is a key trait for plant architecture relating to photosynthesis and transpiration in plants(Lawson et al.,2020).Erect leaves with proper leaf length and width,particularly the upper three leaves in cereal crops,could significantly improve light absorption efficiency in canopy and ultimately increase crop yield(Jiao et al.,2010).Rice leaves initiate at the peripheral zone of shoot apical meristem,then develop along the proximal-distal,adaxial-abaxial,and mediallateral axes to form a flat symmetric architecture(Du et al.,2018).
基金supported by the National Natural Science Foundation of China(Grant Nos.11988101,12203069,12041302,and 12203045)the National SKA Program of China(Grant No.2022SKA0130100)+8 种基金the Office of the Leading Group for Cyberspace Affairs,CAS(Grant No.CAS-WX2023PY0102)the CAS Youth Interdisciplinary Team and the Foundation of Guizhou Provincial Education Department(Grant No.KY(2023)059)support from the National Natural Science Foundation of China(Grant Nos.11988101 and 12041303)the CAS Youth Interdisciplinary Team,the Youth Innovation Promotion Association CAS(Grant No.2021055)the Cultivation Project for FAST Scientific Payoff and Research Achievement of CAMS-CASsupported by the National Natural Science Foundation of China(Grant No.12203045)the Leading Innovation and Entrepreneurship Team of Zhejiang Province of China(Grant No.2023R01008)the Key R&D Program of Zhejiang(Grant No.2024SSYS0012)supported by the China Scholarship Council(Grant No.202304910441)。
文摘Fast radio bursts(FRBs)are short-duration radio transients with mysterious origins.Since their uncertainty,there are very few FRBs observed by different instruments simultaneously.This study presents a detailed analysis of a burst from FRB 20190520B observed by FAST and Parkes at the same time.The spectrum of this individual burst ended at the upper limit of the FAST frequency band and was simultaneously detected by the Parkes telescope in the 1.5–1.8GHz range.By employing spectral energy distribution(SED)and spectral sharpness methods,we confirmed the presence of narrow-band radiation in FRB 20190520B,which is crucial for understanding its radiation mechanisms.Our findings support the narrow-band characteristics that most repeaters exhibit.This work also highlights the necessity of continued multiband observations to explore its periodicity and frequency-dependent properties,contributing to an in-depth understanding of FRB phenomena.
基金supported by the National Key Research and Development Program of China (Grant No.2017YFA0302901)the Strategic Priority Research Program,the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences (Grant No.XDB33010100)+3 种基金the National Natural Science Foundation of China (Grant Nos.12134018,11921004,and 11634015)the Foundation of Quantum Science Center of Guangdong–Hong Kong–Macao Greater Bay Area,China (Grant No.QD2301005)the Postdoctoral Science Foundation of China (Grant No.2021M693370)the Synergetic Extreme Condition User Facility (SECUF)。
文摘We report the growth of high-quality single crystals of RhP_(2),and systematically study its structure and physical properties by transport,magnetism,and heat capacity measurements.Single-crystal x-ray diffraction reveals that RhP_(2) adopts a monoclinic structure with the cell parameters a=5.7347(10)A,b=5.7804(11)A,and c=5.8222(11)A,space group P2_(1)/c(No.14).The electrical resistivityρ(T)measurements indicate that RhP_(2) exhibits narrow-bandgap behavior with the activation energies of 223.1 meV and 27.4 meV for two distinct regions,respectively.The temperaturedependent Hall effect measurements show electron domain transport behavior with a low charge carrier concentration.We find that RhP_(2) has a high mobilityμ_(e)~210 cm^(2)·V^(-1)·s^(-1)with carrier concentrations n_(e)~3.3×10^(18)cm^(3) at 300 K with a narrow-bandgap feature.The high mobilityμ_(e) reaches the maximum of approximately 340 cm^(2)·V^(-1)·s^(-1)with carrier concentrations n_^(e)~2×10^(18)cm^(-3)at 100 K.No magnetic phase transitions are observed from the susceptibilityχ(T)and specific heat C_(p)(T)measurements of RhP_(2).Our results not only provide effective potential as a material platform for studying exotic physical properties and electron band structures but also motivate further exploration of their potential photovoltaic and optoelectronic applications.
基金supported by the National Natural Science Foundation of China(Nos.62135013,62274163 and 52272157)the Wuxi Innovation and Entrepreneurship Fund“Taihu Light”Science and Technology(Fundamental Research)Project(No.K20231002)。
文摘The research prepared two deep ultraviolet(DUV)AlGaN-based multiple quantum well(MQW)samples with the same Al content in the QWs but different well widths(3 nm for Sample A and 2 nm for Sample B).Photoluminescence(PL)measurements reveal that Sample A exhibits only one main PL peak across all measured temperatures,while Sample B displays one main PL peak at low temperatures and two distinct PL peaks at high temperatures.Furthermore,compared with Sample A,Sample B exhibits a more significant temperature-dependent PL peak wavelength blue shift relative to the Varshni curve,a more significant excitation power density-dependent PL peak blue shift accompanied by linewidth broadening,as well as a larger non-radiative recombination related activation energy and higher internal quantum efficiency(IQE).These findings can be explained by the observation that the narrower well width of Sample B induces a more pronounced effect of carrier localization than the wider well width of Sample A,due to the enhanced fluctuation in well width and reduced quantum-confined Stark effect(QCSE).
基金supported by the National Natural Science Foundation of China(No.22308161)the Jiangsu Funding Program for Excellent Postdoctoral Talent(No.2022ZB369),Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Facile and efficient method for constructing carbon dots(CDs)with narrow full width at half maximum(FWHM)is a major challenge in the field,and researches on regulating the FWHM of CDs are also rare and scarce.In this work,we delved into the synthesis of CDs with narrow fluorescence emission FWHM(NFEF-CDs)in the m-phenylenediamine(m-PD)/ethanol system,utilizing solid superacid resin as cata-lyst with solvothermal method.The resulting NFEF-CDs exhibit a photoluminescent(PL)emission peak at 521 nm with a narrow FWHM of 41 nm,an absolute PL quantum yield(QY)of 80%,and display excitation-independent PL behavior.Through comprehensive characterization,we identified the protonation of edge amino on NFEF-CDs as the key factor in achieving the narrow FWHM.Subsequently,we validated the broad applicability of solid superacid resins as catalysts for synthesizing CDs with narrow FWHM in the m-PD/ethanol system.Finally,we utilized a self-leveling method to prepare NFEF-CDs film on the surface of poly(methyl methacrylate)(PMMA)substrate and investigated the solid-state fluorescence properties of NFEF-CDs as well as their performance as luminescence solar concentrator(LSC)for photovoltaic conver-sion.The results revealed that the as-prepared LSC exhibit an internal quantum efficiency(η_(int))of 42.39%and an optical efficiency(η_(opt))of 0.68%.These findings demonstrate the promising prospects of NFEF-CDs in the field of LSCs and provide a theoretical basis for their application in photovoltaic conversion.
基金supported by the Research Project of Aerospace Information Research Institute,Chinese Academy of Sciences (Grant Nos.E1Z1D101 and E2Z2D101)the Project of Chinese Academy of Sciences (Grant No.E33310030D)the Guangzhou Basic and Applied Basic Research Foundation (Grant Nos.2023A04J0336 and 2023A04J0021).
文摘A 60-mW solid-state deep ultraviolet(DUV)laser at 193 nm with narrow linewidth is obtained with two stages of sum frequency generation in LBO crystals.The pump lasers,at 258 and 1553 nm,are derived from a homemade Yb-hybrid laser employing fourth-harmonic generation and Er-doped fiber laser,respectively.The Yb-hybrid laser,finally,is power scaling by a 2 mm×2 mm×30 mm Yb:YAG bulk crystal.Accompanied by the generated 220-mW DUV laser at 221 nm,the 193-nm laser delivers an average power of 60 mW with a pulse duration of 4.6 ns,a repetition rate of 6 kHz,and a linewidth of∼640 MHz.To the best of our knowledge,this is the highest power of 193-and 221-nm laser generated by an LBO crystal ever reported as well as the narrowest linewidth of 193-nm laser by it.Remarkably,the conversion efficiency reaches 27%for 221 to 193 nm and 3%for 258 to 193 nm,which are the highest efficiency values reported to date.We demonstrate the huge potential of LBO crystals for producing hundreds of milliwatt or even watt level 193-nm laser,which also paves a brand-new way to generate other DUV laser wavelengths.
文摘Objective:To explore the implementation of gastrointestinal endoscopy technology and endoscopic narrow-band imaging(NBI)in the early screening of gastric cancer and to observe and study their application effects.Methods:During the period from March 2023 to August 2023,312 patients who received gastroscopy in the Kunming Guandu District People’s Hospital were selected,and they underwent both conventional gastroscopy and endoscopic NBI,with clinicopathological tissue biopsy serving as the gold standard.The application value for early screening of gastric cancer was observed and analyzed.Results:The scoring data showed that the clarity of gastric mucosal glandular tube structure,microvascular structure clarity,and lesion contour scoring data of conventional gastroscopy were lower than those of the NBI technology(P<0.05).The screening rate of pathological biopsy in 312 patients was 18.59%(58 cases).Conventional gastroscopy showed a screening rate of 11.53%(36 cases),while NBI technology examined a screening rate of 17.63%(55 cases),and the two-by-two comparison of the screening rate data of the three groups was not statistically significant(P>0.05).The sensitivity,specificity,accuracy,positive predictive value,and negative predictive value of conventional gastroscopy appeared to be lower than those of NBI technology(P<0.05).Conclusion:In the early screening of gastric cancer,endoscopic NBI technology can be applied to patients.Compared with conventional gastroscopy,it provides a clearer visualization of the structure of the gastric mucosal glandular structure and microvascular structure,with a certain screening rate.Additionally,its sensitivity,specificity,accuracy,positive predictive value,and negative predictive value are higher,demonstrating outstanding effectiveness.
基金supported by the National Basic Research Program (the 973 Program, No. 2007CB209601).
文摘The effect of the wide and narrow azimuth 3D observation systems on seismic imaging precision is becoming a hot area for studies of high precision 3D seismic acquisition methods in recent years. In this paper we utilize 3D physical seismic modeling experiments. A 3D channel sand body physical seismic model is constructed and two acquisition systems are designed with wide azimuth （16 lines） and narrow azimuth （8 lines） to model 3D seismic data acquisition and processing seismic work flows. From analysis of migrated time slice data with high quality and small size, we conclude that when the overlying layers are smooth and lateral velocities have little change, both wide and narrow azimuth observation systems in 3D acquisition can be used for obtaining high precision imaging and equivalent resolution of the channel sand body.
文摘Five years have passed since the Japan Narrow Band Imaging Expert Team (JNET) classification was proposed in 2014. However, the diagnostic performance of this classification has not yet been established. We conducted a retrospective study and a systematic search of Medical Literature Analysis and Retrieval System On-Line. There were three retrospective single center studies about the diagnostic performance of this classification. In order to clarify this issue, we reviewed our study and three previous studies. This review revealed the diagnostic performance in regards to three important differentiations.(1) Neoplasia from non-neoplasia;(2) malignant neoplasia from benign neoplasia;and (3) deep submucosal invasive cancer (D-SMC) from other neoplasia. The sensitivity in differentiating neoplasia from non-neoplasia was 98.1%-99.8%. The specificity in differentiating malignant neoplasia from benign neoplasia was 84.7%-98.2% and the specificity in the differentiation D-SMC from other neoplasia was 99.8%-100.0%. This classification would enable endoscopists to identify almost all neoplasia, to appropriately determine whether to perform en bloc resection or not, and to avoid unnecessary surgery. This article is the first review about the diagnostic performance of the JNET classification. Previous reports about the diagnostic performance have all been retrospective single center studies. A large-scale prospective multicenter evaluation study is awaited for the validation.
基金Project supported by the National Natural Science Foundation of China (No. 50779007)the International Science and Technology Cooperation Project (No. 2007DFR80340)+1 种基金the National Science Foundation for Young Scientists of China (No. 50809018)the Postdoctoral Science Foundation of China (No. 200801104)
文摘Based on the boundary integral method, a 3D bubble breakup model in a narrow flow field is established, and a corresponding computation program is developed to simulate the symmetrical and asymmetrical bubble breakup. The calculated results are compared with the experimental results and agree with them very well, indicating that the numerical model is valid. Based on the basic behavior of bubbles in a narrow flow field, the symmetrical and asymmetrical bubble breakup is studied systematically using the developed program. A feasibility rule of 3D bubble breakup is presented. The dynamics of sub-bubbles after splitting is studied. The influences of characteristic parameters on bubble breakup and sub-bubble dynamics are analyzed.
文摘Based on the construction of reference e le ment and bilinear transformation, a quasi-Wilson element for arbitrary narrow q uadrilateral is presented. Using the interpolation Theorem for narrow quadrilate ral isoparametric finite element and related methods, the bounds of interpolatio n error for arbitrary narrow quadrilateral quasi-Wilson element are obtained in case when the condition ρ K/h K≥σ 0】0 is not satisfied, where h K is the diameter of the element K and ρ K is the diameter of an ins cribed circle in K. The interpolation error is O(h2 K) in the L2( K)-norm and O(h K) in the H1(K) -norm provided that the in terpolated function belongs to H2(K).
基金supports from Natural Science Foundation of Guangdong Province for Distinguished Young Scholars(Grant No.2021B1515020105).
文摘Spectrally-selective photodetection plays a crucial role in various applications,including target imaging and environmental monitoring.Traditional deep-ultraviolet(DUV)narrowband photodetection systems consist of broadband photodetectors and filters,which complicates the architecture and constrains imaging quality.Here,we introduce an electronic-grade diamond single-crystal photodetector exhibiting an exceptionally narrow spectral response in the DUV range with a full width at half maximum of 8 nm.By examining diamond photodetectors with varying dislocation densities,we propose that mitigating the defect-induced trapping effect to achieve charge collection narrowing,assisted by free exciton radiative recombination,is an effective strategy for narrowband photodetection.The superior performance of this device is evidenced through the imaging of DUV light sources,showcasing its capability to differentiate between distinct light sources and monitor human-safe sterilization systems.Our findings underscore the promising potential applications of electronicgrade diamond in narrowband photodetection and offer a valuable technique for identifying electronic-grade diamond.
基金The Center for Tree Science at the Morton Arboretum provided financial support for the lead authorby the Smithsonian Institution and the National Science Foundation(US).
文摘Background:Tree species with narrow ranges are a conservation concern because heightened extinction risk accompanies their small populations.Assessing risks for these species is challenging,however,especially in tropical flora where their sparse populations seldom appear in traditional plots and inventories.Here,we utilize instead large scale databases that combine tree records from many sources to test whether the narrow-range tree species of Panama are concentrated at certain elevations or in certain provinces.Past investigations have suggested that the Choco region of eastern Panama and the high mountains of western Panama may be potential hotspots of narrow-range tree species.Methods:All individual records were collected from public databases,and the range size of each tree species found in Panama was estimated as a polygon enclosing all its locations.Species with ranges<20,000 km^(2) were defined as narrow endemics.We divided Panama into geographic regions and elevation zones and counted the number of individual records and the species richness in each,separating narrow-range species from all other species.Results:The proportion of narrow endemics peaked at elevations above 2000 m,reaching 17.2% of the species recorded.At elevation<1500 m across the country,the proportion was 6-11%,except in the dry Pacific region,where it was 1.5%.Wet forests of the Caribbean coast had 8.4% narrow-range species,slightly higher than other regions.The total number of narrow endemics,however,peaked at mid-elevation,not high elevation,because total species richness was highest at mid-elevation.Conclusions:High elevation forests of west Panama had higher proportions of narrow endemic trees than low-elevation regions,supporting their hot-spot status,while dry lowland forests had the lowest proportion.This supports the notion that montane forests of Central America should be a conservation focus.However,given generally higher diversity at low-to mid-elevation,lowlands are also important habitats for narrow-range tree species,though conservation efforts here may not protect narrow-range tree species as efficiently.
文摘In the context of current climate change, an abnormality of flooding is a common form of disaster in Vietnam. Hanh Stream reservoir has occurred great flood in 1986, 2010. In the future, the risk of flooding is possible to happen again. In view of management of the risk of natural disasters： large flooding situation downstream is one of the most dangerous risks for the reservoir. Due to downstream of Hanh Stream reservoir is a narrow coastal plains, quick infrastructure development, especially interwoven road and railway systems, so that flood drainage ability will be affected greatly. The consciousness of risks that may be occurred in the future in order to propose preventive measures and proactive response to minimize damages always is the requirement for all projects. The hydrodynamic calculation, flooding maps, emergency plan to prevent flooding downstream of Hanh Stream reservoir is also needed. The article is raised the issue of requirements to calculate coastal narrow delta strip flooding in the Central of Vietnam when impacted by the upstream reservoir of flood discharge in terms of extreme heavy rain and flooding and presented computational methods of Mike software package for case flooded plain of Cam Ranh Bay in downstream reservoirs of Hanh Stream, Khanh Hoa Province, Vietnam.
文摘AIM: To determine whether the endoscopic findings of depressed-type early gastric cancers(EGCs) could precisely predict the histological type.METHODS: Ninety depressed-type EGCs in 72 patients were macroscopically and histologically identified. We evaluated the microvascular(MV) and mucosal surface(MS) patterns of depressed-type EGCs using magnifying endoscopy(ME) with narrow-band imaging(NBI)(NBI-ME) and ME enhanced by 1.5% acetic acid, respectively. First, depressed-type EGCs were classified according to MV pattern by NBI-ME. Subsequently, EGCs unclassified by MV pattern were classified according to MS pattern by enhanced ME(EME) images obtained from the same angle.RESULTS: We classified the depressed-type EGCs into the following 2 MV patterns using NBI-ME: a fine-network pattern that indicated differentiated adenocarcinoma(25/25, 100%) and a corkscrew pattern that likely indicated undifferentiated adenocarcinoma(18/23, 78.3%). However, 42 of the 90(46.7%) lesions could not be classified into MV patterns by NBI-ME. These unclassified lesions were then evaluated for MS patterns using EME, which classified 33(81.0%) lesions as MS patterns, diagnosed as differentiated adenocarcinoma. As a result, 76 of the 90(84.4%) lesions were matched with histological diagnoses using a combination of NBI-ME and EME.CONCLUSION: A combination of NBI-ME and EME was useful in predicting the histological type of depressedtype EGC.
文摘Endoscopy plays an important role in the diagnosis and management of gastrointestinal(GI)tract disorders.Chromoendoscopy has proven to be superior to white light endoscopy for early detection of various GI lesions.This has however been fraught with problems.The use of color stains,time taken to achieve an effect and the learning curve associated with the technique has been some of the pitfalls.Narrow band imaging(NBI)particularly in combination with magnifying endoscopy may allow the endoscopist to accomplish a fairly accurate diagnosis with good histological correlation similar to results achieved with chromoendoscopy.Such enhanced detection of pre-malignant and early neoplastic lesions in the gastrointestinal tract should allow better targeting of biopsies and could ultimately prove to be cost effective.Various studies have been done demonstrating the utility of this novel technology.This article will review the impact of NBI in the diagnosis of upper gastrointestinal tract disorders.
