Multi-parallax views synthesis for three-dimensional light-field display using unsupervised CNN.

Multi-view applications have been used in a wide range, especially Three-Dimensional (3D) display. Since capturing dense multiple views for 3D light-field display is still a difficult work, view synthesis becomes an accessible way. Convolutional neural networks (CNN) has been used to synthesize new views of the scene. However, training targets are sometimes difficult to obtain, and it views are very difficult to synthesize at arbitrary positions. Here, an unsupervised network of Multi-Parallax View Net (MPVN) is proposed, which can synthesize multi-parallax views for 3D light-field display. Existing parallax views are re-projected to the target position to build input towers. The network is operated on these towers, and outputs a color tower and a selection tower. These two towers yield the final output image by per-pixel weight summing. MPVN adopts end-to-end unsupervised training to minimize prediction errors at existing positions. It can predict virtual views at any parallax position between existing views in a high quality. Experimental results demonstrate the validation of our proposed network, and SSIM of synthetic views are mostly over 0.95. We believe that this method can effectively provide enough views for 3D light-field display in the future work.

Synergistic Effects of Selenophene and Extended Ladder-Type Donor Units for Efficient Polymer Solar Cells.

Two pairs of polymer donor materials based on indacenodithiophene (IDT) and indacenodithieno[3,2-b]thiophene (IDTT) as the donor units are synthesized. Thiophene or selenophene is introduced as the π-bridge units and electron-deficient fluorine-substituted quinoxaline is used as acceptor unit. Selenophene-containing polymers PIDT-DFQ-Se and PIDTT-DFQ-Se show redshifted absorption and narrower bandgaps. Combined with IDTT donor unit, PIDTT-DFQ-Se shows the highest absorption coefficient. Both the IDTT unit and selenophene unit have positive effects on the hole mobilities, making PIDTT-DFQ-Se the highest one. The best power conversion efficiency of 7.4% is obtained from devices based on PIDTT-DFQ-Se:[6,6]-phenyl C71 butyric acid methyl ester (PC71 BM) with a Jsc of 12.6 mA cm-2 , a Voc of 0.89 V, and a fill factor (FF) of 0.66.

Clinical application of the dissection of the preperitoneal space without electrocoagulation in laparoscopic transperitoneal inguinal hernia repair throughout of the whole process.

Introduction: The dissection of the preperitoneal space is performed using a monopolar instrument to prevent bleeding in laparoscopic transabdominal preperitoneal hernia repair (TAPP). It may also cause energy injuries and nerve damage. Aim: To assess the effectiveness and safety of dissection of the preperitoneal space without electrocoagulation (DPSWE) in TAPP throughout the process. Material and methods: A retrospective analysis of data of 134 patients was made. The electrocoagulation group (EG) relied on monopolar instruments. In the non-electrocoagulation group (NEG) mainly scissors were used without electrocoagulation. The patients were followed for up for 3 months. Intraoperative and postoperative conditions and other complications were observed. Results: The VAS scores in the NEG were lower than those in the EG (p < 0.05). The operation time in the NEG was shorter than that in the EG (p < 0.05). Hospitalization expenses, scrotal seroma formation, and rupture of hernia sac in the NEG were lower than those in the EG (p < 0.05). The intraoperative bleeding volume above 20 ml in the NEG was higher than that in the EG. There was no significant difference in the incidence of postoperative bleeding, vas deferens injury, intestinal injury, surgical site infection, length of hospital stay, urinary retention and hernia recurrence in the NEG and the EG (p > 0.05). There was no significant difference in the incidence of surgical site infections (SSIs) in the NEG and the EG. Conclusions: DPSWE is effective and safe. DPSWE may reduce postoperative pain and have no significant increase in postoperative bleeding.

Feasibility of laparoscopic indirect inguinal hernia repair with lateral umbilical fold covering internal inguinal ring combined with patch repair.

Introduction: For an indirect inguinal hernia (IIH), it is a challenge to repair the internal inguinal ring (IIR) with self-tissue reconstruction in laparoscopic repair. Aim: To evaluate the efficacy and safety of covering the IIR with the lateral umbilical fold (LUF) combined with patch repair in laparoscopic indirect inguinal hernia repair. Material and methods: Patients with IIH treated by trans-abdominal preperitoneal (TAPP) hernia repair at the Department of General Surgery, Shanghai Public Health Clinical Centre between September 2019 and March 2021 were retrospectively analyzed. In group I (n = 57) the LUF was overturned and sutured to cover the IIR under a laparoscope and subsequently repaired with a patch. In group II (n = 62), the IIR was not covered by the LUF but only repaired with a self-gripping mesh. Results: We noted a longer suture time in group I than in group II. Although the LUF was covered after suturing, no significant difference in postoperative pain was observed between the two groups. However, significant differences in surgery time and hospitalization cost (p < 0.05) were found. One case of recurrence was observed in group II. Conclusions: The LUF can be used in IIH to cover the IIR and is a feasible approach. The LUF covering the IIR has no significant difference in pain.

Modulation of charge transport through single-molecule bilactam junctions by tuning hydrogen bonds.

Bilactam derivatives with different side groups were synthesized and the twisting angle tuning effect induced by the intramolecular hydrogen bond on the charge transport through their single-molecule junctions was investigated. Molecules with strong intramolecular hydrogen bonds exhibited twice higher conductance because of the reduced dihedral twisting, which was reversible with the addition of hydrogen bond destroying solvent. Our findings reveal that the presence of intramolecular hydrogen bonds promotes the planarization of the molecular structure without additional transmission channels, offering a new strategy for controlling molecular switches via tuning the molecular twisting.

Ladder-Type Dye with Large Transition Dipole Moment for Solvatochromism and Microphase Visualization.

A large transition dipole moment is usually pursued by strategies of twisted intramolecular charge transfer (TICT) or planar intramolecular charge transfer (PICT) to obtain obvious Stokes shifts and dramatic color changes with tuning of polarities. However, both strategies have their drawbacks and suffer from fluorescence quenching in solid states. Herein, a ladder-type molecule ISOAA-H with an intramolecular hydrogen bond is designed, which undergoes intramolecular charge transfer and proton shift to harvest a large transition dipole moment under light irradiation. Thanks to its out-of-plane side chains, the intermolecular π-π stacking of backbones is prohibited and solid emission is generated. ISOAA-H exhibits outstanding solvatochromic behavior with polarity changes of solvents or polymer matrixes and is successfully used to detect the microphase separation of polymer blends. These results indicate that a strategy combining the advantages of TICT and PICT is established for environment-sensitive dyes used in both solution and solid state.