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We demonstrate a polarization rotator integrated at the output of a GaAs waveguide producing type I second harmonic generation (SHG). Form-birefringent phase matching between the pump fundamental transverse electric (TE) mode near 2.0 µm wavelength and the signal fundamental transverse magnetic (TM) mode efficiently generates light at 1.0 µm wavelength. A SiN waveguide layer is integrated with the SHG device to form a multifunctional photonic integrated circuit. The polarization rotator couples light between the two layers and rotates the polarization from TM to TE or from TE to TM. With a TE-polarized 2.0 µm pump, type I SHG is demonstrated with the signal rotated to TE polarization. Passive transmission near 1.0 µm wavelength shows ∼80% polarization rotation across a broad bandwidth of ∼100 nm. By rotating the signal polarization to match that of the pump, this SHG device demonstrates a critical component of an integrated self-referenced octave-spanning frequency comb. This device is expected to provide crucial functionality as part of a fully integrated optical frequency synthesizer with resolution of less than one part in 1014.

Laser frequency combs, with their unique combination of precisely defined spectral lines and broad bandwidth, are a powerful tool for basic and applied spectroscopy. Here, we report offset-free, mid-infrared frequency combs and dual-comb spectroscopy through supercontinuum generation in silicon-on-sapphire waveguides. We leverage robust fabrication and geometrical dispersion engineering of nanophotonic waveguides for multi-band, coherent frequency combs spanning 70 THz in the mid-infrared (2.5 μm–6.2 μm). Precise waveguide fabrication provides significant spectral broadening with engineered spectra targeted at specific mid-infrared bands. We characterize the relative-intensity-noise of different bands and show that the measured levels do not pose any limitation for spectroscopy applications. Additionally, we use the fabricated photonic devices to demonstrate dual-comb spectroscopy of a carbonyl sulfide gas sample at 5 μm. This work forms the technological basis for applications such as point sensors for fundamental spectroscopy, atmospheric chemistry, trace and hazardous gas detection, and biological microscopy.

We propose and experimentally demonstrate a photonic routing architecture that can efficiently utilize the space of multi-plane (3D) photonic integration. A wafer with three planes of amorphous silicon waveguides was fabricated and characterized, demonstrating < 3 × 1 0 − 4 dB loss per out-of-plane waveguide crossing, 0.05 ± 0.02 dB per interplane coupler, and microring resonators on three planes with a quality factors up to 8.2 × 1 0 4 . We also explore a phase velocity mapping strategy to mitigate the cross talk between co-propagating waveguides on different planes. These results expand the utility of 3D photonic integration for applications such as optical interconnects, neuromorphic computing and optical phased arrays.

Epitaxially-grown self-assembled indium nanostructures, or islands, show promise as nanoantennas. The elemental composition and internal structure of indium islands grown on gallium arsenide are explored using Transmission Electron Microscopy (TEM) Energy Dispersive Spectroscopy (EDS). Several sizes of islands are examined, with larger islands exhibiting high (>94%) average indium purity and smaller islands containing inhomogeneous gallium and arsenic contamination. These results enable more accurate predictions of indium nanoantenna behavior as a function of growth parameters.

An electronic detector of surface plasmon polaritons (SPPs) is reported. SPPs optically excited on a metal surface using a prism coupler are detected by using a close-coupled metal-oxide-silicon (MOS) capacitor. Incidence-angle dependence is explained by Fresnel transmittance calculations, which also are used to investigate the dependence of photo-response on structure dimensions. Electrodynamic simulations agree with theory and experiment and additionally provide spatial intensity distributions on and off the SPP excitation resonance. Experimental dependence of the photoresponse on substrate carrier type, carrier concentration, and back-contact biasing is qualitatively explained by simple theory of MOS capacitors.

Objective: A pre-anesthetic medication that is ideal for pediatric patients undergoing tonsillectomy should alleviate pediatric anxiety, facilitate the smooth induction of anesthesia, and have an analgesic effect for postoperative care. This study compared the effectiveness of an oral combination of midazolam and ketamine (MK) with an oral combination of chloral hydrate and meperidine (CM) as premedication in pediatric patients undergoing tonsillectomy. Methods: This double-blind clinical trial study was conducted with 68 pediatric patients scheduled to undergo tonsillectomy. The participants were randomly allocated into two groups: the CM group, which received oral premedication of 50 mg/kg chloral hydrate and 1.5 mg/kg meperidine, and the MK mixture group, which received oral premedication of 0.5 mg/kg midazolam and 5 mg/kg ketamine. Various parameters such as separation anxiety, agitation during emergence from anesthesia, postoperative pain, postoperative nausea, and vomiting, as well as respiratory depression within a 6-hour period following anesthesia, were carefully recorded and observed. Results: There were no differences between the two groups in terms of separation anxiety (p>0.05) and post-surgery pain scores (p=0.12). Regarding postoperative agitation, there were significantly more patients in an awake but calm state in the CM group than in the MK (44% vs. 17.64%, p=0.01). The incidence of nausea and vomiting was lower in the CM than in the MK group (47% vs. 76.5%, p=0.02). Conclusion: This study shows that an oral mixture of CM is more suitable as pre-anesthetic medication in pediatric patients undergoing tonsillectomy than a MK.

Ureteral stent migration should be considered a rare complication of urologic procedures. We report a 69-year-old woman diagnosed with ureteral stent migration two weeks after undergoing percutaneous nephrolithotomy while she was symptom-free. The stent passed through the heart and extended to the superior vena cava and right brachiocephalic vein. After excluding thrombus formation, the stent was retrieved using an endovascular approach. Stent migration to the superior vena cava while being asymptomatic is extremely rare. Considering this complication is crucial to prevent consequent fatal events. This case report highlights this rare complication of ureteral stent placement and reviews its management.

Diabetes is one of the most rapidly growing health problems globally, and researchers working hard to develop novel efficient therapies against it. In this regard, hydrazine carboximidamide has a great deal of attention owing to its diverse biological activities. Herein, a new series of N, N-disubstituted hydrazine carboximidamide derivatives was designed, synthesized, and assessed for their antidiabetic activity. Docking studies were performed to initially evaluate the binding of the designed compounds to the target enzyme. It was found that all of the pivotal ligand-enzyme interactions, including the interactions with Glu205/Glu206 aminoacids were observed in docking studies. The molecular dynamic analysis showed that the antidiabetic activity of the newly developed compounds may be implemented through the inhibition of dipeptidyl peptidase 4 (DPP-4), an important target that involves enhancing insulin release and suppressing glucagon discharge from the pancreas. The target molecules were synthesized practically and all the newly-developed chemical structures were confirmed via spectrophotometric methods, including IR, LC-MS, 1H NMR, and 13C NMR techniques. Finally, the in-vivo studies were carried out to confirm the results obtained from the docking and molecular dynamics studies. Compounds 6b and 6d demonstrated improved glucose tolerance through oral glucose tolerance tests in NMRI mice (at a dose of 10 mg/kg). Furthermore, prolonged administration of compounds 6b and 6d to diabetic Wistar rats for 14 days led to a noteworthy reduction in blood levels of glucose, akin to the effects observed with sitagliptin, a standard diabetes medication.

Objective: Anthracycline administration in children is associated with cardiac dysfunction. Speckle-tracking echocardiography (STE) can detect subclinical cardiac damage that may go undetected by conventional two-dimensional (2D) echocardiography. This study aims to investigate medium-term anthracycline cardiotoxicity using STE and determine a safer administrable level of anthracyclines (ACs). Methods: This observational case–control study enrolled 37 healthy controls and 78 pediatric cancer survivors who received chemotherapy. The patients were divided into two groups: cardiotoxic received (CR) and cardiotoxic free (CF). Data on segmental longitudinal strain (LS), global LS (GLS), and 2D echocardiographic parameters were collected after a drug-free period of at least one year. Results: A total of 115 children with a mean age of 108 ± 55 months, of whom 66% were males, were included in the study. Both the groups of cancer survivors exhibited significantly reduced GLS compared to healthy controls (CR vs. controls, P = 0.001; CF vs. controls, P = 0.013), but no significant difference in left ventricular ejection fraction (LVEF) was observed (P = 0.75). Overall, cancer survivors treated with ACs demonstrated a significant reduction in strain in 10 left ventricular segments, particularly in the basal segments (P < 0.05). Among CR patients, those with impaired GLS (n = 43, GLS worse than −21.9) had significantly higher mean age and cumulative anthracycline dose compared to CR patients with normal GLS (age, P = 0.024; anthracycline dosage, P = 0.036). Using an anthracycline cutoff of 223 mg/m2 resulted in a higher detection rate (49% vs. 25%) and fewer missed cases (51% vs. 74%) compared to the 360 mg/m2 anthracycline cutoff. Conclusion: Childhood cancer survivors demonstrate significantly reduced GLS while preserving a normal LVEF, which does not differ significantly from reference values of healthy children. The reduction in strain appears to be associated with higher anthracycline doses and older age. Lowering the anthracycline threshold to 223 mg/m2 may improve the predictability of a decline in cardiac function using strain imaging at medium-term follow-up.

BACKGROUND: Despite the beneficial effects, RBC transfusion can be associated with infectious and non-infectious complications in critically ill patients. OBJECTIVES: Investigate current RBC transfusion practices and their effect on the clinical outcomes of patients in intensive care units (ICUs). DESIGN: Retrospective observational study SETTING: Three mixed medical-surgical adult ICUs of a large academic tertiary hospital PATIENTS AND METHODS: From March 2018 to February 2020, all adult patients admitted to medical or surgical ICU. Patients who received one or more RBC transfusions during the first month of ICU admission were included in the “transfusion” group, while the remaining patients were assigned to the “non-transfusion” group. MAIN OUTCOME MEASURES: Mortality and length of ICU and hospital stay. SAMPLE SIZE: 2159 patients RESULTS: Of 594 patients who recieved transfusions, 27% of patients received red blood cell (RBC) products. The mean pre-transfusion hemoglobin (Hb) level was 8.05 (1.46) g/dL. There was a significant relationship between higher APACHE II scores and ICU mortality in patients with Hb levels of 7–9 g/dL (OR adjusted=1.05). Also, ICU mortality was associated with age (OR adjusted=1.03), APACHE II score (OR adjusted=1.08), and RBC transfusion (OR adjusted=2.01) in those whose Hb levels were >9 (g/dL). CONCLUSION: RBC transfusion was associated with an approximately doubled risk of ICU mortality in patients with Hb>9 g/dL. High APACHE II score and age increase the chance of death in the ICU by 8% and 3%, respectively. Hence, ICU physicians should consider a lower Hb threshold for RBC transfusion, and efforts must be made to optimize RBC transfusion practices. LIMITATIONS: Single-center and retrospective study.

Abstract Background Myelolipoma is a benign neoplasm of the adrenal cortex, composed of fat and hematopoietic cells. Although myelolipoma is benign, differentiation from adrenocortical cancer may be difficult. The presence of adrenal and extra-adrenal myelolipomas simultaneously is sporadic, making it a challenging case, especially when the preoperative diagnosis is ambiguous. Case presentation A 65-year-old man was referred to our clinic due to a mass in the adrenal fossa. In the abdominopelvic computed tomography (CT), a well-circumscribed fat-containing 78 × 61 × 65 mm bi-lobulated mass was reported in the left adrenal fossa. The first differential diagnosis was myelolipoma. The patient was then referred to our clinic for a mass excision. He was asymptomatic and was scheduled to undergo laparoscopic-assisted adrenalectomy. After adrenalectomy and mass dissection, surprisingly, another mass was detected in the retroperitoneal area. The second mass was also dissected. The final diagnosis was myelolipoma for both masses. The patient has been symptom-free for nine months after the operation. Conclusion Simultaneous adrenal and extra-adrenal myelolipoma should be considered as one of the differential diagnoses. However, because this situation is extremely rare, the probability of malignancy should be highly regarded, and we suggest an obsessive approach when approaching this condition. It is essential to manage these cases on a case-by-case basis and tailor the management concerning intraoperative biopsy, the intraoperative appearance of tumors, and the location of extra-adrenal masses.

Abstract Background Tibial plateau fractures (TPF) are uncommon and challenging for orthopedic surgeons with controversial reported outcomes. In this study, we aimed to evaluate the functional outcomes and quality of life (QOL) of patients with surgically treated TPF. Methods A total of 80 consecutive patients and 82 controls participated in this case control study. The patients were all surgically treated in our tertiary center from April 2012 to April 2020. The functional outcome was evaluated using the Western Ontario and McMaster Universities Arthritis Index (WOMAC) scale. Moreover, we used the Short Form 36 health survey (SF-36) health survey to evaluate the QOL. Results No significant difference was observed in the overall mean SF-36 score in the two groups. We found a significant positive correlation between the scores of the SF-36 and WOMAC questionnaires (r = 0.642, p 0.05). Conclusion QoL after TPF is not significantly different from that of a matched control group. Also, neither age nor BMI correlates with the QoL and functional outcome.

In this research, the use of ZnO thin films, as anti-reflective layers of solar cells, is presented. The thin films were synthesized through a sol-gel method and then deposited on a P-N silicon substrate using the spin coating technique. The effect of the ZnO thin films on the efficiency of a solar cell piece was then investigated. To synthesize the ZnO films, zinc acetate dihydrate was used as the precursor, monoethanolamine (MEA) was employed as the stabilizer, and 2-methoxyethanol was used as the solvent. also in order to investigate the effect of concentration of sol-gel solution in formation of ZnO nanoparticles, samples with various concentrations were prepared and after deposition, solar cell piece was fabricated. The ZnO thin films prepared were characterized using X-ray diffraction and field emision-scanning electron microscopy, and a four-point probe was used to measure the surface resistance of the sample. Moreover, to evaluate the electrical properties of the solar cell piece, first, the back and front metal connections of the solar cell were installed using the stencil silk-screen printing method and then a solar simulator was used. The obtained results indicated that the nano-structured ZnO films with hexagonal crystallites and 30-50 nm particle sizes were successfully formed on the silicon substrate. Also, the observations unraveled that the coated ZnO films could act as an anti-reflection films and improved the efficiency of silicon solar cells. In addition, the results showed that the concentration of the sol-gel solution can have a considerable effect on the efficiency of the silicon solar cell.

Abstract Here we sought to determine the relationship between STAT3 activity and Galectin‐3 (Gal‐3) and to investigate the cytotoxic effect of PectaSol‐C Modified Citrus Pectin (Pect‐MCP) as a specific competitive inhibitor of Galectin‐3 (Gal‐3) in combination with Paclitaxel (PTX) to kill the ovarian cancer cell SKOV‐3 multicellular tumor spheroid (MCTS). To this order, SKOV‐3 cells in 2D and 3D cultures were treated with exogenous Gal‐3 for the assessment of STAT3 activity. Two‐way ANOVA main effect and IC50 of each drug Paclitaxel (PTX) and Pect‐MCP or in combination were obtained from MTT assay results. The phosphorylated STAT3 levels, migration, invasion, integrin mRNA and p‐AKTser473 levels were assessed in the absence or presence of each drug alone or in combination. Gal‐3 expression levels were assessed in human serous ovarian cancer (SOC) specimens and its correlation with different integrin mRNA levels was further assessed. Our results showed that Gal‐3 expression level was significantly increased in MCTS compared to monolayer SKOV‐3 cells which triggered STAT3 phosphorylation. Moreover, Pect‐MCP synergized with PTX to kill SKOV3 MCTS through abrogation of STAT3 activity and reduced expression of its downstream target HIF‐1α, reduced integrin mRNA levels, and subsequently decreased AKT activity. There were higher expression levels of Gal‐3 in human high‐grade SOC specimens compared to the normal ovary and borderline SOC which positively and significantly correlated with α5, β2 and β6 integrin mRNA levels. Together, these results revealed for the first time that Pect‐MCP could be considered as a potential drug to enhance the PTX effect on ovarian cancer cells MCTS through inhibition of STAT3 activity.

The effect of feeding greater amounts of byproducts (BP) as a replacement for human-edible (HE) feed ingredients on nutrient intake, chewing activity, rumen fermentation, production performance, human-edible feed conversion efficiency (HeFCE) and net food production (NFP) of high-producing Holstein cows was evaluated. Twelve multiparous Holstein cows (BW = 673 ± 44, DIM = 112 ± 8 d; 48 ± 2.25 kg/d of milk; mean ± SE) were used in a replicated 3 × 3 Latin square design with 28-d periods. Each period consisted of 21 d of adaptation followed by 7 d of data collection. Treatments diets were (DM basis): (1) concentrate containing 26% byproducts (BP26; control); (2) concentrate containing 60% byproducts (BP60); and (3) concentrate containing 95% byproducts (BP95). Alfalfa hay (20% dietary DM) and corn silage (20% dietary DM) were included in all diets. Dietary concentrations of neutral detergent fiber (NDF), non-fiber carbohydrates (NFC), starch and ether extract (EE) were 32.1, 41.0, 26.14 and 3.4% (BP 26); 35.3, 36.0, 22.05 and 4.7% (BP60); and 38.2, 32.0, 17.96 and 6.1% (BP95), respectively (DM basis). Dry matter (22.07 kg/d) and NEL (35.16 Mcal/d) intakes did not differ among treatments. However, ether extract and NDF intakes increased, whereas starch intake decreased linearly as BP ingredients increasingly replaced HE feed ingredients. Eating time was not affected by dietary treatment, but ruminating and total chewing time tended to increase with increasing amounts of BP. Replacing HE with BP ingredients did not affect rumen pH. An increased proportion of BP ingredients in the diet linearly decreased propionate, isobutyrate, isovalerate and valerate concentrations in the rumen and increased acetate concentration and the acetate to propionate ratio. Replacing HE with BP ingredients did not affect milk yield. The yield of 3.5% FCM (39.12, 40.14 and 41.33 kg/d for BP26, BP60 and BP95, respectively) and fat content (2.95, 2.99 and 3.13 % for BP26, BP60 and BP95, respectively) linearly increased. Substituting BP ingredients for HE feed ingredients increased unsaturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, stearic acid, oleic acid and preformed fatty acids but decreased saturated fatty acids, palmitic acid, de novo and mixed fatty acids. Replacing HE with BP feed ingredients increased human-edible efficiency (HeFCE) for crude protein (1.06, 1.66 and 4.14 kg/kg edible for BP26, BP60 and BP95, respectively) and for energy (2.27, 3.62 and 9.22 MJ/MJ edible for BP26, BP60 and BP95, respectively) and also net food production (NFP) for crude protein (0.064, 0.52, and 1.00 kg/d for BP26, BP60, and BP95, respectively) and energy (62.8, 83.0 and 104.7 MJ/d for BP26, BP60 and BP95, respectively). Feeding byproduct-based concentrates instead of human-edible feed ingredients increase human-edible feed conversion efficiency (HeFCE), net food production (NFP) and improved the performance of high-producing Holstein cows.

Objective Electrical low frequency stimulation (LFS) is a new therapeutic method that moderates hyperexcitability during epileptic states. Seizure occurrence is accompanied by some changes in action potential (AP) features. In this study, we investigated the inhibitory action of LFS on epileptiform activity (EA) induced-changes in AP features in hippocampal CA1 pyramidal neurons. Materials and Methods In this experimental study, we induced EA in hippocampal slices by increasing the extracellular potassium (K+) concentration to 12 mM. LFS (1 Hz) was applied to the Schaffer collaterals at different pulse numbers (600 and 900) at the beginning of the EA. Changes in AP features recorded by whole-cell patch clamp recording were compared using phase plot analysis. Results Induction of EA depolarized membrane potential, decreased peak amplitude, as well as the maximum rise and decay slopes of APs. Administration of 1 Hz LFS at the beginning of EA prevented the above mentioned changes in AP features. This suppressive effect of LFS depended on the LFS pulse number, such that application of 900 pulses of LFS had a stronger recovery effect on AP features that changed during EA compared to 600 pulses of LFS. The constructed phase plots of APs revealed that LFS at 900 pulses significantly decreased the changes in resting membrane potential (RMP), peak amplitude, and maximum rise and decay slopes that appeared during EA. Conclusion Increasing the numbers of LFS pulses can magnify its inhibitory effects on EA-induced changes in AP features.

Objective(s): Opioids and cannabinoids are two important compounds that have been shown to influence the activity of magnocellular neurons (MCNs) of supraoptic nucleus (SON). The interaction between opioidergic and cannabinoidergic systems in various structures of the brain and spinal cord is now well established, but not in the MCNs of SON. Materials and methods: In this study, whole cell patch clamp recording of neurons in rat brain slice was used to investigate the effect of acute morphine and cannabinoid administration on spontaneous inhibitory and excitatory spostsynaptic currents (sIPSCs and sEPSCs) in MCNs. Results: Bath application of morphine produced an increase in sEPSCs frequency and a decrease in sIPSCs frequency. In contrast, bath application of URB597 (fatty acid amide hydrolase (FAAH) inhibitor) produced a decrease in sEPSCs frequency but an increase in sIPSCs frequency. WIN55212-2 (cannabinoid receptor agonist) decreased both sIPSCs and sEPSCs frequencies of MCNs. Co-application of morphine and URB597 attenuated the effect of morphine on MCNs. Conclusion: Taken together, these data indicated that at the cellular level, pharmacological augmentation of endocannabinoids could attenuate morphine effects on MCNs.

Background: The memory impairment, obtained from intracerebroventricular (i.c.v.) infusion of streptozotocin (STZ) in rats through activation of oxidative stress, is accepted as sporadic Alzheimer’s disease (AD) model in most experimental studies. Dimethyl sulfoxide (DMSO) as a solvent is widely used in animal studies to have antioxidant effects as well. However, no report is available about DMSO effect on oxidative stress-induced cognition deficit i.e. AD. The present work was designed to assess the effect of chronic treatment of DMSO on STZ-treated rats. Materials and Methods: STZ (3 mg/ kg i.c.v. bilateral with 10 µl volume in either side days 1 and 3) using a single-day version of Morris water maze (MWM). The DMSO (2.5, 5 and 10 %v/v in saline), started from the first day, was infused for 14 days. Results: The chronic administration of DMSO 10% (but not 2.5 and 5%) improved the distance to hidden platform (P

The entorhinal cortex (EC) is one of the earliest affected brain regions in Alzheimer's disease (AD). EC-amyloid pathology induces synaptic failure in the dentate gyrus (DG) with resultant behavioral impairment, but there is little known about its impact on neuronal properties in the DG. It is believed that calcium dyshomeostasis plays a pivotal role in the etiology of AD. Here, the effect of the EC amyloid pathogenesis on cellular properties of DG granule cells and also possible neuroprotective role of L-type calcium channel blockers (CCBs), nimodipine and isradipine, were investigated. The amyloid beta (Aβ) 1-42 was injected bilaterally into the EC of male rats and one week later, electrophysiological properties of DG granule cells were assessed. Voltage clamp recording revealed appearance of giant sIPSC in combination with a decrease in sEPSC frequency which was partially reversed by CCBs in granule cells from Aβ treated rats. EC amyloid pathogenesis induced a significant reduction of input resistance (Rin) accompanied by a profound decreased excitability in the DG granule cells. However, daily administration of CCBs, isradipine or nimodipine (i.c.v. for 6 days), almost preserved the normal excitability against Aβ. In conclusion, lower tendency to fire AP along with reduced Rin suggest that DG granule cells might undergo an alteration in the membrane ion channel activities which finally lead to the behavioral deficits observed in animal models and patients with early-stage Alzheimer's disease.

The results of many studies suggested possible relationship between polymorphism at codons 16 and 27 and development of tolerance to beta-2 adrenoceptor agonist responses as well as disease severity in asthmatic patients. This study was designed to evaluate the effect of polymorphism of beta2 adrenoceptors on response to salmeterol and fluticasone (as inhaled Seretide). Sixty-four patients with either mild or moderate-severe asthma were evaluated in this study. A four-week therapy with Seretide was conducted in moderate-severe asthmatics. The respiratory parameters and asthma score (based on GINA guidelines) were measured before and after run in period. Blood samples were genotyped at codons 16 and 27. No significant difference was observed in genotypes neither at codon 16 nor at codon 27 between mild and moderate-severe asthma groups. However, Patients in Arg/Arg (n = 8) category showed significant improvement in asthma control parameters and lung function compared with Arg/Gly genotype (n =20). These results suggest that genotyping may be useful in some asthmatic patients in order to better tailor asthma treatment plan.

The coupling of radiation emitted on semiconductor inter-band transitions to resonant optical-antenna arrays allows for enhanced light–matter interaction via the Purcell effect. Semiconductor optical gain also potentially allows for loss reduction in metamaterials. Here we extend our previous work on optically pumped individual near-surface InGaAs quantum wells coupled to silver split-ring-resonator arrays to wire and square-antenna arrays. By comparing the transient pump-probe experimental results with the predictions of a simple model, we find that the effective coupling is strongest for the split rings, even though the split rings have the weakest dipole moment. The effect of the latter must thus be overcompensated by a smaller effective mode volume of the split rings. Furthermore, we also present a systematic variation of the pump-pulse energy, which was fixed in our previous experiments. [ABSTRACT FROM AUTHOR]