PURPOSE: To describe an unprecedented case of transient myopic shift induced by a chemotherapeutic agent, daratumumab. OBSERVATIONS: A 43-year-old emmetropic female with multiple myeloma experienced sudden onset of myopic shift during her first intravenous dose of daratumumab, an increasingly common FDA-approved chemotherapeutic agent. Her myopia was corrected with -4D lenses in both eyes, and the patient reports cessation of symptoms and disuse of lenses after two days. CONCLUSIONS AND IMPORTANCE: A number of medications have been documented to induce transitory myopic shift, and this report now includes daratumumab among such agents. Further clinical findings regarding the mechanism and frequency of daratumumab-induced myopic shift are needed to further develop our understanding of its tangential effect on the eye.

Diamine-appended variants of the metal-organic framework M₂(dobpdc) (M = Mg, Mn, Fe, Co, Zn; dobpdc^4- = 4,4'-dioxidobiphenyl-3,3'-dicarboxylate) exhibit exceptional CO₂ capture properties owing to a unique cooperative adsorption mechanism, and thus hold promise for use in the development of energy- and cost-efficient CO₂ separations. Understanding the nature of thermal transport in these materials is essential for such practical applications, however, as temperature rises resulting from exothermic CO₂ uptake could potentially offset the energy savings offered by such cooperative adsorbents. Here, molecular dynamics (MD) simulations are employed in investigating thermal transport in bare and e-2-appended Zn₂(dobpdc) (e-2 = N-ethylethylenediamine), both with and without CO₂ as a guest. In the absence of CO₂, the appended diamines function to enhance thermal conductivity in the ab-plane of e-2-Zn₂(dobpdc) relative to the bare framework, as a result of noncovalent interactions between adjacent diamines that provide additional heat transfer pathways across the pore channel. Upon introduction of CO₂, the thermal conductivity along the pore channel (the c-axis) increases due to the cooperative formation of metal-bound ammonium carbamates, which serve to create additional heat transfer pathways. In contrast, the thermal conductivity of the bare framework remains unchanged in the presence of zinc-bound CO₂ but decreases in the presence of additional adsorbed CO₂.

We introduce a new, general-purpose, range-separated hybrid van der Waals density functional termed vdW-DF2-ahbr within the nonempirical vdW-DF method [Hyldgaard, et al. J. Phys. Condens. Matter 32, 393001 (2020)JCOMEL0953-898410.1088/1361-648X/ab8250]. It combines a correlation from vdW-DF2 with a screened Fock exchange that is fixed by a new model of exchange effects in the density-explicit vdW-DF-b86r or rev-vdW-DF2 functional [Hamada, Phys. Rev. B 89, 121103(R) (2014)PRBMDO1098-012110.1103/PhysRevB.89.121103]. The new vdW-DF2-ahbr prevents spurious exchange binding and has a small-density-gradient form set from many-body perturbation analysis. It is accurate for bulk as well as layered materials, and it systematically and significantly improves the performance of the present vdW-DFs for molecular problems. Importantly, vdW-DF2-ahbr also outperforms present-standard (dispersion-corrected) range-separated hybrids on a broad collection of noncovalent-interaction benchmark sets, while at the same time successfully mitigating the density-driven errors that often affect the description of molecular transition states and isomerization calculations. vdW-DF2-ahbr furthermore improves on state-of-the-art density-functional-theory approaches by succeeding at challenging problems. For example, it (1) correctly predicts both the substrate structure and the site preference for CO adsorption on Pt(111), (2) it outperforms existing nonempirical vdW-DFs for the description of CO2 adsorption in both a functionalized and in a simple metal-organic framework, and (3) it is highly accurate for the set of base-pair interactions in a model of DNA assembly.

The mutagenic effects of ultraviolet and solar irradiation are thought to be due to the formation of DNA photoproducts, most notably cyclobutane pyrimidine dimers (CPDs) and pyrimidine (6-4) pyrimidone photoproducts ((6-4)PPs). Experimental systems for determining the levels and sequence dependence of photoproduct formation in DNA have often used high doses of short-wave (UVC) irradiation. We have re-assessed this issue by using DNA sequencing technologies and different doses of UVC as well as more physiologically relevant doses of solar irradiation emitted from a solar UV simulator. It has been questioned whether hot alkali treatment can detect (6-4)PPs at all sequence positions. With high UVC doses, the sequence distribution of (6-4)PPs was virtually identical when hot alkali or UV damage endonuclease (UVDE) were used for detection, which appears to validate both methods. The (6-4)PPs form at 5'-TpC and 5'CpC sequences but very low levels are seen at all other dipyrimidines including 5'-TpT. Contrary to expectation, we find that (6-4) photoproducts form at almost undetectable levels under conditions of irradiation for up to five hours with the solar UV simulator. The same treatment produces high levels of CPDs. In addition, DNA glycosylases, which recognize oxidized and ring-opened bases, did not produce significant cleavage of sunlight-irradiated DNA. From these data, we conclude that cyclobutane pyrimidine dimers are at least 20 to 40 times more frequent than any other DNA photoproduct when DNA or cells are irradiated with simulated sunlight.

Cooperative adsorption of gases by porous frameworks, which permits more efficient uptake and removal than the more usual noncooperative (Langmuir-type) adsorption, usually results from a phase transition of the framework. Here we show how cooperativity emerges in the class of metal-organic frameworks mmen-M_{2}(dobpdc) in the absence of a phase transition. Our study provides a microscopic understanding of the emergent features of cooperative binding, including the position, slope, and height of the isotherm step, and indicates how to optimize gas storage and separation in these materials.

The repair enzymes thymine DNA glycosylase (TDG) and methyl-CpG-binding protein 4 (MBD4) remove thymines from T:G mismatches resulting from deamination of 5-methylcytosine. Thymine glycol, a common DNA lesion produced by oxidative stress, can arise from oxidation of thymine or from oxidative deamination of 5-methylcytosine, and is then present opposite adenine or opposite guanine, respectively. Here we have used oligonucleotides with thymine glycol incorporated into different sequence contexts and paired with adenine or guanine. We show that TDG and MBD4 can remove thymine glycol when present opposite guanine but not when paired with adenine. The efficiency of these enzymes for removal of thymine glycol is about half of that for removal of thymine in the same sequence context. The two proteins may have evolved to act specifically on DNA mismatches produced by deamination and by oxidation-coupled deamination of 5-methylcytosine. This repair pathway contributes to mutation avoidance at methylated CpG dinucleotides.

[This corrects the article DOI: 10.1039/C7SC05217K.].

[This corrects the article DOI: 10.1039/C7SC05217K.].

The family of diamine-appended metal-organic frameworks exemplified by compounds of the type mmen-M₂(dobpdc) (mmen = N,N'-dimethylethylenediamine; M = Mg, Mn, Fe, Co, Zn; dobpdc^4- = 4,4'-dioxidobiphenyl-3,3'-dicarboxylate) are adsorbents with significant potential for carbon capture, due to their high working capacities and strong selectivity for CO₂ that stem from a cooperative adsorption mechanism. Herein, we use first-principles density functional theory (DFT) calculations to quantitatively investigate the role of mmen ligands in dictating the framework properties. Our van der Waals-corrected DFT calculations indicate that electrostatic interactions between ammonium carbamate units significantly enhance the CO₂ binding strength relative to the unfunctionalized frameworks. Additionally, our computed energetics show that mmen-M₂(dobpdc) materials can selectively adsorb CO₂ under humid conditions, in agreement with experimental observations. The calculations further predict an increase of 112% and 124% in the orientationally-averaged Young's modulus E and shear modulus G, respectively, for mmen-Zn₂(dobpdc) compared to Zn₂(dobpdc), revealing a dramatic enhancement of mechanical properties associated with diamine functionalization. Taken together, our calculations demonstrate how functionalization with mmen ligands can enhance framework gas adsorption and mechanical properties.