JenLab (Germany)

Machine learning applications in polymer science are often inefficient due to molecular representations that neglect the inherent hierarchical and statistical nature of macromolecules. This work introduces a structure-aware graph convolutional network (GCN) framework that addresses this limitation by treating polymer samples as statistical ensembles. The approach utilizes a hierarchical graph representation where nodes correspond to monomer units and explicitly integrates molecular mass distribution (MMD) data to account for sample dispersity. A key innovation is an ensemble-based training strategy using topologically realistic graphs generated on-demand via an optimized kinetic Monte Carlo simulation. The model's efficacy was validated on a broad range of tasks. On synthetic data, it achieved more than 98% accuracy in classifying complex polymer architectures. When applied to a large experimental dataset, the model predicts glass transition temperatures (Tg) with high accuracy (R2 = 0.89±0.01). Crucially, a fine-tuning experiment demonstrated that the model could successfully learn the physically / chemically grounded relationship between Tg and molar mass by integrating MMD information. This work establishes a robust and physically realistic paradigm for polymer informatics, enabling more accurate property predictions and paving the way for accelerated in silico material design.

To analyze the difference in objective and subjective photic phenomena following virtual implantation of three different presbyopia-correcting diffractive intraocular lens (IOL) designs. The study was conducted at JENVIS Research Germany. A prospective cross-over and double-masked trial design was used. Seventy-four healthy individuals without cataract (age: 18 to 50 years) were enrolled. All participants assessed photic phenomena with three diffractive IOL designs by virtual implantation using the VirtIOL device (10Lens S.L.U), which allows participants to view through the IOL imaged at the iris plane as if it were implanted: IOL A (Tecnis Synergy ZFR00V; J&J Vision), IOL B (AcrySof IQ PanOptix TFNT00; Alcon Laboratories, Inc), and IOL C (AT ELANA 841P; Carl Zeiss Meditec). The size of the starburst and annular light pattern was measured in degrees, and participants were asked about their preference in terms of quality of night vision when comparing by pairs the IOLs. The starburst pattern size was significantly larger with IOL A (5.54 ± 0.62º) compared to the IOLs B (3.82 ± 0.90º, P < .001) and C (3.65 ± 0.57º, P < .001). However, there were no significant differences between IOLs B and C (P = .078). Regarding the induced annular light pattern, no significant differences were found between IOLs (P > .05). In a pairwise short-term comparison of the IOLs using a simulated night scene with a glare source, participant preference was in favor of IOL C (P < .001). IOL A had objectively a significantly larger starburst pattern than the other two. In a short-term comparison, the new trifocal IOL C was significantly preferred in a night driving scene.

Abstract. Long-term and high-precision measurements of the mole fraction of greenhouse gases (GHG), together with their isotopic composition, are of fundamental importance to understand land-atmosphere interactions. Current flask monitoring programs have important information gaps in large regions of the Earth, particularly in the southern hemisphere and in continental tropical regions. Here, we report on the initiation of a monitoring program and the resulting dataset of high-precision GHG measurements at the Amazon Tall Tower Observatory (ATTO), located in the central Amazon region of Brazil. In September 2021, we installed an automated flask sampler designed and built by the Integrated Carbon Observation System (ICOS) to collect air samples in 3-liter flasks at a height of 324 m above ground level. Samples are collected weekly, during a one-hour integration time between 13:00 and 14:00 h local time (17:00–18:00 UTC). The flasks are shipped to Jena, Germany, for analyses of CO2, CO, CH4, N2O, H2, SF6, 13C–CO2, 14C–CO2, 18O–CO2, 13C–CH4, 2H–CH4, O2/N2, and Ar/N2 at the laboratories of the Max Planck Institute for Biogeochemistry (MPI-BGC). Measurements from this monitoring program provide reference information for this site and act as an additional independent quality control for other measurements in the region. The record of SF6 and simulations based on a regional atmospheric transport model suggest that the footprint of the measurements is predominantly from the southeasterly and northeasterly directions. The time series of the different gas species measured in this monitoring program are being made publicly available through the ATTO data portal and the atmospheric flask sampling program of the MPI-BGC.

The first clinical study of two-photon FLIM has been performed in Jena in 2003 on patients suffering from malignant melanoma. NADH has been imaged by time-correlated single photon counting and 80 MHz femtosecond laser excitation. Studies with a tunable Ti:sapphire for NADH/flavins excitation have been conducted on patients suffering from dermatitis, psoriasis, and cancer. Optical metabolic imaging has been also performed on brain during glioma surgery and on volunteers during oxygen inhalation using an ultracompact Er:doped fiber laser. Five astronauts prior and after long-term space flights have been investigated. "Energizing" cosmetics with oxygen scavengers was found to change the ratio free NADH to bound NADH.

Fluorescence Lifetime Imaging (FLIM) in life sciences based on ultrashort laser scanning microscopy and time-correlated single photon counting (TCSPC) started 30 years ago in Jena/East-Germany. One decade later, first two-photon FLIM images of a human finger were taken with a lab microscope based on a tunable femtosecond Ti:sapphire laser. In 2002/2003, first clinical non-invasive two-photon FLIM studies on patients with dermatological disorders were performed using a novel multiphoton tomograph. Current in vivo two-photon FLIM studies on human subjects are based on TCSPC and focus on (i) patients with skin inflammation and skin cancer as well as brain tumors, (ii) cosmetic research on volunteers to evaluate anti-ageing cremes, (iii) pharmaceutical research on volunteers to gain information on in situ pharmacokinetics, and (iv) space medicine to study non-invasively skin modifications on astronauts during long-term space flights. Two-photon FLIM studies on volunteers and patients are performed with multiphoton FLIM tomographs using near infrared femtosecond laser technology that provide rapid non-invasive and label-free intratissue autofluorescence biopsies with picosecond temporal resolution.

Multiphoton tomography (MPT) has become a high-resolution label-free clinical imaging tool to obtain optical skin biopsies for rapid <i>in vivo</i> histology. Here, we report on the novel multimodal multiphoton tomograph MPT compact based on a chiller-free ultracompact 80 MHz femtosecond fiber laser operating at 780 nm. The 360&deg;-measurement head contains the laser head and multiple photon detectors for (i) autofluorescence (AF) imaging, (ii) fluorescence lifetime imaging (FLIM) for optical metabolic imaging (OMI) and melanin detection, (iii) second harmonic imaging (SHG) of collagen, (iv) confocal reflection microscopy (CRM), and (v) white-light imaging (dermoscopy). Preliminary results of an ongoing multicenter clinical study in patients with suspicious pigmented lesions in two hospitals are presented.

This presentation will discuss recent advances in multiphoton microscopy (MPM) as a tool for in-vivo imaging of human skin to evaluate MPM's potential to enhance the diagnostic accuracy of skin diseases and guide effective treatment.

Recent translation of multiphoton microscopy to clinical practice raises the possibility of high-resolution in-vivo histology of skin. This is of special interest for cancer diagnostics, because early stages of basal cell carcinomas (BCCs) and malignant melanomas (MM) can be imaged. The novel label-free non-invasive process, called multiphoton tomography (MPT), would reduce the time from consultation to treatment. MPT is a nonlinear laser scanning microscopy technique that features high three-dimensional resolution and label-free molecular contrast. Several endogenous tissue components can be visualized, including collagen (through second-harmonic generation), NAD(P)H, FAD, keratin, melanin, porphyrins, and elastin fibers (through two-photon excited fluorescence). Furthermore, fluorescence lifetime imaging (FLIM) can be employed to detect inflammation sites in patients suffering from dermatitis and chronic wounds. The add-on module CARS (Coherent Anti-Stokes Raman Spectroscopy) provides information on the lipid and water distribution. Multimodal MPT is performed in high-tech hospitals in Europe (e.g. Charite/Germany), China, Russia (e.g. Medical Academy, Nizhny Novgorod), Australia (e.g. Princess Alexandra Hospital, Brisbane) and United States (e.g. Beckman Laser Institute and Medical Clinic UCI, Irvine, and University of Illinois at Urbana-Champaign).

Stem cells and 'induced pluripotent stem cells' (iPS cells) attract considerable attention in medicine. So far, iPS cells which morphologically and functionally resemble embryonic stem cells have been generated by means of viruses through the reprogramming of somatic cells for research purposes. Typically, optical techniques such as light microscopy in combination with fluorescent markers are applied, sometimes accompanied with fluorescence-activated cell sorting (FACS), for the characterization and isolation of both tissue-specific stem and iPS cells. Nowadays, modern laser-based techniques such as nonlinear multiphoton microscopy and optical transfection using femtosecond lasers are used for iPS and stem cell imaging as well as for virus-free optical reprogramming.

Multiphoton tomography (MPT) is a novel label-free clinical imaging method for non-invasive tissue imaging with high spatial (300 nm) and temporal (100 ps) resolutions. In vivo optical histology can be realized due to the nonlinear excitation of endogenous fluorophores and second-harmonic generation (SHG) of collagen. Furthermore, optical metabolic imaging (OMI) is performed by two-photon autofluorescence lifetime imaging (FLIM). So far, applications of the multiphoton tomographs DermaInspect and MPTflex were limited to dermatology. Novel applications include intraoperative brain tumor imaging as well as cornea imaging. In this work we describe two-photon imaging of ex vivo human corneas unsuitable for transplantation. Furthermore, the cross-linking (CXL) process of corneal collagen based on UVA exposure and 0.1 % riboflavin was studied. The pharmacokinetics of the photosensitizer could be detected with high spatial resolution. Interestingly, an increase in the stromal autofluorescence intensity and modifications of the autofluorescence lifetimes were observed in the human corneal samples within a few days following CXL.