Functional identification of specialized diterpene synthases from Chamaecyparis obtusa and C. obtusa var. formosana to illustrate the putative evolution of diterpene synthases in Cupressaceae.

Chamaecyparis obtusa and C. obtusa var. formosana of the Cupressaceae family are well known for their fragrance and excellent physical properties. To investigate the biosynthesis of unique diterpenoid compounds, diterpene synthase genes for specialized metabolite synthesis were cloned from C. obtusa and C. obtusa var. formosana. Using an Escherichia coli co-expression system, eight diterpene synthases (diTPSs) were characterized. CoCPS and CovfCPS are class II monofunctional (+)-copalyl diphosphate synthases [(+)-CPSs]. Class I monofunctional CoLS and CovfLS convert (+)-copalyl diphosphate [(+)-CPP] to levopimaradiene, CoBRS, CovfBRS1, and CovfBRS3 convert (+)-CPP to (-)-beyerene, and CovfSDS converts (+)-CPP to (-)-sandaracopimaradiene. These enzymes are all monofunctional diterpene syntheses in Cupressaceae family of gymnosperm, and differ from those in Pinaceae. The discovery of the enzyme responsible for the biosynthesis of tetracyclic diterpene (-)-beyerene was characterized for the first time. Diterpene synthases with different catalytic functions exist in closely related species within the Cupressaceae family, indicating that this group of monofunctional diterpene synthases is particularly prone to the evolution of new functions and development of species-specific specialized diterpenoid constituents.

Gas exchange and chlorophyll fluorescence responses of Camellia sinensis grown under various cultivations in different seasons.

Sod culture (SC) and conventional agriculture (CA) represent two distinct field management approaches utilized in the cultivation of tea plants in Taiwan. In this study, we employed gas exchange and chlorophyll fluorescence techniques to assess the impact of SC and CA methods on the photosynthetic machinery of Camellia sinensis cv. TTES No.12 (Jhinhsuan) in response to variable light intensities across different seasons. In spring, at photosynthetic photon flux densities (PPFD) ranging from 800 to 2,000 µmol photon m-2 s-1, the net photosynthesis rate (Pn, 10.43 µmol CO2 m-2 s-1), stomatal conductance (Gs, 126.11 mmol H2O m-2 s-1), electron transport rate (ETR, 137.94), and ΔF/Fm' and Fv/Fm (50.37) values for plants grown using SC were comparatively higher than those cultivated under CA. Conversely, the non-photochemical quenching (NPQ) values for SC-grown plants were relatively lower (3.11) compared to those grown under CA at 800 to 2,000 PPFD in spring. Additionally, when tea plants were exposed to PPFD levels below 1,500 µmol photon m- 2 s- 1, there was a concurrent increase in Pn, Gs, ETR, and NPQ. These photosynthetic parameters are crucial for devising models that optimize cultivation practices across varying seasons and specific tillage requirements, and for predicting photosynthetic and respiratory responses of tea plants to seasonally or artificially altered light irradiances. The observed positive impacts of SC on maximum photosynthetic rate (Amax), Fv/Fm, Gs, water-use efficiency (WUE), and ETR suggest that SC is advantageous for enhancing the productivity of tea plants, thereby offering a more adaptable management model for tea gardens.

Exchange interaction for the triplet superconductor UTe2.

UTe2 is one triplet superconductor that defies conventional relation between ferromagnetism and superconductivity. Our search for a theoretical explanation starts with one spin-triplet state of two electrons and construct a two-particle exchange interaction that favors the formation of Cooper pairs under the configuration. A modified application of the Bardeen-Cooper-Schrieffer (BCS) theory using parameters derived from ab-initio density functional calculations for electrons and phonons enables us to derive the critical temperature of 1.64 K and an average superconducting gap of 0.25 meV at 0 K. We extend the investigation further into the superconductivity under pressure, showing how Tc and the gap of UTe2 change under compression in ways that are consistent with the results of experiment.

The influence of early adoption of nonenhanced computed tomography on management of patients with pyogenic liver abscess.

Background and Aim: A pyogenic liver abscess (PLA) is an infectious disease with high in-hospital mortality. It has no specific symptoms and is difficult to be diagnosed early in the emergency department. Ultrasound is commonly used to detect PLA lesions of PLA, but its sensitivity can be affected by lesion size, location, and clinician experience. Therefore, early diagnosis and prompt treatment (especially abscess drainage) are crucial for better patient outcomes and should be prioritized by clinical physicians. Methods: We conducted a retrospective study to compare the effect of early and late (i.e., receiving CT scanning within 48 h and >48 h after admission) adoption of nonenhanced computed tomography (CT) scanning regarding the hospitalization days and interval between admission and drainage of patients with PLA. Results: This study included 76 hospitalized patients with PLA in the Department of Digestive Disease of Xiamen Chang Gung Hospital in China who underwent CT examinations from 2014 to 2021. We conducted CT scans on 56 patients within 48 h of admission and on 20 patients more than 48 h after admission. The early CT group had a significantly shorter hospitalization length compared with the late CT group (15.0 days vs. 20.5 days; P = 0.035). Besides, the median time to initiate drainage after admission was also significantly shorter in the early CT group than in the late CT group (1.0 days vs. 4.5 days; P < 0.001). Conclusion: Early CT scanning within 48 h of admission may aid in early PLA diagnosis and benefit disease recovery, as revealed by our findings.

Intestinal fatty acid-binding protein is a biomarker for diagnosis of biliary tract infection.

BACKGROUND AND AIM: Biliary tract infection (BTI) is an inflammatory disease and commonly associated with bacteremia. Delays in diagnosis or treatment of BTI cause high morbidity and mortality. However, an early diagnosis depends on appropriate clinical investigations. Appropriate biomarkers are urgently needed to improve the BTI diagnostic rate. We hypothesized that intestinal fatty acid-binding protein (I-FABP) might be a potential biomarker for BTI diagnosis. METHODS: We examined data from subjects aged ≥18 years diagnosed with BTI, including cholangitis and cholecystitis, whose blood samples were adequate for I-FABP and zonulin assessment. We also collected blood samples from healthy volunteers as the control group. We excluded subjects in both groups who received steroids, antibiotics, or probiotics within 1 month before hospital admission (BTI cohort) or participation in this research (controls). The main study endpoint was to compare the diagnostic ability of I-FABP to detect BTI in comparison with high-sensitivity C-reactive protein (hs-CRP) and zonulin. RESULTS: The study collected the data of 51 patients with BTI and 35 healthy subjects. The receiver operating characteristic (ROC) area under the curve (AUC) for I-FABP was 0.884 (95% confidence interval [CI]: 0.814-0.954), numerically higher than that for hs-CRP (0.880; 0.785-0.976) and zonulin (0.570; 0.444-0.697). We estimated that the optimal cutoff value of I-FABP was 2.1 ng/mL (sensitivity: 0.804; specificity: 0.829) for the diagnosis of BTI. CONCLUSIONS: In summary, this study suggests that I-FABP may be a potential alternative biomarker to hs-CRP for diagnosing BTI. Further research should verify the use of I-FABP as a marker for BTI diagnosis, but also for other inflammatory diseases.

Electronic structures of WS2 armchair nanoribbons doped with transition metals.

Armchair WS2 nanoribbons are semiconductors with band gaps close to 0.5 eV. If some of the W atoms in the ribbon are replaced by transition metals, the impurity states can tremendously affect the overall electronic structure of the doped ribbon. By using first-principles calculations based on density functional theory, we investigated substitutional doping of Ti, V, Cr, Mn, Fe, and Co at various positions on WS2 ribbons of different widths. We found that Fe-doped ribbons can have two-channel conduction in the middle segment of the ribbon and at the edges, carrying opposite spins separately. Many Co-doped ribbons are transformed into spin filters that exhibit 100% spin-polarized conduction. These results will be useful for spintronics and nanoelectronic circuit design.

Low-Grade Myofibroblastic Sarcoma Arising From Keloid Scar on the Chest Wall After Thoracic Surgery.

Keloids are considered as benign fibroproliferative skin tumors, and rare cases of malignancies have been reported. We present a case of low-grade myofibroblastic sarcoma arising from a recurrent painful keloid scar on the right chest wall after video-assisted thoracic surgery for pneumothorax in a 77-year-old man. Wide composite excision of the keloid, surrounding ribs, and partial diaphragm were performed. The chest wall pleural defect was reconstructed with Teflon (Chemours, Wilmington, DE), and soft tissue was reconstructed with a transverse rectus abdominis myocutaneous flap. This case highlights that refractory keloids may be considered a harbinger of malignancy.

Association between risk factors of metabolic syndrome with lung function.

BACKGROUND/OBJECTIVES: Increased evidence suggests that metabolic syndrome (MetS) is correlated with lung function impairment. This study aimed to explore the associations between MetS risk factors and the lung function. SUBJECTS/METHODS: The cross-sectional study included 6945 participants attending health examination between 2010 and 2012 in Taiwan. MetS was assessed according to the criteria of National Cholesterol Education Program III. Spirometric parameters were measured to define lung function. The relationships were tested using multiple linear regression and logistic regression analyses. RESULTS: The prevalence of MetS was significantly higher in males (16.2%) than females (3.8%). Although the prevalence of restrictive lung disease (RLD) was comparable between genders (20.7 and 21.0%), males with co-existent MetS had a higher prevalence of RLD than females (27.4 vs. 18.0%). Abdominal obesity, indicated by waist circumference (WC) and weight-to-height ratio (WHtR), was the most significant factor associated with lung function decline. Other components of MetS also showed statistically significant relationships, but very weak, with lung function. There was a trend toward an increased prevalence of RLD with the increasing number of MetS scores in males, independent of age, smoking, and body mass index. CONCLUSIONS: Abdominal obesity was the key component of MetS associated with mechanical effect on lung function impairment in a prime-age adult population. Although RLD was not associated with increased probability of having MetS, the participants with more MetS scores were at a higher risk of losing lung function.

Distinctive Signatures of the Spin- and Momentum-Forbidden Dark Exciton States in the Photoluminescence of Strained WSe2 Monolayers under Thermalization.

With both spin and valley degrees of freedom, the low-lying excitonic spectra of photoexcited transition-metal dichalcogenide monolayers (TMDC-MLs) are featured by rich fine structures, comprising the intravalley bright exciton states as well as various intra- and intervalley dark ones. The latter states can be classified as those of the spin- and momentum-forbidden dark excitons according to the violated optical selection rules. Because of their optical invisibility, these two types of the dark states are in principle hardly observed and even distinguished in conventional spectroscopies although their impacts on the optical and dynamical properties of TMDC-MLs have been well noticed. In this Letter, we present a theoretical and computational investigation of the exciton fine structures and the temperature-dependent photoluminescence spectra of strained tungsten diselenide monolayers (WSe2-MLs) where the intravalley spin-forbidden dark exciton lies in the lowest exciton states and other momentum-forbidden states are in the higher energies that are tunable by external stress. The numerical computations are carried out by solving the Bethe-Salpeter equation for an exciton in a WSe2-ML under the stress-control in the tight-binding scheme established from the first principle computation in the density functional theory. According to the numerical computation and supportive model analysis, we reveal the distinctive signatures of the spin- and momentum-forbidden exciton states of strained WSe2-MLs in the temperature-dependent photoluminescences and present the guiding principle to infer the relative energetic locations of the two types of dark excitons.

Nuclear and chloroplast DNA phylogeography suggests an Early Miocene southward expansion of Lithocarpus (Fagaceae) on the Asian continent and islands.

BACKGROUND: Most genera of Fagaceae are thought to have originated in the temperate regions except for the genus Lithocarpus, the stone oaks. Lithocarpus is distributed in subtropical and tropical Asia, and its ancestral population is hypothesized to be distributed in tropical regions in Borneo and Indochina. Borneo and the nearby islands (the Greater Sunda Islands) were connected to the Malay Peninsula and Indochina prior to the Pliocene epoch and formed the former Sundaland continent. The Southeast Asian Lithocarpus, is thought to have dispersed between continental Asia and the present Sundaland. The drastic climate changes during the Pliocene and Pleistocene epochs which caused periodic sea-level changes is often used to explain the cause of its diversity. The aim of this study was to establish phylogenetic relationships by analyzing nuclear (nrDNA) and chloroplast (cpDNA) DNA in order to describe and analyze the origin, causes of diversification and historical biogeography of Lithocarpus. RESULTS: Phylogeny reconstructed through the multiple-species coalescent method with nrDNA and cpDNA revealed that the continental-Asian taxa were clustered at the basal lineages. The derived lineages of tropical Lithocarpus, with the inference of a subtropical ancestral state, imply a southward migration in the Early Miocene period with subsequent in situ diversification in the Greater Sunda Islands. The gradual decrease in temperature since the Middle Miocene period is proposed as a cause of the increase in the net diversification rate. CONCLUSIONS: The historical ancestral origin of Lithocarpus has been suggested to be mainland Asia. Southward migration in the Early Miocene period with subsequent in situ diversification could explain the current diversity of stone oaks in Southeast Asia. This study also considered the multiple origins of stone oaks currently indigenous to the subtropical islands offshore and near mainland China. Our results provide phylogenetic evidence for a subtropical origin of Asian stone oaks and reveal the process of diversification and how it fits into the timeline of major geologic and climatic events rather than local, episodic, rate-shifting events.

Molecular genetic and biochemical evidence for adaptive evolution of leaf abaxial epicuticular wax crystals in the genus Lithocarpus (Fagaceae).

BACKGROUND: Leaf epicuticular wax is an important functional trait for physiological regulation and pathogen defense. This study tests how selective pressure may have forced the trait of leaf abaxial epicuticular wax crystals (LAEWC) and whether the presence/absence of LAEWC is associated with other ecophysiological traits. Scanning Electron Microscopy was conducted to check for LAEWC in different Lithocarpus species. Four wax biosynthesis related genes, including two wax backbone genes ECERIFERUM 1 (CER1) and CER3, one regulatory gene CER7 and one transport gene CER5, were cloned and sequenced. Ecophysiological measurements of secondary metabolites, photosynthesis, water usage efficiency, and nutrition indices were also determined. Evolutionary hypotheses of leaf wax character transition associated with the evolution of those ecophysiological traits as well as species evolution were tested by maximum likelihood. RESULTS: Eight of 14 studied Lithocarpus species have obvious LAEWC appearing with various types of trichomes. Measurements of ecophysiological traits show no direct correlations with the presence/absence of LAEWC. However, the content of phenolic acids is significantly associated with the gene evolution of the wax biosynthetic backbone gene CER1, which was detected to be positively selected when LAEWC was gained during the late-Miocene-to-Pliocene period. CONCLUSIONS: Changes of landmass and vegetation type accelerated the diversification of tropical and subtropical forest trees and certain herbivores during the late Miocene. As phenolic acids were long thought to be associated with defense against herbivories, co-occurrence of LAEWC and phenolic acids may suggest that LAEWC might be an adaptive defensive mechanism in Lithocarpus.

Armchair MoS2 nanoribbons turned into half metals through deposition of transition-metal and Si atomic chains.

MoS2 nanoribbons with armchair-terminated edges are semiconductors suitable for the tuning of electronic and magnetic properties. Our first-principles density function calculations reveal that a variety of transition-metal atomic chains deposited on some of the ribbons is able to transform the semiconductors into half metals, allowing transport of 100% spin-polarized currents. Furthermore, we found that a Si atomic chain is equally capable of achieving half metallicity when adsorbed on the same nanoribbon. These results should be useful for spintronic application.

Integrating ecosystem services in terrestrial conservation planning.

The purpose of this study is to estimate the benefits of ecosystem services for prioritization of land use conservation and to highlight the importance of ecosystem services by comparison between ecosystem service value and green GDP accounting. Based on land use pattern and benefit transfer method, this research estimated value of ecosystem services in Taiwan. Scientific information of land use and land cover change is accessed through multi-year satellite imagery moderate resolution imaging spectroradiometer (MODIS), and geographic information system (GIS) technology. Combined with benefit transfer method, this research estimated the ecosystem service valuation of forest, grassland, cropland, wetland, water, and urban for the period of 2000 to 2015 in Taiwan. It is found that forest made the greatest contribution and the significant increasing area of wetland has huge potential benefit for environmental conservation in Taiwan. We recommend placing maintaining wetland ecosystem in Taiwan with higher priority. This research also compared ecosystem service value with natural capital consumption which would essentially facilitate policy makers to understand the relationship between benefits gained from natural capital and the loss from human-made capital.

All Components of Metabolic Syndrome Are Associated with Microalbuminuria in a Chinese Population.

BACKGROUND AND AIM: Albuminuria is a well-known predictor of poor renal and cardiovascular outcomes and associated with increased risk of all-cause mortality. The study aimed to evaluate the associations between metabolic characteristics and the presence of albuminuria. METHODS: This cross-sectional study included 18,384 adult Chinese who participated in health examinations during 2013-2014. Differences in clinical characteristics were compared for microalbuminuria (MAU) and albuminuria, and between genders. Potential risk factors associated with the risk of developing MAU and albuminuria were analyzed using univariate logistic regression. Multiple logistic regression was applied to further identify the independent associations between different levels of risk factors and the presence of MAU and albuminuria. The area under the ROC curve (AUC) was used to determine the discriminatory ability of metabolic risk factors in detecting albuminuria. RESULTS: There were significant gender differences in clinical characteristics according to albuminuria status. Risk for the presence of albuminuria was significantly associated with age, male gender, waist circumference (WC), waist-to-height ratio (WHtR), hypertension, fasting plasma glucose (FPG), and triglycerides to high-density lipoprotein cholesterol ratio (TG/HDL-C) in univariate logistic regression. Multiple logistic regression analysis indicated that the factors significantly associated with the presence of MAU were WC > 90cm, WHtR at 0.6-0.7, hypertension, FPG > 6.1 mmole/L, and TG/HDL-C ratio > 1.6. The optimal cutoffs for risk factors of metabolic syndrome (MetS) to predict albuminuria in males and females were: WC, 90.8 vs. 80.0 cm; WHtR, 0.53 vs. 0.52; MAP, 97.9 vs. 91.9 mmHg; FPG, 5.40 vs. 5.28 mmole/L; and TG/HDL-C, 1.13 vs. 1.08. CONCLUSION: MetS and all its components were associated with the presence of MAU in a health check-up population in China. Gender specific and optimal cutoffs for MetS components associated with the presence of MAU were determined.

Electronic Structures of Clusters of Hydrogen Vacancies on Graphene.

Hydrogen vacancies in graphane are products of incomplete hydrogenation of graphene. The missing H atoms can alter the electronic structure of graphane and therefore tune the electronic, magnetic, and optical properties of the composite. We systematically studied a variety of well-separated clusters of hydrogen vacancies in graphane, including the geometrical shapes of triangles, parallelograms, hexagons, and rectangles, by first-principles density functional calculation. The results indicate that energy levels caused by the missing H are generated in the broad band gap of pure graphane. All triangular clusters of H vacancies are magnetic, the larger the triangle the higher the magnetic moment. The defect levels introduced by the missing H in triangular and parallelogram clusters are spin-polarized and can find application in optical transition. Parallelograms and open-ended rectangles are antiferromagnetic and can be used for nanoscale registration of digital information.

The importance of associations with saprotrophic non-Rhizoctonia fungi among fully mycoheterotrophic orchids is currently under-estimated: novel evidence from sub-tropical Asia.

BACKGROUND AND AIMS: Most fully mycoheterotrophic (MH) orchids investigated to date are mycorrhizal with fungi that simultaneously form ectomycorrhizas with forest trees. Only a few MH orchids are currently known to be mycorrhizal with saprotrophic, mostly wood-decomposing, fungi instead of ectomycorrhizal fungi. This study provides evidence that the importance of associations between MH orchids and saprotrophic non-Rhizoctonia fungi is currently under-estimated. METHODS: Using microscopic techniques and molecular approaches, mycorrhizal fungi were localized and identified for seven MH orchid species from four genera and two subfamilies, Vanilloideae and Epidendroideae, growing in four humid and warm sub-tropical forests in Taiwan. Carbon and nitrogen stable isotope natural abundances of MH orchids and autotrophic reference plants were used in order to elucidate the nutritional resources utilized by the orchids. KEY RESULTS: Six out of the seven MH orchid species were mycorrhizal with either wood- or litter-decaying saprotrophic fungi. Only one orchid species was associated with ectomycorrhizal fungi. Stable isotope abundance patterns showed significant distinctions between orchids mycorrhizal with the three groups of fungal hosts. CONCLUSIONS: Mycoheterotrophic orchids utilizing saprotrophic non-Rhizoctonia fungi as a carbon and nutrient source are clearly more frequent than hitherto assumed. On the basis of this kind of nutrition, orchids can thrive in deeply shaded, light-limiting forest understoreys even without support from ectomycorrhizal fungi. Sub-tropical East Asia appears to be a hotspot for orchids mycorrhizal with saprotrophic non-Rhizoctonia fungi.

The seed development of a mycoheterotrophic orchid, Cyrtosia javanica Blume.

BACKGROUND: Cyrtosia javanica is a rare, mycoheterotrophic vanilloid orchid native to the bamboo forest in central Taiwan. Like some vanilloid orchids, the seeds of C. javanica are hard and difficult to germinate in vitro. A better understanding of the embryology would provide insights in the propagation and conservation of this rare species. RESULTS: Based on the histological and histochemical studies, we observed some remarkable features in developing seeds of C. javanica. First, the developing embryos without a structurally defined suspensor; Second, the chalazal accessory cells have densely stained cytoplasms that are different from the adjacent cells of seed coat; Third, the multiple layers of seed coat with the lignified in the outermost cell layer of the outer seed coat. CONCLUSIONS: In C. javanica, the large and heavy seeds embedded in fresh fruits may adapt to the dispersal strategy. The hard seeds with lignified outer seed coat could provide a rigid protection during seed dispersal but also cause coat-imposed dormancy. This study provides insights in the seed coat structure and the hints of seed treatment methods.

High-temperature isothermal chemical cycling for solar-driven fuel production.

The possibility of producing chemical fuel (hydrogen) from the solar-thermal energy input using an isothermal cycling strategy is explored. The canonical thermochemical reactive oxide, ceria, is reduced under high temperature and inert sweep gas, and in the second step oxidized by H2O at the same temperature. The process takes advantage of the oxygen chemical potential difference between the inert sweep gas and high-temperature steam, the latter becoming more oxidizing with increasing temperature as a result of thermolysis. The isothermal operation relieves the need to achieve high solid-state heat recovery for high system efficiency, as is required in a conventional two-temperature process. Thermodynamic analysis underscores the importance of gas-phase heat recovery in the isothermal approach and suggests that attractive efficiencies may be practically achievable on the system level. However, with ceria as the reactive oxide, the isothermal approach is not viable at temperatures much below 1400 °C irrespective of heat recovery. Experimental investigations show that an isothermal cycle performed at 1500 °C can yield fuel at a rate of ~9.2 ml g(-1) h(-1), while providing exceptional system simplification relative to two-temperature cycling.

Unusual decrease in conductivity upon hydration in acceptor doped, microcrystalline ceria.

The impact of hydration on the transport properties of microcrystalline Sm(0.15)Ce(0.85)O(1.925) has been examined. Dense, polycrystalline samples were obtained by conventional ceramic processing and the grain boundary regions were found, by high resolution transmission electron microscopy, to be free of impurity phases. Impedance spectroscopy measurements were performed over the temperature range 250 to 650 °C under dry, H(2)O-saturated, and D(2)O-saturated synthetic air; and over the temperature range 575 to 650 °C under H(2)-H(2)O atmospheres. Under oxidizing conditions humidification by either H(2)O or D(2)O caused a substantial increase in the grain boundary resistivity, while leaving the bulk (or grain interior) properties unchanged. This unusual behavior, which was found to be both reversible and reproducible, is interpreted in terms of the space-charge model, which adequately explains all the features of the measured data. It is found that the space-charge potential increases by 5-7 mV under humidification, in turn, exacerbating oxygen vacancy depletion in the space-charge regions and leading to the observed reduction in grain boundary conductivity. It is proposed that the heightened space-charge potential reflects a change in the relative energetics of vacancy creation in the bulk and at the grain boundary interfaces as a result of water uptake into the grain boundary core. Negligible bulk water uptake is detected under both oxidizing and reducing conditions.

Structural and electronic properties of graphene nanotube-nanoribbon hybrids.

The structural and electronic properties of a hybrid of an armchair graphene nanotube and a zigzag graphene nanoribbon are investigated by first-principles spin-polarized calculations. These properties strongly depend either on the nanotube location or on the spin orientation. The interlayer spacing, the transverse distance from the center of the ribbon and the stacking configuration affect the electronic structures. The antiferromagnetic configuration has a lower total energy than the ferromagnetic one. The interlayer atomic interactions between the two subsystems would change the low energy dispersions, open subband spacings, and induce more band-edge states. Moreover, such interactions create an energy gap and break the spin degeneracy in the antiferromagnetic configuration. The band-edge-state energies are sensitive to the nanotube location.