Perovskite/CIGS Spectral Splitting Double Junction Solar Cell with 28% Power Conversion Efficiency.

The highest theoretical efficiency of double junction solar cells is predicted for architectures with the bottom cell bandgap (E g ) of approximately 0.9-1.0 eV, which is lower than that of a typical Si cell (1.1 eV). Cu(In,Ga)(Se,S)2 (CIGS) solar cells exhibit a tunable E g depending on their elemental composition and depth profile. In this study, various CIGS solar cells with E g ranging from 1.02 to 1.14 eV are prepared and a spectrum splitting system is used to experimentally demonstrate the effect of using lower-E g cells as the bottom cell of two-junction solar cells. The four-terminal tandem cell configuration fabricated using a mixed-halide perovskite top cell (E g  = 1.59 eV; stand-alone efficiency = 21.0%) and CIGS bottom cell (E g  = 1.02 eV; stand-alone efficiency = 21.5%) with a 775-nm spectral splitting mirror exhibits an efficiency of 28.0% at the aperture area of 1 cm2.

Ethynyl-linked push-pull porphyrin hetero-dimers for near-IR dye-sensitized solar cells: photovoltaic performances versus excited-state dynamics.

Ethynyl-linked porphyrin hetero-dimers substituted by a series of electron donors, namely, bis(4-methoxyphenyl)amino (BMPA), bis(4-tert-butylphenyl)amino (BTBPA) and 3,6-di-tert-butylcarbazol-9-yl (DTBC) as well as a reference dimer with a non-donor moiety (3,5-di-tert-butylphenyl, DTBP) have been synthesized to systematically investigate the influence of donor introduction on the photovoltaic performances of near-IR dye-sensitized solar cells (DSCs) with these sensitizers incorporated. Despite the expected bathochromic shift and intensification of long-wavelength absorption bands as well as elevated LUMO levels and thus increased electron injection driving forces, the substitution of diphenylamino groups (BMPA and BTBPA) with stronger electron-donating abilities gave rise to surprising mediocrity in the short-circuit photocurrent densities (J(sc)), leading to overall energy conversion efficiencies in the order BMPA (3.94%) < DTBP (4.57%) < BTBPA (4.83%) < DTBC (5.21%). A study of the in situ fluorescent behavior of these sensitizers revealed that for all the sensitizers, excited-state lifetimes were significantly shortened in the simulated DSC environment compared to those in a free solution. BMPA showed the shortest intrinsic in situ lifetime while DTBC showed the longest one. These results were correlated with the photovoltaic performances, which is required for a better understanding and further design of porphyrin array sensitizers.

[Reliability of a less-invasive cardiac output monitor in the perioperative period of a patient with severe dilated cardiomyopathy].

Recently, various less-invasive cardiac output monitors are used for a variety of cases. We used FloTrac system for a patient with severe dilated cardiomyopathy (LVDd/Ds = 75/62 mm, EF = 22%) and recognized its limitation. A 52-year-old woman underwent left partial mastectomy. There were no significant events during the operation. In the ICU, she developed symptoms of low output state, but we could not detect any significant changes on Vigileo Monitor. Arterial pressure-based cardiac output (APCO) measurement with FloTrac is based on the patient's characteristics, blood pressure waveform and basic data stored in Vigileo Monitor. Its accuracy is worse with arterial wave artifact, compromise of the arterial catheter, aortic regurgitation, intense peripheral vasoconstriction, irregular pulse and severe cardiac hypofunction. Thus, its reliability is influenced by various conditions, especially in critically ill patients. FloTrac system is very useful for the management of cardiocirculatory dynamics, but we should be familiar with its limitations.

[Hypertrophic cardiomyopathy].

A 68-year-old woman with severe cardiac dysfunction due to dilated phase of hypertrophic cardiomyopathy was diagnosed with sigmoid cancer and scheduled for high anterior resection. Preoperative left ventricular ejection fraction (EF) was 16% by transthoracic echocardiography. After placement of an epidural catheter at the T12-L1 interspace, and artery catheters in the left radial artery for invasive blood pressure monitoring and in the right femoral artery for stand-by IABE general anesthesia was induced by midazolam, fentanyl and sevoflurane, and maintained with sevoflurane. Analgesia was obtained by epidural administration of 1% lidocaine and 0.2% ropivacaine. A central venous catheter was placed in the right internal jugular vein through which dobutamine was infused throughout the operation. Cardiac function monitored by transesophageal echocardiography showed EF of 9% just after insertion. After arbitrary administration of phenylephrine and landiolol, the operation and anesthesia were completed without serious problems. However, congestive heart failure worsened on postoperative day 2, and was improved by increasing dobutamine and by administration of milrinone.