Camchaya bolavenensis (Asteraceae: Vernonieae), a new species from Bolaven Plateau, southern Laos

A new species Camchaya bolavenensis (Asteraceae: Vernonieae: Centrapalinae) from Dong Hua Sao National Protected Area located in Bolaven Plateau, southern Laos, is described and illustrated. It resembles C. gracilis and C. thailandica in morphology but distinguished by its basally decumbent stem, margin of lamina with distinct (1–)2–3 teeth, 2–4 mm long on each side, invisible secondary veins, and a capitulum with 10–30 of florets

Surface strain at the cervical area and fracture strength of flared root canals reinforced using a zirconia tube and glass-fiber post

Background/purpose: Recently, an effective core build-up system for teeth with flared root canals is needed. This research aimed to evaluate the effect of foundation restorations using a composite resin core with a fiber post reinforced with a zirconia tube for the surface strain at the cervical area and the fracture load of teeth with flared root canals. Materials and methods: Bovine teeth were shaped to mimic human premolars with flared root canals and restored using three types of composite resin foundation restorations with each materials described below: a fiber post (FC), a zirconia tube (ZC), a fiber post and zirconia tube (ZFC). Each specimen was restored with a zirconia crown. The surface strains of the specimens at the cervical area and fracture loads were analyzed using a one-way analysis of variance (ANOVA), followed by Tukey's honest significant difference test. Results: The surface strains of Groups ZFC and ZC were significantly lower than that of Group FC in the buccal root. The fracture strengths of Groups ZFC and ZC were significantly higher than that of Group FC. The strength of Group ZFC was significantly higher than that of Group ZC. Conclusion: The use of a composite resin core with a zirconia tube for the simulated premolar with flared root canals reduced surface strain at the cervical area and provided higher fracture strength compared to using a composite resin core with a fiber post. And the zirconia tubes provided even higher fracture strength when used with a fiber post

Camchaya bolavenensis Noyori, Komada, Soulad. & Tagane 2022, sp. nov.

Camchaya bolavenensis Noyori, Komada, Soulad. & Tagane, sp. nov. Figs 1–3. Diagnosis: — Camchaya bolavenensis is morphologically similar to C. thailandica Bunwong et al. (2012: 53) of Thailand and C. gracilis of Thailand and Laos in the point that all of them have terminal and axillary capitulescences and phyllaries without marginal spines. However, C. bolavenensis is distinguished from these two by its basally decumbent stem (vs. entirely erect), margin of lamina with distinct (1–)2–3 teeth which is 2–4 mm long (vs. entire or serrate with 5–10 teeth less than 1 mm long), invisible secondary veins (vs. prominent and clearly visible abaxially), and 10–30 florets per capitulescence (vs. 50–70 florets). Type:— LAOS. Champasak Province, Paksong District, near Nong Luang Village, Dong Hua Sao National Protected Area (Bolaven Plateau), 15°03′43.35″N, 106°12′37.47″E, 1252 m elev., 17 Dec. 2019, Souladeth P ., Tagane S., Kongxaysavath D., Rueangruea S., Suddee S., Suyama Y., Suzuki E. L3349 (holotype FOF [FOF0005197!], isotypes BKF, KAG [KAG155714!]). Herbs, probably perennial, up to 50 cm tall. Stem decumbent at lower part, erect in middle and upper part, terete, inconspicuously ribbed, sparsely covered with short filiform hairs and glands, 1–2 mm in diam. Leaves alternate, sessile; blades narrowly obovate to linear, 3.5–6.2 × 0.4–1 cm, apex acuminate, base cuneate to attenuate, margin serrate with (1–)2–3 teeth, 2–4 mm long on each side, chartaceous, gray-green adaxially, pale greenish gray abaxially, glabrous on both surfaces except a few filiform hairs on margin near lamina base, very sparsely covered with capitate glands on both surfaces, midrib slightly prominent abaxially, secondary and tertiary veins invisible. Capitulescences terminal and axillary, solitary or corymbose. Capitula pedunculate, 1.3–1.5 cm long in anthesis, involucres campanulate, 3–5 mm in diam. Receptacle convex, ca. 4 mm in diam, glabrous, with sessile glands. Phyllaries 3–4 seriate, imbricate, dull gray-green with reddish purple apices, glabrous adaxially, very sparsely hairy, glandular abaxially, margins entire, sparsely ciliolate, apex acuminate, the outer phyllaries ovate-lanceolate, 6 × 2.2 mm, the middle ones ovate-elliptic, 7.5–7.8 × 3–3.2 mm, the inner ones lanceolate, 8–9 × 1.5–2 mm long. Florets 10–30; corollas infundibular, purple, sparsely hairy, tubes 4–6 mm long, whitish, lobes 5, 3– 4 mm long, apex obtuse to slightly capitate with dense glands. Stamens 5, ca. 6 mm long, anthers linear, 1.7–2 mm long, apex acute, base sagittate, apical appendage ovate, ca. 0.4 mm long, filaments ca. 4.6 mm long, glabrous, connate to corolla near the corolla mouth, free part 1–1.1 mm long. Styles linear, 8–9 mm long, purple, pubescent, stigmas 2-branched, branches 2–2.5 mm long, ovary elliptic, 1.1–1.2 × 0.3–0.4 mm, without carpopodium. Achenes obovate-turbinate, ca. 2.2 mm long, 10-ribbed. Pappus absent. Pollen echinolophate, 6-porate, without micropuncta. Etymology: —The specific epithet bolavenensis refers to the type locality, Bolaven Plateau. Distribution: — Laos (Champassak Province, Bolaven Plateau). Additional specimens examined: — LAOS. Champasak Province, Paksong District, near Nong Luang Village, Dong Hua Sao National Protected Area (Bolaven Plateau), 15°04′19.26″N, 106°12′38.67″E, 1248 m elev., 10 Dec. 2018, Tagane S ., Nagahama A., Souladeth P., Pisuttimarn P. L2011 (FOF, KAG [KAG128113], KYO); ibid., 15°04′14.58″N, 106°12′33.72″E, 1246 m elev., 17 Dec. 2019, Souladeth P ., Tagane S., Kongxaysavath D., Rueangruea S., Suddee S., Suyama Y., Suzuki E. L3321 (BKF, FOF, KAG [KAG155686]). Habitat and ecology: — Camchaya bolavenensis grows on wet thin soil over large and exposed sandstone boulders, where it grows with sphagnum moss (Sphagnum sp.), Canscora andrographioides Griff. ex Clarke (1875: 431), Eriocaulon cormosum Souladeth et al. (2020: 2), Eriocaulon sp. and some species of Poaceae. Flowering specimens were collected in December. Vernacular name: —Mouk Nong Luang (ມ̥ƊmŊƱǥmOວǥ), suggested here. Preliminary conservation status: —Critically Endangered (CR). Camchaya bolavenensis is known only from the two populations on the plateau of Bolaven, which located within the protected area of the Dong Hua Sao National Protected Area. We observed each population less than 100 flowering stalks and they are possibly consisted of a few genets. The extent of occurrence (EOO) regarded as open rocky grassland on the plateau is less than 500 km ² and the area of occupancy (AOO) for this species is 4 km ² (using 2 km cell width). Considering these information as well as the area is popular with tourists, which might increase disturbance in the area and which could affect the survival of this species, and the vicinities are heavily affected by habitat loss due to land conversion to agriculture, mining and dams (Delang et al. 2013), a preliminary conservation status can be assessed as Critically Endangered according to the IUCN criteria 2ab(iii) (IUCN Standards and Petitions Committee 2019). Notes: —In addition to Camchaya gracilis, C. bolavenensis is different from C. loloana, another species of the genus distributed in Laos, in having basally decumbent stem (vs. erect in C. loloana), glabrous leaves (vs. covered with whip-shaped hairs), and entire phyllaries (vs. with spines).Published as part of Noyori, Wataru, Komada, Natsuki, Souladeth, Phetlasy & Tagane, Shuichiro, 2022, Camchaya bolavenensis (Asteraceae: Vernonieae), a new species from Bolaven Plateau, southern Laos, pp. 1-6 in Phytotaxa 536 (1) on pages 2-6, DOI: 10.11646/phytotaxa.536.1.1, http://zenodo.org/record/622423

Effects of immersion in 4-methacryloyloxyethyl trimellitate anhydride/methyl methacrylate-tri-n-butyl borane resin-activated liquid on microtensile bond strength of root canal dentin

Background/purpose: 4-methacryloyloxyethyl trimellitate anhydride/methyl methacrylate-tri-n-butyl borane (4-META/MMA-TBB) resin is used for indirect restorations. We aimed to evaluate effects of immersion in 4-META/MMA-TBB-activated liquid on the bond strength of root canal dentin. Materials and methods: We used freshly extracted single-rooted human teeth. After decoronation, each root was vertically sectioned into halves; their dentin walls were polished and flattened. The control group underwent dentin treatment with Green Activator. The immersion group was treated with Green Activator and Teeth Primer and immersed in 4-META/MMA-TBB-activated liquid. After bonding the resin blocks with Super-Bond, microtensile bond strength (μTBS) tests were performed (n = 6), and fracture surfaces were analyzed. Before surface treatment, dentin was immersed in a sodium fluorescein solution for 3 h, and resin blocks were bonded with Super-Bond with rhodamine B as in the bond strength test. The bonded cross section was observed using confocal laser scanning microscopy (CLSM). Results: μTBS was significantly higher in the immersion group than in the control group (61.5 [51.3–66.7] vs. 33.0 [20.4–57.8] MPa; P < 0.05). Fracture mode analysis showed that, compared with the control group, the immersion group had a significantly lower rate of adhesive failure at the dentin interface and a significantly higher rate of cohesive failure in Super-Bond (P < 0.01). CLSM showed a water droplet-like accumulation of fluorescein dye above the hybrid layer in the control group, not in the immersion group. Conclusion: Immersion in a 4-META/MMA-TBB-activated liquid inhibited water exudation from the root canal dentin and improved the bond strength

Correlation of Serum CPR to Plasma Glucose Ratio with Various Indices of Insulin Secretion and Diseases Duration in Type 2 Diabetes

Evaluating insulin secretion ability and sensitivity is essential to establish an appropriate treatment for patients with type 2 diabetes. The serum C-peptide response (CPR) level is used to evaluate the quantity of endogenous insulin secretion. However, the serum CPR level alone cannot indicate insulin-secretion ability or insulin sensitivity, because plasma glucose levels influence endogenous insulin secretion and vice versa.The CPR index, a ratio of serum CPR level to plasma glucose concentration when measured simultaneously, was previously reported to be a useful marker to determine the necessity of insulin treatment in patients with type 2 diabetes, but the reasons are unknown. The aim of this study was to clarify which factors affect the CPR index in patients with type 2 diabetes. Totally, 121 subjects were included in this study; all participants were hospitalized for type 2 diabetes. On the day after admission, we calculated the CPR index from each patient's fasting blood sample and a blood sample taken 2 hours after breakfast (the postprandial sample). A detailed medical history was taken from each patient to establish the disease duration. The degree of diabetic retinopathy judged by an ophthalmologist was obtained from patients' medical records. An oral glucose tolerance test and a glucagon load test were performed after the fasting plasma glucose level decreased to 130 mg/dl, and indices of insulin secretion and sensitivity were calculated.Fasting and postprandial CPR indices were moderately correlated with total endogenous insulin secretion after oral glucose load and with the CPR level after glucagon load, insulin sensitivity, composite index, and the reciprocal index of homeostasis model assessment (HOMA-R-1). Furthermore, there was a weak but significant correlation between the postprandial CPR index and the duration of diabetes. The postprandial CPR index was inversely correlated with the degree of diabetic retinopathy, which is known to be associated with the duration of hyperglycemia. Our data clearly shows that the CPR index is a useful parameter to reflect the degree of impaired glucose tolerance