Correlation between thermodynamical stabilities of metal borohydrides and cation electronegativites: First-principles calculations and experiments

The thermodynamical stabilities for the series of metal borohydrides M(BH₄)n (M=Li, Na, K, Cu, Mg, Zn, Sc, Zr, and Hf; n=1–4) have been systematically investigated by first-principles calculations. The results indicated that an ionic bonding between Mⁿ⁺ cations and [BH₄]⁻ anions exists in M(BH₄)n, and the charge transfer from Mⁿ⁺ cations to [BH₄]⁻ anions is a key feature for the stability of M(BH₄)n. A good correlation between the heat of formation ΔHboro of M(BH₄)n and the Pauling electronegativity of the cation ϰP can be found, which is represented by the linear relation, ΔHboro=248.7ϰP–390.8 in the unit of kJ/mol BH₄. In order to confirm the predicted correlation experimentally, the hydrogen desorption reactions were studied for M(BH₄)n (M=Li, Na, K, Mg, Zn, Sc, Zr, and Hf), where the samples of the later five borohydrides were mechanochemically synthesized. The thermal desorption analyses indicate that LiBH₄, NaBH₄, and KBH₄ desorb hydrogen to hydride phases. Mg(BH₄)₂, Sc(BH₄)₃, and Zr(BH₄)₄ show multistep desorption reactions through the intermediate phases of hydrides and/or borides. On the other hand, Zn(BH₄)₂ desorbs hydrogen and borane to elemental Zn due to instabilities of Zn hydride and boride. A correlation between the desorption temperature Td and the Pauling electronegativity ϰP is observed experimentally and so ϰP is an indicator to approximately estimate the stability of M(BH₄)n. The enthalpy change for the desorption reaction, ΔHdes, is estimated using the predicted ΔHboro and the reported data for decomposed product, ΔHhyd/boride. The estimated ΔHdes show a good correlation with the observed Td, indicating that the predicted stability of borohydride is experimentally supported. These results are useful for exploring M(BH₄)n with appropriate stability as hydrogen storage materials

Mixed adenoneuroendocrine carcinoma of the esophagogastric junction: a case report

Abstract Background Mixed adenoneuroendocrine carcinoma (MANEC) is a tumor of the gastrointestinal tract that contains both exocrine and endocrine components, with each component exceeding 30% of the total tumor area. Because MANECs are exceedingly rare, no therapeutic strategies have been established yet. Case presentation An 81-year-old man was referred to our hospital with a 5-month history of dysphagia. Esophagogastroduodenoscopy revealed an ulcerated mass in the lower thoracic esophagus, extending up to the esophagogastric junction (33 to 40 cm from the incisors). The initial biopsy diagnosis was adenocarcinoma. Computed tomography revealed no evidence of lymph node or distant metastasis. The patient was treated by thoracoscopic esophagectomy with three-field lymph node dissection and gastric tube reconstruction via a posterior mediastinal approach, under the diagnosis of esophagogastric junctional cancer (T3N0M0, stage IIA). Histopathological examination revealed two distinct components, namely, a neuroendocrine carcinoma component and an adenocarcinoma component, and the patient was diagnosed as having mixed adenoneuroendocrine carcinoma (MANEC). He presented with liver metastasis 6 months after the surgery. Thereafter, the tumor became even more aggressive, and the patient died 8 months after the surgery. Conclusions We report a patient with MANEC of the esophagogastric junction. Close attention should be paid to such patients, as MANEC can be a highly aggressive tumor, showing rapid progression. In the treatment of MANEC, it is necessary to carefully consider the pathological features in each individual case

Guidelines for Developing Amide-Based Hydrogen Storage Materials

An effective method for developing amide-based high-performance hydrogen storage materials is to prepare appropriate combinations of amides and hydrides. We have proposed that a mixture of an amide with a low decomposition temperature and a hydride showing rapid reaction to ammonia would be an appropriate combination. According to this proposal, the mixture of Mg(NH 2 ) 2 (Mg amide) and LiH (Li hydride) was investigated. The dehydriding temperature of the mixture of Mg(NH 2 ) 2 and 4ÁLiH is lower than that of the mixture of LiNH 2 (Li amide) and 2ÁLiH. A method for preventing ammonia release is increasing the LiH ratio in the mixtures, which results in a reduction in the amount of desorbed hydrogen. The homogeneous dispersion between Mg(NH 2 ) 2 and LiH might be also an important factor for preventing ammonia release

Usefulness of three‐dimensional thoracoscope for prone position thoracoscopic esophagectomy improves mediastinal lymph node dissection and prognosis for esophageal cancer

Abstract Objectives This study aimed to assess the superiority of 3D flexible thoracoscope against 2D thoracoscope for lymph node dissection (LND) and prognosis for prone‐position thoracoscopic esophagectomy (TE) in esophageal cancer. Methods Three hundred and sixty‐seven esophageal cancer patients who underwent prone‐position TE with 3‐field LND between 2009 and 2018 were evaluated. 2D and 3D thoracoscope was used in 182 (2D group) and 185 cases (3D group), respectively. Short‐term surgical outcomes, numbers of retrieved mediastinal lymph node (LN), and rates of LN recurrence were compared. Risk factors for mediastinal LN recurrence and long‐time prognosis were also evaluated. Results No differences in postoperative complications were observed between the groups. The numbers of retrieved mediastinal LN were significantly higher, and the rates of LN recurrence were significantly lower in the 3D group compared to 2D group. Use of 2D thoracoscope was a significant independent factor of middle mediastinal LN recurrence by multivariable analysis. Survival was compared by cox regression analysis, and the 3D group had a significantly better prognosis than the 2D group. Conclusions Prone position TE using 3D thoracoscope may improve the accuracy of mediastinal LND and prognosis without increasing postoperative complications for esophageal cancer

Multimodal Treatment Strategies to Improve the Prognosis of Locally Advanced Thoracic Esophageal Squamous Cell Carcinoma: A Narrative Review

Esophageal cancer is the seventh most common malignancy and sixth most common cause of cancer-related death globally. Esophageal squamous cell carcinoma (ESCC) with aortic or tracheal invasion is considered unresectable, and has an extremely poor prognosis; its standard treatment is definitive chemoradiotherapy (dCRT). In recent years, induction chemotherapy (ICT) has been reported to yield high response rates for locally advanced ESCC, and the efficacy and safety of ICT followed by conversion surgery (CS) have been investigated. Multimodal treatment, combining surgery with induction chemoradiotherapy (ICRT) or ICT, is necessary to improve ESCC prognosis. CS is generally performed for locally advanced ECC after ICRT or ICT when tumor downstaging is achieved, although its prognostic benefit remains controversial. The Japan Clinical Oncology Group (JCOG) has conducted a three-arm phase III randomized controlled trial (JCOG1510) to confirm the superiority of DCF (docetaxel, cisplatin, and 5-fluorouracil) ICT, over conventional dCRT, among patients with initially unresectable ESCC. In recent years, researchers have reported favorable outcomes of induction therapy followed by CS and salvage surgery, after dCRT or systemic immunochemotherapy. In this review, we will describe the latest developments in the multimodal treatment including chemotherapy, CRT, surgery, and immunotherapy, which may improve oncological and survival outcomes for patients with cT4 ESCC