Influence of Tumor Characteristics on Visual Field Outcomes After Pituitary Adenoma Surgery.

BACKGROUND: There were few reports about the influence of tumor characteristics on the postoperative visual field outcomes after transsphenoidal surgery for pituitary adenoma. The purpose of this study was to explore the tumor characteristics that influenced perioperative visual field changes. METHODS: Patients who underwent transsphenoidal surgery under a diagnosis of pituitary adenoma at the Kyoto University Hospital between April 2012 and December 2018 were retrospectively enrolled. Correlations among circumpapillary retinal nerve fiber layer thickness, preoperative and postoperative mean deviation (MD) of visual field, MD change after the surgery, and maximum tumor diameter were evaluated by measuring Pearson correlation coefficient. We evaluated the influences on postoperative MD using a generalized estimating equation for univariate and multivariate regression analyses. We also compared the characteristics of cystic and solid tumors. RESULTS: Thirty-two eyes of 18 patients were included in this study (9 male and 9 female patients). Postoperative MD positively correlated with maximum tumor diameter only in multivariate regression {ß = 0.22 (95% confidence interval [CI], 0.004-0.43), P = 0.046}, although maximum tumor diameter negatively correlated with postoperative MD in univariate regression (ß = -0.16 [95% CI, -0.58 to 0.26], P = 0.46). In the investigation of perioperative MD changes, eyes with cystic tumors showed significantly better improvement those with solid tumors (8.93 ± 7.85 vs 0.18 ± 6.56 dB, P = 0.007). CONCLUSIONS: Cystic and solid tumors show different characteristics of visual loss and visual field defects. The MD in eyes with cystic tumors improved significantly more than that in eyes with solid tumors.

DNA-functionalized colloidal crystals for macromolecular encapsulation.

Novel DNA-based structures with the ability to encapsulate nanoscale molecules, such as proteins, can be applied to a wide range of areas, including reaction fields and micro/nano drug carriers. DNA-functionalized nanoparticle (DNA-NP) colloidal crystals have emerged as a new class of programmable DNA-based structures harboring metal nanoparticles with improved mechanical properties. The encapsulation of guest molecules into empty spaces in lattice structures is theoretically possible. However, due to the lack of a strategy for versatile encapsulation of guest molecules, the feasibility of nanoscale encapsulation by DNA-NP crystals is unclear. In this study, we developed DNA-functionalized gold nanoparticle (DNA-AuNP) crystals with tunable interparticle spacing for molecular encapsulation. We demonstrated that the modification of DNA-AuNP crystals with functional moieties, that is, biotin molecules, was effective in retaining molecules in the crystals. The crystallinities before and after encapsulation of the molecules were confirmed using small-angle X-ray scattering. We also succeeded in encapsulating CRISPR/Cas9 ribonucleoproteins into DNA-AuNP crystals by harnessing their affinity for target molecules. These findings demonstrated the potential use of metal-DNA hybrid crystals as carriers for direct protein delivery via biolistic bombardment. Thus, this study provides an attractive strategy for creating a new class of DNA-based structures for macromolecular encapsulation, and an alternative research direction toward colloidal crystal engineering using DNA.

Deterioration of phagocytosis in induced pluripotent stem cell-derived retinal pigment epithelial cells established from patients with retinitis pigmentosa carrying Mer tyrosine kinase mutations.

Retinitis pigmentosa (RP) is an incurable retinal degenerative disease with an unknown mechanism of disease progression. Mer tyrosine kinase (MERTK), which encodes a receptor of the Tyro3/Axl/Mer family of tyrosine kinases, is one of the causal genes of RP. MERTK is reportedly expressed in the retinal pigment epithelium (RPE) and is essential for phagocytosis of the photoreceptor outer segment. Here, we established induced pluripotent stem cells (iPSC) from patients with RP having homozygous or compound heterozygous mutations in MERTK, and from healthy subjects; the RP patient- and healthy control-derived iPSCs were differentiated into RPE cells. Although cytoskeleton staining suggested that polarity may have been disturbed mildly, there were no apparent morphological differences between the diseased and normal RPE cells. The internalization of photoreceptor outer segments in diseased iPSC-RPE cells was significantly lower than that in normal iPSC-RPE cells. This in vitro disease model may be useful for elucidating the mechanisms of disease progression and screening treatments for the disease.

Prognostic Impact of Placental Growth Factor on Mortality and Cardiovascular Events in Dialysis Patients.

BACKGROUND: Placental growth factor (PlGF), a member of the vascular endothelial growth factor (VEGF) family, has recently emerged as a predictor of survival and cardiovascular risk. Along with others, we have shown an independent association between PlGF and cardiovascular events in CKD patients, but not much is known about patients receiving dialysis. METHODS: We studied 205 dialysis patients undergoing cardiac catheterization at the Nara Medical University between April 1, 2004, and December 31, 2012. Serum levels of PlGF and VEGF were measured with ELISA in all the patients. RESULTS: During a median follow-up of 20 months, 121 participants died from any cause or experienced a cardiovascular event. In the fully adjusted analysis, having an above-median PlGF or VEGF level was associated with a hazards ratio for adverse outcomes of 2.55 (1.72-3.83) and 1.39 (0.95-2.04), respectively. Using a multimarker strategy in a model with age, serum albumin, history of coronary artery disease, brain natriuretic peptide and PlGF, patients with 2, 3 and 4 positive markers had a 3.82-, 5.77- and 6.59-fold higher risk of mortality or a cardiovascular event, respectively, compared to those with no positive markers. The model with PlGF had a significantly higher c-statistic, integrated discrimination improvement index and category-free net reclassification improvement index than the model without PlGF. CONCLUSION: PlGF is independently associated with mortality and cardiovascular events, but the association between VEGF and adverse events was attenuated with covariate adjustment. The addition of PlGF to models with established clinical predictors provides additional useful prognostic information in patients receiving dialysis.

[A case report of hepatitis B virus reactivation in a hepatitis B core antibody-positive, hepatitis B surface antigen-negative hemodialysis patient].

Reactivation of the hepatitis B virus (HBV) has been reported in patients receiving immunosuppressive therapy or chemotherapy. We report a case of HBV reactivation in a patient negative for hepatitis B surface antigen (HBsAg), positive for hepatitis B core antibody (anti-HBc), and positive for hepatitis B surface antibody (anti-HBs), who was undergoing chronic maintenance hemodialysis without immunosuppressive therapy or chemotherapy. The patient was an 85-year-old woman with end-stage renal disease due to nephrosclerosis who had undergone maintenance hemodialysis for a year. She had been HBsAg-negative, anti-HBc- and anti-HBs-positive previously, but biannual routine surveillance for HBV showed positivity for HBsAg, negativity for anti-HBs, and positivity for HBV DNA (5.9 log copies/mL). She was asymptomatic, and transaminases were within normal limits. She was dialyzed in an isolated room with a dedicated staff member for the control of infection. HBV is a blood-borne pathogen, which is highly infectious. Hemodialysis is a procedure associated with high risk for blood-borne infection. We should recognize the risk of reactivation of HBV in HBsAg-negative, anti-HBc-positive patients, and consider how to incorporate anti-HBc screening and infection control in isolated anti-HBc-positive hemodialysis patients in clinical practice.

Mie-Resonant Nanophotonic-Enhancement of Asymmetry in Sodium Chlorate Chiral Crystallization.

Studies on chiral spectroscopy have recently demonstrated strong enhancement of chiral light-matter interaction in the chiral near-field of Mie resonance in high-refractive-index dielectric nanostructures by studies on chiral spectroscopy. This situation has motivated researchers to demonstrate effective chiral photosynthesis under a chiral near-field beyond circularly polarized light (CPL) as a chiral source. However, the effectivity of the chiral near-field of Mie resonance for chiral photosynthesis has not been clearly demonstrated. One major challenge is the experimental difficulty in evaluating enantiomeric excess of a trace amount of chiral products synthesized in the near-field. Here, by adopting sodium chlorate chiral crystallization as a phenomenon that includes both synthesis and the amplification of chiral products, we show that crystallization on a Mie-resonant silicon metasurface excited by CPL yields a statistically significant large crystal enantiomeric excess of ∼18%, which cannot be achieved merely by CPL. This result provides implications for efficient chiral photosynthesis in a chiral near-field.

Prevalence and Incidence of Strabismus by Age Group in Japan: A Nationwide Population-Based Cohort Study.

PURPOSE: To investigate the prevalence and incidence of strabismus in the Japanese population by age group and to estimate the subtype proportions. DESIGN: A nationwide population-based cohort study. METHODS: This study investigated the number of cases with previous and new diagnoses of strabismus by age group between 2009 and 2020 using the National Database of Health Insurance Claims and Specific Health Checkups of Japan, which includes almost all (≥95%) medical claims data. We calculated the strabismus prevalence and 1-year incidence in 2019 and analyzed the proportion of each strabismus subtype. RESULTS: The strabismus prevalence was 2.154% (2 709 207/125 708 000; 95% CI, 2.152%-2.157%). It showed a bimodal distribution, with a high proportion in school and old ages (especially ≥75 years). Exotropia, esotropia, and cyclovertical strabismus proportions were 67.3%, 26.0%, and 6.7%, respectively. Cyclovertical strabismus was uncommon in patients aged ≤18 years (1.4%) and more common (10.2%) in those aged >18 years. The strabismus incidence in 2019 was 321 per 100 000 person-years (403 093/125 708 000; 95% CI, 320-322). The annual incidence proportion of cyclovertical strabismus as opposed to whole strabismus subtypes in patients aged >18 years (13.1%) was higher than that in those aged ≤18 years (1.4%). CONCLUSIONS: This is the first nationwide population-based cohort study to demonstrate strabismus's overall prevalence and incidence. The high prevalence of cyclovertical strabismus in adults compared with children may suggest that cyclovertical strabismus is a primarily age-related strabismus. The high prevalence of exotropia may indicate a genetic difference between Japanese and other ethnicities.

A Protocol for Stepwise Differentiation of Induced Pluripotent Stem Cells into Retinal Pigment Epithelium.

We have established a stepwise method to differentiate induced pluripotent stem cells (iPSCs) into retinal pigment epithelium (RPE) (iPSC-RPE), which enables efficient isolation and purification of patient-derived iPSC-RPE cells with high quality. Here, we describe in detail the process of differentiating iPSCs into iPSC-RPE.

Choriocapillaris flow deficit in a pachychoroid spectrum disease using en face optical coherence tomography angiography averaging.

PURPOSE: To investigate the choriocapillaris changes associated with pachychoroid pigment epitheliopathy (PPE) in comparison with healthy eyes. METHODS: Nine 3 × 3 mm macular optical coherence tomography angiography images were acquired in patients with PPE and age-matched healthy participants. Multiple en face image averaging of the choriocapillaris was binarized for quantitative image analysis of the flow voids. In PPE eyes, we evaluated the presence of pachyvessels and the association between the location of the choriocapillaris flow deficit and pachyvessels. RESULTS: Thirty-two eyes with PPE and 30 eyes of healthy participants were included. In PPE eyes, the mean total area (1.16 ± 0.18 vs. 0.91 ± 0.16, p < 0.001) and average size of the flow voids (790 ± 144 vs. 520 ± 138; p < 0.001) were significantly larger than those in control eyes. Composite images of the choriocapillaris and choroid showed choriocapillaris flow deficits just above and outside the pachyvessels. The mean proportion of the flow void area overlying the pachyvessels against the whole flow void area of the choriocapillaris was 21.3% ± 10.2% (9.38%-44.42%) in PPE eyes. CONCLUSIONS: In PPE eyes, the blood flow area of the choriocapillaris decreased diffusely within the macular area compared to control eyes, and the choriocapillaris flow deficit was not necessarily related to pachyvessel location.

[Case of lead nephropathy due to chronic occupational lead exposure].

We report a case of a patient with chronic kidney disease likely due to lead nephropathy. He was a manufacturer of Buddhist altar fittings and had chronic lead exposure. The blood lead level was 41 microg/dL and urinary lead excretion at 24 hours after the administration of ethylenediaminetetraacetic acid (EDTA)was 600 microg (first time)and 687 microg (second time), respectively. Urinary lead excretion at 72 hours was 834 microg (first time) and 1,071 microg (second time), respectively. Renal biopsy showed interstitial fibrosis and focal monocyte infiltration. Lead content in the renal biopsy specimen was 130 ng/g of wet weight. We preformed weekly EDTA chelation therapy twelve times. During the therapy, serum creatinine was 1.1 mg/dL. The chelation therapy was interrupted by an episode of acute renal failure due to hypotension and heart failure. Urinary lead excretion exceeding 600 microg at 72 hours after chelation therapy indicated a lead body burden capable of causing lead nephropathy. In this case, urinary lead excretion exceeded 600 microg at 72 hours. Based on the report that repeated lead chelation therapy can slow the progression of non-diabetic chronic kidney disease with 72-hour-urinary lead excretion of 60-600 microg, we performed chelation therapy. This case suggests that lead nephropathy currently can occur in Japan. It is possible that renal dysfunction from lead nephropathy is reversed by minimizing lead exposure and chelation therapy. Lead nephropathy should be included in the differenitial diagnosis of causes of chronic kidney disease and occupational and environmental lead exposure should be investigated carefully during the medical history.

Effect of Crystal Orientation of Cu Current Collectors on Cycling Stability of Li Metal Anodes.

Li metal anodes are plagued by low coulombic efficiency due to their interfacial instability. Many approaches were proposed to cope with this problem; however, little attention has been given to the current collector of Li anodes. In this study, we investigate the crystal orientation dependence of the cycling stability of Li anodes on single-crystal Cu(111), (101), and (001) and polycrystalline Cu current collectors. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) show that (111) and (001) achieved high current efficiency and low interfacial resistance, while (101) and polycrystalline Cu exhibited low cyclabilities. X-ray photoelectron spectroscopy (XPS) and auger electron spectroscopy (AES) analysis revealed that the thickness of the solid electrolyte interphase (SEI) varies with the Cu crystal orientation, and the SEI is the thinnest on the single-crystal Cu(111). This tendency can be explained by the orientation dependence of the surface energy of Cu, which corresponds to the chemical activity of the surfaces. Our result advocates the importance of considering Cu orientation for interfacial engineering of Li metal anodes.

Characteristics of pachychoroid neovasculopathy.

Recently, several research groups have reported a newly recognized clinical entity of choroidal neovascularization, termed pachychoroid neovasculopathy. However, its characteristics have yet to be well described. The purpose of this study was to investigate the clinical and genetic characteristics of pachychoroid neovasculopathy regardless of treatment modality. This study included 99 eyes of 99 patients with treatment-naïve pachychoroid neovasculopathy. Mean initial best-corrected visual acuity (BCVA) was 0.20 ± 0.32 logMAR, and did not change (P = 0.725) during follow-up period (mean ± SD, 37.0 ± 17.6 months). Subretinal hemorrhage (SRH) (≥ 4 disc areas in size) occurred in 20 eyes (20.2%) during follow-up. Age, initial BCVA, central retinal thickness, SRH (≥ 4 disc areas in size) and treatment (aflibercept monotherapy) were significantly associated with the final BCVA (P = 0.024, < 0.001, 0.031, < 0.001, and 0.029, respectively). Multiple regression analysis showed initial BCVA and presence of SRH to be significant predictors of final BCVA (both P < 0.001). Polypoidal lesions were more common in the SRH group than in the non-SRH group (85.0% vs 48.1%, P = 0.004). There was no significant difference in the frequency of the risk allele in ARMS2 A69S, CFH I62V, CFH Y402H between these groups (P = 0.42, 0.77, and 0.85, respectively). SRH (29.1% vs 9.1%, P = 0.014) and choroidal vascular hyperpermiability (65.5% vs 43.2%, P = 0.027) were seen more frequently in the polypoidal lesion (+) group than in the polypoidal lesion (-) group. There was considerable variation in lesion size and visual function in patients with pachychoroid neovasculopathy, and initial BCVA and presence of SRH at the initial visit or during the follow-up period were significant predictors of final BCVA.

Heat-resistant DNA tile arrays constructed by template-directed photoligation through 5-carboxyvinyl-2'-deoxyuridine.

Template-directed DNA photoligation has been applied to a method to construct heat-resistant two-dimensional (2D) DNA arrays that can work as scaffolds in bottom-up assembly of functional biomolecules and nano-electronic components. DNA double-crossover AB-staggered (DXAB) tiles were covalently connected by enzyme-free template-directed photoligation, which enables a specific ligation reaction in an extremely tight space and under buffer conditions where no enzymes work efficiently. DNA nanostructures created by self-assembly of the DXAB tiles before and after photoligation have been visualized by high-resolution, tapping mode atomic force microscopy in buffer. The improvement of the heat tolerance of 2D DNA arrays was confirmed by heating and visualizing the DNA nanostructures. The heat-resistant DNA arrays may expand the potential of DNA as functional materials in biotechnology and nanotechnology.

Acute kidney injury as an independent predictor of infection and malignancy: the NARA-AKI cohort study.

BACKGROUND: Acute kidney injury (AKI) is associated with higher mortality and cardiovascular events. However, association between AKI and non-cardiac events such as infection or malignancy is largely unknown. METHODS: This is a retrospective cohort study. Inclusion criteria were adults who underwent non-cardiac surgery from 2007 to 2011 at Nara Medical University Hospital. Exclusion criteria were urological surgery, obstetric surgery, missing creatinine values peri-operatively, and pre-operative dialysis. The end of observation period was at the end of 2015 or loss to follow-up. A predictor was AKI defined by KDIGO criteria within 1-week post-operatively. Outcomes were hospitalization for infection or diagnoses of malignancy. Associations between AKI and outcomes were examined by Cox regression models. RESULTS: Among 6692 subjects, 445 (6.6%) developed AKI. During median follow-up of 4.0 years, there were 485 hospitalizations for infection and 1138 diagnoses of malignancy (2.0 and 5.1 events/100 patient-years, respectively). After adjustment for potential confounders, AKI was independently associated with hospitalization for infection and diagnoses of malignancy (Hazard ratio [95% confidence interval]: 1.64 [1.23-2.20] and 1.31 [1.06-1.61], respectively). Excluding recurrence of malignancy from outcomes and analyses limited to those who recover renal function by the time of discharge yielded similar results. Absolute lymphocyte counts were significantly lower and neutrophil-to-lymphocyte ratios were significantly higher among those with AKI. CONCLUSIONS: AKI was significantly associated with hospitalization for infection and development of malignancy during long-term follow-up. Those with AKI might be in persistent immunosuppressed state.

Efficacy of Photodynamic Therapy for Polypoidal Choroidal Vasculopathy Associated with and without Pachychoroid Phenotypes.

PURPOSE: To compare the efficacy of photodynamic therapy (PDT) in eyes with polypoidal choroidal vasculopathy (PCV) associated with and without pachychoroid phenotypes (pachychoroid PCV and nonpachychoroid PCV, respectively). DESIGN: Retrospective chart review. PARTICIPANTS: Patients previously diagnosed with PCV and initially treated with PDT. METHODS: Patients were classified as having pachychoroid- or nonpachychoroid-driven conditions. The long-term visual outcome and its associated factors were investigated. MAIN OUTCOME MEASURES: Visual acuity (VA) outcomes at 1, 2, 3, 4, and 5 years after initial PDT in pachychoroid and nonpachychoroid PCV. RESULTS: Of the 158 eyes, 88 (55.7%) met the criteria for pachychoroid PCV; 70 (44.3%) did not (nonpachychoroid PCV). In cases of pachychoroid PCV, VA improved significantly at 1 year (P = 0.042) and maintained baseline level at 5 years (P = 0.38). By contrast, VA continued to deteriorate in the nonpachychoroid PCV group during the follow-up period and had already declined significantly by the second year (P = 0.022, compared with baseline). Despite no difference in baseline VA between pachychoroid and nonpachychoroid PCV groups (P = 0.11), the VA at 5 years was significantly better in the pachychoroid PCV group compared with the nonpachychoroid PCV group (0.54±0.47 vs. 0.93±0.63, respectively; P = 0.23 × 10-3). The incidence of massive submacular hemorrhage (SMH) or vitreous hemorrhage (VH) was not different between groups at 5 years (P = 0.67), and their occurrence was associated with decreased VA in both the nonpachychoroid and pachychoroid PCV groups (coefficient ß, 0.361 and 0.481; P = 0.59 × 10-3 and P < 1.0 × 10-5, respectively). CONCLUSIONS: Five years after PDT treatment, VA was maintained at the baseline level in the pachychoroid PCV group but not in the nonpachychoroid PCV group. Massive SMH or VH during the follow-up period affected the final visual outcomes in both conditions.

A Prediction Model with Lifestyle in Addition to Previously Known Risk Factors Improves Its Predictive Ability for Cardiovascular Death.

This longitudinal cohort study aimed to create a novel prediction model for cardiovascular death with lifestyle factors. Subjects aged 40-74 years in the Japanese nationwide Specific Health Checkup Database in 2008 were included. Subjects were randomly assigned to the derivation and validation cohorts by a 2:1 ratio. Points for the prediction model were determined using regression coefficients that were derived from the Cox proportional hazards model in the derivation cohort. Models 1 and 2 were developed using known risk factors and known factors with lifestyle factors, respectively. The models were validated by comparing Kaplan-Meier curves between the derivation and validation cohorts, and by calibration plots in the validation cohort. Among 295,297 subjects, data for 120,823 were available. There were 310 cardiovascular deaths during a mean follow-up of 3.6 years. Model 1 included known risk factors. In model 2, weight gain, exercise habit, gait speed, and drinking alcohol were additionally included as protective factors. Kaplan-Meier curves matched better between the derivation and validation cohorts in model 2, and model 2 was better calibrated. In conclusion, our prediction model with lifestyle factors improved the predictive ability for cardiovascular death.

Higher dialysate calcium concentration is associated with incident myocardial infarction among diabetic patients with low bone turnover: a longitudinal study.

This is a longitudinal study on 53,560 hemodialysis patients from the Japan Renal Data Registry. Predictor was D[Ca] ≥3.0 vs 2.5 mEq/L. Outcomes were the first CV events during 1-year observation period. Association of D[Ca] with CV events and effect modifications were tested using multivariate logistic regression analyses. Diabetes mellitus (DM) was a significant effect modifier for association of higher D[Ca] and myocardial infarction (MI) (OR: 1.26 (1.03-1.55) among DM and 0.86 (0.72-1.03) among non-DM, p for interaction <0.01). The effect size was not affected by further adjustment for serum albumin-corrected Ca or intact parathyroid hormone (iPTH) levels, but was attenuated by adjustment for intradialytic change in serum Ca concentration (ΔCa) (1.16 [0.89-1.51]). Among DM, D[Ca] ≥3.0 mEq/L was significantly associated with MI in the first tertile of corrected Ca or iPTH ≤60 pg/ml (p for interaction 0.03 and 0.03, respectively). In conclusion, higher D[Ca] was associated with incident MI in DM, especially with low serum Ca or iPTH levels. Attenuation of the effect size by adjustment for ΔCa and stratified analyses suggest that larger Ca influx during dialysis with higher D[Ca] in patients suggestive of low bone turnover leads to vascular calcification and subsequent MI in DM.

Author Correction: Higher dialysate calcium concentration is associated with incident myocardial infarction among diabetic patients with low bone turnover: a longitudinal study.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Acute kidney injury in a postpartum woman with paroxysmal nocturnal hemoglobinuria: A case report and literature review.

Paroxysmal nocturnal hemoglobinuria is a rare clonal hematopoietic stem cell disorder characterized by intravascular hemolysis, hemoglobinuria, and inflammatory thrombotic state. Intravascular hemolysis in paroxysmal nocturnal hemoglobinuria (PNH) can lead to acute and chronic renal injury through hemoglobin-mediated toxicity. A 32-year-old pregnant woman with myelodysplastic syndrome was admitted to our hospital with severe preeclampsia. Shortly after an urgent caesarean section, she became obtunded and showed signs of acute kidney injury (AKI) with anuria, severe intravascular hemolysis, and hypermagnesemia. She was diagnosed with PNH with a positive Ham test and flow cytometry analysis. Renal magnetic resonance imaging revealed decreased signal intensity in the renal cortex due to hemosiderin deposition. Hemodialysis, plasma exchange, and administration of corticosteroids ameliorated her clinical condition and renal function. This case illustrates that careful management is required to prevent postpartum AKI in pregnant women with PNH.

Development of angle-resolved spectroscopy system of electrons emitted from a surface with negative electron affinity state.

We developed an angle-resolved photoemission spectroscopy system for the analysis of conduction-band electrons. By forming a negative electron affinity surface on a semiconductor surface, electrons in conduction bands are emitted into a vacuum and measured by using an analyzer. This method enables us to determine the energy and momentum of the conduction electrons. Furthermore, it can be used to determine unoccupied conduction band structures. The main challenges of this method are that the energies of the emitted electrons are extremely low and the trajectories of the electrons change due to various influences. We overcame these problems by placing the shielding mesh close to the sample and parallel to the sample surface. The entire chambers, including the shielding mesh, were grounded, and a negative bias voltage was applied only to the sample. This configuration realizes the acceleration of electrons while preserving the momentum component parallel to the sample surface. Another problem is the establishment of a method for converting a detected angle into the corresponding wavevector. We focused on the emission angle of electrons emitted from a sample and their minimum energy and then established an analytical method for converting detected angles into corresponding wavevectors on the basis of the minimum energy.