Precision CT­guided marking with India ink and microcoils for laparoscopic resection of a lateral lymph node recurrence of rectal cancer: A case report.

Although rarely used in laparoscopic surgery, computed tomography (CT)-guided marking is useful for targeting small lesions. The present study describes the performance of laparoscopic resection with preoperative CT-guided marking for lateral lymph node recurrence of rectal cancer. A 48-year-old man underwent laparoscopic low anterior resection with D3 lymph node dissection for rectal cancer (postoperative diagnosis, stage IIIb). Postoperative adjuvant chemotherapy was then administered. Solitary lymph node recurrence was observed in the left lateral region after 6 months. Systemic chemotherapy reduced the size of the metastatic lymph nodes; however, 3.5 years after the surgery, the diameter increased by 10 mm, and laparoscopic resection was thus planned. Because the target lesion was small and located deep in the pelvis, preoperative CT-guided marking was performed with India ink injection and embolization microcoil implantation. The markers were clearly identified and the lesion was successfully resected with adequate margins. The approach described in the present study is thus considered potentially useful for the detection of small lesions.

[Ascending colon cancer with submucosal tumor-like morphology arising near ileal valve lipohyperplasia:a case report].

An 89-year-old man was diagnosed with a submucosal tumor suspected to be a lipoma and was followed up for 6 years. The patient was admitted to the hospital because of increased tumor size and morphological changes despite negative bioptic findings. The lesion was diagnosed as an advanced adenocarcinoma of the ascending colon (cT3N0M0, cStage IIa). Laparoscopic-assisted right hemicolectomy with D3 lymph node dissection was performed. Pathological diagnosis of a surgically resected specimen revealed adenocarcinoma with lipohyperplasia (pT3N2aM0, pStage IIIb). Reports of colon cancer accompanied by colonic lipomas or lipohyperplasia are limited. This case showed an interesting submucosal tumor-like morphology because the cancer developed at the base of the lipohyperplasia and grew and spread below it.

Treatment strategy for lymph node metastasis of hepatocellular carcinoma using an ICG navigation system: a case report.

BACKGROUND: Since indocyanine green (ICG) accumulates selectively in hepatocellular carcinoma (HCC) cells, it can be used to detect metastatic lesions. Lymph node metastasis of HCC is rarely observed, both simultaneously and metachronously. Therefore, it is sometimes difficult to identify metachronous lymph nodes during salvage surgery because of prior surgery. Herein, we report a case in which lymph node metastasis of HCC was successfully resected using an ICG navigation system. CASE PRESENTATION: The patient was a 62-year-old man who had undergone radical liver resection for HCC 8 years ago. During surveillance, contrast-enhanced computed tomography (CT) revealed a mass in the hepatic hilum. Various diagnostic modalities suggested that the patient had a solitary metastatic lymph node of HCC, and extirpation of the tumor was planned. Intraoperative ICG fluorescence imaging allowed surgeons to clearly identify the target lesion. Histopathologically, the tumor was confirmed to be a lymph node metastasis of HCC. The patient's postoperative course was uneventful, and he remains alive without recurrence 2 years after the second surgery. CONCLUSION: Intraoperative navigation surgery by ICG fluorescence imaging was useful for the safe resection of extrahepatic metastasis of HCC in a complicated situation.

A rare case of inflammatory myofibroblast tumor of the stomach successfully treated by inverted laparoscopic and endoscopic cooperative surgery.

BACKGROUND: An Inflammatory myofibroblastic tumor (IMT) is a rare intermediate malignancy characterized by myofibroblast proliferation and inflammatory cell infiltration. Various organs are the primary sites of origin. However, primary tumors originating in the stomach tend to be extremely rare, making the diagnosis difficult. Herein, we present a case of IMT originating in the stomach that was effectively managed using inverted laparoscopic endoscopic cooperative surgery (LECS). CASE PRESENTATION: A 47-year-old male who was admitted to the hospital because of a submucosal tumor that was discovered during upper gastrointestinal endoscopy. The diameter of the tumor was approximately 20 mm. A KIT-negative gastrointestinal stromal tumor was suspected based on the biopsy findings. Therefore, partial resection of the stomach was performed using inverted laparoscopic and endoscopic cooperative surgery. Histopathological examination revealed collagen fiber proliferation from the submucosal layer to the muscular layer, accompanied by infiltration of spindle-shaped cells, lymphocytes, and numerous inflammatory cells. Immunohistochemistry results were positive for SMA and negative for CD34, desmin, and c-kit. IgG4-positive cells were observed with an IgG4/IgG ratio > 50%, and specific nuclei were positive for ALK. Therefore, IMT was diagnosed. This condition may be difficult to diagnose both before and after surgery because of its rarity and submucosal tumor-like morphology. CONCLUSION: When a submucosal tumor originating in the stomach is observed, IMT should be considered. Partial resection of the stomach with LECS and immunohistochemical diagnosis may be useful.

Laparoscopic surgery for rectal cancer with a coexisting Retzius shunt and inferior mesenteric arteriovenous malformation: A case report.

A coexisting short-circuit from the inferior mesenteric vein (IMV) to the inferior vena cava, known as a Retzius shunt, and arteriovenous malformation (AVM) of the inferior mesentery are extremely rare conditions. We encountered a case of rectal cancer with coexisting Retzius shunt and inferior mesenteric AVM successfully treated with laparoscopic surgery. Contrast computed tomography (CT) in a 62-year-old man with rectal cancer showed multiple dilated veins at the mesenterium of the descending sigmoid colon. These dilated veins were connected between the IMV and the left renal vein. A diagnosis of Retzius shunt was made, and laparoscopic low anterior resection with lymph node dissection was performed. A pathological examination of the colonic mesenterium revealed AVM communicating with the dilated IMV and Retzius shunt. The preoperative evaluation of aberrant vessels by three-dimensional CT is particularly useful for patients with vascular malformations to ensure safe laparoscopic surgery.

Activating a [FeFe] Hydrogenase Mimic for Hydrogen Evolution under Visible Light.

Inspired by the active center of the natural [FeFe] hydrogenases, we designed a compact and precious metal-free photosensitizer-catalyst dyad (PS-CAT) for photocatalytic hydrogen evolution under visible light irradiation. PS-CAT represents a prototype dyad comprising π-conjugated oligothiophenes as light absorbers. PS-CAT and its interaction with the sacrificial donor 1,3-dimethyl-2-phenylbenzimidazoline were studied by steady-state and time-resolved spectroscopy coupled with electrochemical techniques and visible light-driven photocatalytic investigations. Operando EPR spectroscopy revealed the formation of an active [FeI Fe0 ] species-in accordance with theoretical calculations-presumably driving photocatalysis effectively (TON≈210).

Ferroelectric columnar assemblies from the bowl-to-bowl inversion of aromatic cores.

Organic ferroelectrics, in which the constituent molecules retain remanent polarization, represent an important topic in condensed-matter science, and their attractive properties, which include lightness, flexibility, and non-toxicity, are of potential use in state-of-the-art ferroelectric devices. However, the mechanisms for the generation of ferroelectricity in such organic compounds remain limited to a few representative concepts, which has hitherto severely hampered progress in this area. Here, we demonstrate that a bowl-to-bowl inversion of a relatively small organic molecule with a bowl-shaped π-aromatic core generates ferroelectric dipole relaxation. The present results thus reveal an unprecedented concept to produce ferroelectricity in small organic molecules, which can be expected to strongly impact materials science.

Continuous Phase Transition without Gap Closing in Non-Hermitian Quantum Many-Body Systems.

Contrary to the conventional wisdom in Hermitian systems, a continuous quantum phase transition between gapped phases is shown to occur without closing the energy gap Δ in non-Hermitian quantum many-body systems. Here, the relevant length scale ξ≃v_{LR}/Δ diverges because of the breakdown of the Lieb-Robinson bound on the velocity (i.e., unboundedness of v_{LR}) rather than vanishing of the energy gap Δ. The susceptibility to a change in the system parameter exhibits a singularity due to nonorthogonality of eigenstates. As an illustrative example, we present an exactly solvable model by generalizing Kitaev's toric-code model to a non-Hermitian regime.

Heterobimetallic triple-decker complexes derived from a dianionic aromatic stannole ligand.

A neutral heterobimetallic triple-decker stannole complex was prepared by the reaction of an anionic ruthenocene bearing a stannole dianionic ligand with [Rh(cod)Cl]2 (cod = 1,5-cyclooctadiene), and the resulting Ru-Rh complex exhibits an electronic property different from those of the corresponding Ru-Ru and Rh-Rh complexes. The Ru-Rh complex can be decomposed in ionic liquids to metal nanoparticles.

Disodium Benzodipyrrole Sulfonate as Neutral Hole-Transporting Materials for Perovskite Solar Cells.

Hole-transporting material (HTM) is an indispensable constituent in organic electronic devices, generally comprising a donor/dopant combination. We report that a disodium salt of substituted benzo[1,2- b:4,5- b']dipyrrole bearing two racemic alkanediylsulfonate anion side chains (BDPSOs) serves as a neutral, nonhygroscopic, dopant-free HTM for lead perovskite (MAPbI3) solar cells. These organic/inorganic hybrid molecules are useful for tunable orbital level and controllable solubility. A fluorinated BDPSO has an energy level matched with MAPbI3, affording an inverted-structure solar cell that performs with 17.2% efficiency with minimal hysteresis. The solar cell devices fabricated using BDPSOs showed remarkable storage and operational stability.

Parity-time-symmetric quantum critical phenomena.

Synthetic non-conservative systems with parity-time (PT) symmetric gain-loss structures can exhibit unusual spontaneous symmetry breaking that accompanies spectral singularity. Recent studies on PT symmetry in optics and weakly interacting open quantum systems have revealed intriguing physical properties, yet many-body correlations still play no role. Here by extending the idea of PT symmetry to strongly correlated many-body systems, we report that a combination of spectral singularity and quantum criticality yields an exotic universality class which has no counterpart in known critical phenomena. Moreover, we find unconventional low-dimensional quantum criticality, where superfluid correlation is anomalously enhanced owing to non-monotonic renormalization group flows in a PT-symmetry-broken quantum critical phase, in stark contrast to the Berezinskii-Kosterlitz-Thouless paradigm. Our findings can be experimentally tested in ultracold atoms and predict critical phenomena beyond the Hermitian paradigm of quantum many-body physics.

Synthesis and reactivity of a ruthenocene-type complex bearing an aromatic π-ligand with the heaviest group 14 element.

An anionic ruthenocene derived from a dilithioplumbole complex was prepared. In the complex, the plumbole ligand coordinates a ruthenium atom in an η5-fashion, similar to the cyclopentadienyl ligand in ferrocene. The ruthenocene that has the aromatic π-ligand with the heaviest group 14 element reacted with electrophiles to afford the plumbole complexes wherein the plumbole ligands show deviation from planarity, in contrast to the planar plumbole ring in the anionic ruthenocene. The bent angles of the plumbole ligands are dependent on the substituents on the lead atoms. Cyclic voltammetry measurements revealed that the plumbole complexes are oxidized more easily than the corresponding stannole complexes.

Triphosphasumanene Trisulfide: High Out-of-Plane Anisotropy and Janus-Type π-Surfaces.

A triphosphasumanene trisulfide was designed and synthesized as an out-of-plane anisotropic π-conjugated molecule. Incorporating three anisotropic phosphine sulfide moieties into a sumanene skeleton induced a cumulative anisotropy with a large dipole moment (12.0 D), which is aligned in perpendicular direction with respect to the π-framework and more than twice as large as those of conventional out-of-plane anisotropic molecules. In the crystal, the molecules align to form columnar structures, in which electron-rich and electron-deficient sides of the π-framework face each other. The interactions between the electron-rich surfaces, which contain three sulfur atoms, and Au(111) were examined by X-ray photoelectron spectroscopy.

Efficient Synthesis of 1,4-Bis-heteroatom-substituted Tetraselanylbenzenes via 1,4-Dilithiation of Hexaselanylbenzene and Investigation on Their Electronic Properties.

We successfully synthesized mono- and bis-substituted polyselanylbenzenes 3 and 5 via mono- and dilithiation of hexakis(phenylselanyl)benzene (1), respectively. Introduction of various heteroatom functionalities into hexaselanylbenzene changed the electronic properties dependent on the σ-symmetric circular orbitals that were formed by the interactions between neighboring heteroatoms. In the cyclic voltammetry and theoretical studies on bis-heteroatom-substituted benzenes 5, the extent of the interactions in the circular orbitals with σ-symmetry affected the stability of the cationic species of 5. This study would give insight into the molecular design for new σ-delocalized systems and inspire the development of tuning electronic properties of benzene derivatives by σ-type orbital interactions derived from heteroatom functionalities.

Benzodipyrrole-based Donor-Acceptor-type Boron Complexes as Tunable Near-infrared-Absorbing Materials.

Benzodipyrrole-based donor-acceptor boron complexes were designed and synthesized as near-infrared-absorbing materials. The electron-rich organic framework combined with the Lewis acidic boron co-ordination enabled us to tune the LUMO energy level and the HOMO-LUMO gap (i.e.,the absorption wavelength) by changing the organic acceptor units, the number of boron atoms, and the substituents on the boron atoms.

The Chemistry of Heterasumanenes.

Our studies on the synthesis of heterasumanenes, where benzylic carbon atoms of the sumanene are replaced by heteroatom functionalities, are summarized. Starting from triphenylene, repetitive lithiation at a bay position followed by introduction of silylene or germylene units provided the first trisila- and trigermasumanenes with no substituents on the skeletal carbon atoms. The synthesis of a trisilasumanene bearing six butoxy groups on the skeletal carbon atoms was also accomplished by our original sila-Friedel-Crafts reaction. A heterasumanene bearing three different heteroatom functionalities was also prepared from triphenylenothiophene by a sequential lithiation method, even though protecting groups were necessary to prevent lithiation at the α-carbon atoms of the dibenzothiophene unit. Structural analysis and optical properties of the novel heterasumanenes are also described.

Synthesis of π-extended dibenzophospholes by intramolecular radical cyclization and their properties.

Intramolecular radical cyclization of phosphine oxides (R(1)R(2)P(O)H) induced by radical generators affords the corresponding dibenzophosphole oxides in excellent yields. By applying this method, linearly π-extended ladder-type dibenzophosphole oxides were successfully synthesized.

Integer quantum Hall state in two-component Bose gases in a synthetic magnetic field.

We study two-component (or pseudospin-1/2) Bose gases in a strong synthetic magnetic field. Using exact diagonalization, we show that a bosonic analog of an integer quantum Hall state with no intrinsic topological order appears at the total filling factor ν=1+1 when the strengths of intracomponent and intercomponent interactions are comparable with each other. This provides a prime example of a symmetry-protected topological phase in a controlled setting of quantum gases. The real-space entanglement spectrum of this state is found to be comprised of counterpropagating chiral modes consistent with the edge theory derived from an effective Chern-Simons theory.

The first observation of electroluminescence from di(2-naphthyl)disilene, an Si=Si double bond-containing π-conjugated compound.

Air-stable, room-temperature emissive di(2-naphthyl)disilene, protected by the bulky 1,1,3,3,5,5,7,7-octaethyl-s-hydrindacen-4-yl (Eind) groups, can emit light in an organic light-emitting diode, thus providing the first experimental demonstration of electroluminescence from the heavy group 14 unsaturated compounds.

Forced symbiosis between Synechocystis spp. PCC 6803 and apo-symbiotic Paramecium bursaria as an experimental model for evolutionary emergence of primitive photosynthetic eukaryotes.

Single-cell green paramecia (Paramecium bursaria) is a swimming vehicle that carries several hundred cells of endo-symbiotic green algae. Here, a novel model for endo-symbiosis, prepared by introducing and maintaining the cells of cyanobacterium (Synechocystis spp. PCC 6803) in the apo-symbiotic cells of P. bursaria is described.