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In this paper, approaches for the realization of high-resolution periodic structures with gap sizes at sub-100 nm scale by two-photon polymerization (2PP) are presented. The impact of laser intensity on the feature sizes and surface quality is investigated. The influence of different photosensitive materials on the structure formation is compared. Based on the elliptical geometry character of the voxel, the authors present an idea to realize high-resolution structures with feature sizes less than 100 nm by controlling the laser focus position with respect to the glass substrate. This investigation covers structures fabricated respectively in the plane along and perpendicular to the major axis of voxel. The authors also provide a useful approach to manage the fabrication of proposed periodic structure with a periodic distance of 200 nm and a gap size of 65 nm.

In a phase 2 study in patients with metastatic renal cell carcinoma, overall survival was associated with T-cell responses against IMA901, a vaccine consisting of ten tumour-associated peptides. In this phase 3 trial, we aimed to determine the clinical effect of adding IMA901 to sunitinib, the standard first-line treatment in metastatic renal cell carcinoma with postulated favourable immunomodulatory effects. The IMPRINT study is an open-label, randomised, controlled, phase 3 trial done at 124 clinical sites in 11 countries. HLA-A*02-positive patients (aged ≥18 years) with treatment-naive, histologically confirmed metastatic or locally advanced (or both) clear-cell renal cell carcinoma were randomly assigned (3:2) to receive sunitinib plus up to ten intradermal vaccinations of IMA901 (4·13 mg) and granulocyte macrophage colony-stimulating factor (75 μg), with one dose of cyclophosphamide (300 mg/m2) 3 days before the first vaccination, or to receive sunitinib alone. Sunitinib (50 mg) was given orally once daily, with each cycle defined as 4 weeks on treatment followed by 2 weeks off treatment, until progression of disease as determined by the investigator, death, or withdrawal of consent. Block randomisation (block size five) was done centrally using an interactive web response system, stratified by prognostic risk, geographical region, and previous nephrectomy. Patients and investigators were not masked to treatment allocation. The primary endpoint was overall survival from randomisation until death of any cause as determined by the investigator, analysed by intention to treat. This study is registered with ClinicalTrials.gov, number NCT01265901. Between Dec 22, 2010, and Dec 15, 2012, we screened 1171 patients, of whom 339 were randomly assigned to receive sunitinib plus IMA901 (n=204) or sunitinib monotherapy (n=135). Patients had a median follow-up of 33·27 months (IQR 29·92–35·64). Median overall survival did not differ significantly between the groups (33·17 months [95% CI 27·81–41·36] in the sunitinib plus IMA901 group vs not reached [33·67–not reached] in the sunitinib monotherapy group; hazard ratio 1·34 [0·96–1·86]; p=0·087). 116 (57%) of 202 patients in the sunitinib plus IMA901 group and 62 (47%) of 132 in the sunitinib group had grade 3 or worse adverse events, the most common of which were hypertension, neutropenia, and anaemia in both groups, and mild-to-moderate transient injection-site reactions (eg, erythema, pruritus) were the most frequent IMA901-related side-effect in the sunitinib plus IMA901 group. Serious adverse events leading to death occurred in four (2%) patients (one respiratory failure and circulatory collapse [possibly related to sunitinib], one oesophageal varices haemorrhage [possibly related to sunitinib], one cardiac arrest [possibly related to sunitinib], and one myocardial infarction) and eight (6%) patients in the sunitinib group (one case each of renal failure, oesophageal varices haemorrhage, circulatory collapse, wound infection, ileus, cerebrovascular accident [possibly treatment related], and sepsis). IMA901 did not improve overall survival when added to sunitinib as first-line treatment in patients with metastatic renal cell carcinoma. The magnitude of immune responses needs to be improved before further development of IMA901 in this disease is indicated. Immatics Biotechnologies.

Special integrated photonic surface structures composed of a dielectric semicircle ridge and a dielectric block placed on a metal substrate are proposed for the investigation of surface plasmon polariton (SPP) reflection and transmission effects. A fabrication method called microscope projection photolithography was employed for the preparation of the structures. Leakage radiation microscopy was applied for the excitation and observation of surface plasmon polaritons (SPPs). It was observed that SPPs exhibit a remarkable decrease in intensity when impinging onto the rectangular dielectric block. Nevertheless, the transmitted wave out of the dielectric block was always observable. The propagation behavior of both the reflected waves at two boundaries (air/dielectric and dielectric/air) and the transmitted wave inside the dielectric block were demonstrated for different SPP incident conditions. The variation of the angles of reflection and transmission with respect to the incident angle was analytically and experimentally investigated. An agreement between the calculated results and the experimental results was obtained. Our findings might allow for novel applications in sensing and analytics once the structures will be functionalized.

The advancement of micro- and nanostructuring techniques in optics is driven by the demand for continuous miniaturization and the high geometrical accuracy of photonic devices and integrated systems. Here, UV-LED projection photolithography is demonstrated as a simple and low-cost approach for rapid generation of two-dimensional optical micro- and nanostructures with high resolution and accuracy using standard optics only. The developed system enables the projection of structure patterns onto a substrate with 1000-fold demagnification. Photonic devices, e.g., waveguides and microring resonators, on rigid or flexible substrates with varied geometrical complexity and overall structure dimensions from the nanometer to centimeter scale were successfully prepared. In particular, high-resolution gratings with feature sizes down to 150 nm and periods as small as 400 nm were realized for the first time by this approach. Waveguides made of doped laser active materials were fabricated, and their spontaneous emission was detected. The demonstrated superior performance of the developed approach may find wide applications in photonics, plasmonics, and optical materials science, among others.

The unique optical properties of nanoparticles are highly sensitive in respect to particle shapes, sizes, and localization on a sample. This demands for a fully controlled fabrication process. The use of femtosecond laser pulses to generate and transfer nanoparticles from a bulk target towards a collector substrate is a promising approach. This process allows a controlled fabrication of spherical nanoparticles with a very smooth surface. Several process parameters can be varied to achieve the desired nanoparticle characteristics. In this paper, the influence of two of these parameters, i.e. the applied pulse energy and the laser beam shape, on the generation of Si nanoparticles from a bulk Si target are studied in detail. By changing the laser intensity distribution on the target surface one can influence the dynamics of molten material inducing its flow to the edges or to the center of the focal spot. Due to this dynamics of molten material, a single femtosecond laser pulse with a Gaussian beam shape generates multiple spherical nanoparticles from a bulk Si target. The statistical properties of this process, with respect to number of generated nanoparticles and laser pulse energy are investigated. We demonstrate for the first time that a ring-shaped intensity distribution on the target surface results in the generation of a single silicon nanoparticle with a controllable size. Furthermore, the generated silicon nanoparticles presented in this paper show strong electric and magnetic dipole resonances in the visible and near-infrared spectral range. Theoretical simulations as well as optical scattering measurements of single silicon nanoparticles are discussed and compared.

We address optical amplification properties of quantum nanoparticles of the cadmium selenide/cadmium sulfide (CdSe/CdS) material system with different dimensionality of spatial confinement. CdSe/CdS core/shell quantum dots (QDs), core/shell quantum rods (QRs) and 5 monolayer thick core/crown nanoplatelets (NPLs) at ambient temperature are considered, exhibiting 0D, 1D and 2D spatial confinement dimensionality of the electronic system, respectively. Continuous films of all these nanoparticles are synthesised, and amplified spontaneous emission (ASE) spectra are measured under femtosecond pumping at wavelengths of 400 nm and 800 nm, respectively. The lowest threshold is found for NPLs and the highest for QDs, demonstrating the influence of the rod-like and plate-like CdS structures. To emphasize this effect, ASE is demonstrated also in CdSe/CdS QRs and NPLs under nanosecond pumping at 355 nm in the same material films. The amplification has been achieved without use of any feedback structure, emphazising the efficiency of the antenna effect. The pumping threshold fluences for NPLs and QRs are observed to be similar, but no ASE is observed in QDs up to the damage threshold of the nanoparticle layers. The length variation investigation with nanosecond pumping resulted in the gain coefficients of 29 cm −1 and 37 cm −1 for QRs and NPLs, respectively.

Silicon nanoparticles with sizes of a few hundred nanometres exhibit unique optical properties due to their strong electric and magnetic dipole responses in the visible range. Here we demonstrate a novel laser printing technique for the controlled fabrication and precise deposition of silicon nanoparticles. Using femtosecond laser pulses it is possible to vary the size of Si nanoparticles and their crystallographic phase. Si nanoparticles produced by femtosecond laser printing are initially in an amorphous phase (a-Si). They can be converted into the crystalline phase (c-Si) by irradiating them with a second femtosecond laser pulse. The resonance-scattering spectrum of c-Si nanoparticles, compared with that of a-Si nanoparticles, is blue shifted and its peak intensity is about three times higher. Resonant optical responses of dielectric nanoparticles are characterized by accumulation of electromagnetic energy in the excited modes, which can be used for the realization of nanoantennas, nanolasers and metamaterials. Silicon nanoparticles are of interest for their optical properties, for example, in light scattering. Here, Zywietz et al . achieve the laser printing of silicon nanoparticles on a substrate at predefined positions, and with control over their crystalline phase.

The dispersion relation and propagation of surface plasmons polaritons (SPPs) on nanoporous gold films is experimentally investigated and an increasing red shift of the SPPs is observed with rising porosity. This is caused by a less negative effective dielectric constant of the nanoporous metal films and is predicted by classical Bruggeman or specific two dimensional Maxwell-Garnett effective medium models. The dispersion relation data is supported with leakage radiation microscopy enabling the determination of the propagation length and losses of surface plasmons on these nanoporous films. These results demonstrate how the control of the nanoporosity of metal layers leads to designer plasmons in the visible and near infrared allowing the tuning of the SPP dispersion to match the requirements of certain applications.

The linkages and interactions of scientific disciplines with industry, politics, and society have long been a staple in the history of science, the history of technology, and science studies. However, it is arguable that the impact of this intertwining on the epistemic and social core of scientific disciplines has not yet been sufficiently explored. Chemistry is an ideal case in point, given that it has emerged as one of the largest scientific disciplines while at the same time becoming one of the world’s most powerful technologies. Specifically, chemistry’s power lies in its ability to gain knowledge of the natural world by transforming it, along with the society in which it is embedded. The four contributions to this Focus section all address chemistry’s border permeability, based on its transformative powers; they focus on the feedback mechanisms that transformed chemistry and thereby altered the very concept of a scientific discipline. So successful has this “nonclassical approach” become that, in the opinion of the contributors to this Focus section, it is now both necessary and advisable to study the history of chemistry’s embeddedness and power in science and technology.