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Fatigue sacral fractures (FSFs) are rare and often misdiagnosed. This study presents a series of FSFs and a meticulous literature review.The present is an 11-year (2010-2021) retrospective observational study. The characteristics of all adult patients with FSF, including demographics, fracture type, treatment, history of fatigue fracture and imaging were evaluated.Eight cases (6 females; 75%), suffering from 12 fractures (4 bilateral cases) with mean age=33.4 years were studied. Two patients (25%) had suffered another fatigue fracture in the past. Mean symptoms' duration prior diagnosis was 8.5 weeks, while mean symptoms' duration after diagnosis was 10.75. In most cases (7; 87.5%), MRI revealed the fracture. According to the Kaeding-Miller classification; five fractures (42%) were grade III, four (33%) IV and three (25%) II. All patients were treated conservatively, with rest and analgesics, while three received vitamin D and calcium. One patient, due to delayed union, was commenced on teriparatide.FSFs are often misdiagnosed; therefore, they should be included in the differential diagnosis for chronic low back-or-hip pain in athletes. History of other fatigue injuries seems to be a predisposing factor. It is of paramount importance to obtain advanced imaging for identifying a FSF.

Introduction:Osteoarthritis (OA) is a leading cause of disability in older adults. The majority of cruciate ligament injuries progress to OA through numerous mechanisms. The aim of this study was to identify the histological changes of cruciate ligaments in OA knees from patients undergoing total knee arthroplasty (TKA) as well as possible correlations with coronal plate deformities and patients’ characteristics. Methods:A total of 50 consecutive patients with knee OA undergoing TKA with posterior stabilized prosthesis were included in the study. Demographics, preoperative range of flexion, the flexion contracture, Visual Analogue Scale (VAS) score, coronal plane deformity, Kellgren and Lawrence radiological degree of OA and Beguin-Locker classification of intraoperative degree of OA were recorded. The histopathological changes evaluated in specimens from both cruciate ligaments included myxoid and mucoid degeneration, chondroid metaplasia and orientation of collagen fibers. Results:A total of 24 males (48%) and 26 females (52%) with a mean age of 71 years (SD 5.93) participated in our study. The mean preoperative duration of pain was 3.62 years (SD 2.2). The K-L scale mean score was 2.60 (SD 0.64) and the mean VAS score 6.38 (SD 1.1). The mean varus deformity was 10.14 degrees (SD 3.7). Knee flexion/flexion contracture were recorded at 95.76±6.183 and 16.14±4.914 degrees, respectively. Intraoperatively, the B-L scale mean score was 2.02 (SD 0.77). Mucoid degeneration in ACL was the most common histopathological feature (15.7%) (SD 12.9), followed by chondroid metaplasia in both ACL and PCL [14.3% (SD12.5) and 14.3% (SD 13.2), respectively]. A negative correlation between BMI and myxoid ACL (p=0.01) as well as between varus deformity and mucoid ACL (p=0.05) was found, while a negative correlation between height and myxoid ACL (p=0.05) has been also revealed. Conclusion:Degeneration of cruciate ligaments is associated with degenerative joint disease and OA should be considered a disease involving the whole joint including ligaments, menisci, synovium and joint capsule. However, the correlation between degeneration of cruciate ligaments and OA is not yet fully understood and more research is needed

A combined method of high-resolution gamma spectroscopy and thermal ionization mass spectroscopy without chemical separation was applied for plutonium assay in pure Pu and U–Pu mixed solutions collected at the Rokkasho Reprocessing Plant, Japan. The relative biases of Pu assay results determined by the combined method to the conventional IDMS are less than 0.01% in the pure Pu and the U–Pu mixed solutions. The combined method can be used as an alternative rapid method for Pu assay as a backup to the conventional IDMS method and K-edge densitometry without any loss of precision and accuracy.

Plutonium(VI) spectrophotometry is a precise analytical method for determining the concentration of plutonium solutions. It is simple and cost-effective to implement in nuclear environments such as glove boxes and hot-cells. Uncertainties were assessed at 0.64% (k = 1) for solutions of 0.150 mg g−1 initially prepared in a glove box. The critical limit of the method was estimated at 0.002 mg g−1 at 99% confidence. The good performances of the technique in the present work are due to a rigorous spectra processing as well as preparation steps conducted by weight control.

Osteoporotic vertebral fractures (OVFs) are considered benign and heal after 8-12 weeks. Nevertheless, up to one third of these patients will have persistent back pain, which may be complicated with neurologic deficit or paraplegia A unique unusual case of delayed onset of neurological complication of an osteoporotic vertebral fracture (OVF) in an elderly patient is reported. The patient presented with paraparesis due to isolated substantial atrophy of the psoas muscle 12 months after the initial fracture. The patient was investigated with imaging and nerve contacted studies. We suggest that psoas muscle atrophy can be determinant clinical sign to diagnose neurological compromise resulting from OVF, even if there is no other clinical indicators of spinal pathology.

Background: Isolated scaphotrapeziotrapezoidal (STT) joint osteoarthritis (OA) is a relatively common condition. Scaphotrapeziotrapezoidal arthrodesis is the traditional treatment, while excisional arthroplasty with the use of flexor carpi radialis (FCR) or polycarbon implants represents a promising alternative surgical management. The present study aims to assess a novel alternative technique of excisional arthroplasty with the use of palmaris longus (PL) tendon as interposition material. Materials: The present research is a retrospective observational study. Patients suffering from symptomatic isolated STT OA, without midcarpal instability and treated with excisional arthroplasty with the use of PL tendon as interposition material, were evaluated. Five patients (two males and three females) with mean age of 63.8 years [standard deviation (SD)=16.9] were included. The mean follow up was 56.4 months (SD=9.8). In order to quantify the clinical results, we used the preoperative and postoperative visual analogue scale (VAS) score at rest and during activity, abbreviated Disabilities of the Arm, Shoulder and Hand (QuickDASH) score and postoperative ROM. Results:The postoperative VAS score at rest and during activity showed a decrease of 86.2% and 62.5%, respectively, when compared to the preoperative one. Regarding postoperative ROM at final follow-up, patients had a mean wrist flexion 71° compared to 78° of the contralateral hand, while the mean extension was found to be 57° compared to 66° of the contralateral side. Conclusions:The evaluated novel technique with the use of PL tendon as interposition material seems to offer satisfying results, while allowing to keep the FCR tendon intact. More studies comparing these techniques are of utmost importance to conclude which is the optimal treatment.

Background: Osteomyelitis caused by Aspergillus spp. is a severe, but rare, clinical entity. However, clear guidelines regarding the most effective medical management have not yet been established. The present study is a literature review of all such cases, in an effort to elucidate epidemiology, as well as the therapeutic management and the infection’s outcome. Methods: A thorough review of all reports of osteomyelitis of the appendicular and the axial skeleton, without the skull and the spine, caused by Aspergillus spp. was undertaken. Data about demographics, imaging techniques facilitating diagnosis, causative Aspergillus, method of mold isolation, antifungal treatment (AFT), surgical treatment, as well as the infection’s outcome were recorded and evaluated. Results: A total of 63 cases of osseous infection due to Aspergillus spp. were identified. The studied population’s mean age was 37.9 years. The most commonly affected site was the rib cage (36.8%). Most hosts suffered immunosuppressive conditions (76.2%). Regarding imaging methods indicating diagnosis, computer tomography (CT) was performed in most cases (42.9%), followed by plain X-ray (41.3%) and magnetic resonance imaging (MRI) (34.9%). The most frequent isolated mold was Aspergillus fumigatus (49.2%). Cultures and/or histopathology were used for definite diagnosis in all cases, while galactomannan antigen test was additionally used in seven cases (11.1%), polymerase chain reaction (PCR) in four cases (6.3%), and beta-d-glucan testing in three cases (4.8%). Regarding AFT, the preferred antifungal was voriconazole (61.9%). Most patients underwent surgical debridement (63.5%). The outcome was successful in 77.5%. Discussion: Osteomyelitis due to Aspergillus spp. represents a severe infection. The available data suggest that prolonged AFT in combination with surgical debridement is the preferred management of this infection, while identification of the responsible mold is of paramount importance.

Introduction Anterior sternoclavicular joint dislocation (SCJ) is a relative rare injury, related to high energy trauma. The objective of the present study is to present a novel suture technique for treatment of anterior SCJ traumatic dislocation and to report clinical outcomes from a small case series undergoing this procedure. Patients and Methods Patients presenting with traumatic anterior SCJ disruption in our institution were eligible to participate. Surgical technique consisted of two bone tunnels drilled in vertical direction from the anterior to the posterior cortex of the manubrium. Analogous to the sternal side of the clavicle, two vertical bone tunnels were drilled from the anterior cortex towards the posterior cortex. A non-absorbable suture was passed though the four holes in a parallel configuration. Then, by pulling the free suture edges the posterior translation of the clavicle was performed. Two additional drill holes, the first in manubrium and the second in clavicle were performed from the anterior cortex to the posterior between the previous bone tunnels. A non-absorbable suture was placed in a simple configuration in order to stabilize the SCJ in the superior–inferior direction. The final follow up was 28.2 months. The mean QuickDASH was used for functional assessment. Results Seven patients (6 males and 1 female) with average age of 34,8 years were included in the present study. Two patients suffered from concomitant medial clavicle fracture. At final follow-up (none of the patients had experienced any symptoms of instability of SCJ, no side-to-side difference was observed, while the Mean QuickDASH score was 4.85. Conclusion The reported technique for SCJ reconstruction in traumatic anterior SCJ dislocations with two sutures has theoretical advantages, since it stabilizes the SCJ in the antero–posterior, as well as the supero- inferior direction. Outcomes from this small case series are favorable. However, more research is desirable to compare different techniques and to conclude to the optimal surgical treatment.

Anterior shoulder dislocations following an epileptic event are considered rare. An extremely rare case of a 41 year old female suffering from bilateral anterior shoulder dislocation with concomitant greater tuberosities fractures after an epileptic seizure is presented. The patient presented to the out-patient orthopaedic clinic due to persistent pain and restriction of shoulders movement, 4 weeks after an epileptic seizure. Clinical examination and radiological evaluation established the diagnosis of bilateral anterior shoulder dislocation with concomitant greater tuberosities fractures. Closed reduction was performed under general anesthesia. There are 12 such cases in the literature, including the present one. Thirty percent of these cases had a delayed diagnosis. It is of paramount importance to have a high clinical suspicion for myoskeletal injuries and especially for shoulder dislocations following an epileptic episode, even in the absence of a traumatic event.

The spine represents an unusual site of pancreatic metastatic disease, while the exact incidence of this metastatic lesion is unclear. An extremely rare case of bone painful blastic metastatic lesion at the fourth thoracic vertebra, as a first manifestation of pancreatic cancer, is reported in the current study. A 54-year-old man was complaining of upper thoracic spinal pain that lasted the previous 4 months. A CT scan revealed a solitary, sclerotic, bone lesion of the body of the fourth thoracic (T4) vertebra, indicating a benign lesion. A consequent MRI scan of the thoracic spine confirmed the sclerotic lesion along with additional findings, such as bone marrow edema of the vertebra and a paraspinal and epidural soft tissue mass. Biopsy of the T4 vertebra lesion revealed metastatic lesion of pancreatic origin. A CT scan of the upper abdomen confirmed the diagnosis. This is a rare case, since the only initial symptom of pancreatic cancer was pain of the upper spine, while the first imaging was misleading, indicating a lesion that was benign in nature.

Objectives: Many countries have implemented quarantines to control the Coronavirus (COVID-19) pandemic spread. The quarantine effects on surgically-treated fractures, operated during this period (March 9th – May 4th) in two public Greek institutions, the “Venizeleion” General Hospital of Crete (VGH) and the “251” Hellenic Air Force General Hospital of Athens (“251” HAFGH) were evaluated and compared with those of the same period of 2019. Materials and methods: This is a retrospective study of a prospectively collected database. Evaluated data included gender, age, and trauma mechanism. Outcomes: A total of 103 patients who had suffered fractures were surgically treated in both institutions during the quarantine period of 2020 compared to 179 during the same period of 2019, showing a reduction of 43% in surgical cases. The mean age of patients treated in 2020 was 72.2 (SD=19.9), as compared to 65.3 (SD=21.5; p-value=0.008) in 2019. There were 70 (68%) elderly patients (>65 years) in 2020 and 103 (57.6%) in 2019. Of all treated fractures, 31% were caused by high energy mechanisms during the explored period of 2020, as compared to 45% in 2019 (p-value=0.019). Conclusions: This is the first study in Europe evaluating the effect of COVID-19 quarantine on surgically treated fractures. The findings showed a significant decline in surgically treated fractures, particularly high-energy fractures, along with a significantly higher mean age of patients in 2020 compared to 2019. Low-energy fractures in elderly during quarantine emphasizes the need of prevention measures to minimize their incidence, especially in a time when the health personnel and resources are engaged in the battle against COVID-19.

Objectives: To investigate the differences in distribution of intracapsular and extracapsular hip fractures among genders and age groups treated surgically. Materials and methods: This is a nine-year retrospective cohort study. The type of hip fractures, age, and sex-related as well as overall incidence among 2 430 patients aged over 65, surgically treated at the “Venizeleio” General Hospital of Heraklion, Crete, Greece, were explored and evaluated. Outcomes: Women suffered hip fractures 2.9 times more often than men. The majority of patients hospitalized with hip fracture were above 75 years of age (62.3% in females and 59.3% in males). The proportion of extracapsular and intracapsular fractures were 59.6% and 40.4% in men and 62.7% and 37.2% in women, respectively. Extracapsular-intertrochanteric fractures were found to increase dramatically with age in women (from 52.3% in patients younger than 75 to 58.8% in those older than 75; p-value=0.007), while in men they slightly increased with age (57.7% in patients older than 75, compared to 55.7% in those less than 75; p-value=0.62). Conclusion: The pattern of hip fractures was found to differ between genders and age groups in the present patients’ population. Most likely, these findings reflect differences in the nature and rate of bone loss, and frequency of falling events between males and females. It has become evident that the two main hip fracture types (extracapsular and intracapsular) are distinct clinical entities. Hence, they should be addressed independently in terms of underlying causes and prevention strategies.

The management of spinal metastatic tumors is a matter of increasing clinical importance, as 20-40% of cancer patients have evidence of vertebral metastatic disease at the time of their passing and up to 20% develop neurological symptoms due to epidural spinal cord compression. The treatment of patients with spinal metastases is challenging, albeit palliative, and it requires a multidisciplinary approach. Accurate prediction of life expectancy of patients with cancer is of paramount importance for therapeutic strategy. Prognostication scoring systems were developed to aid clinicians to follow a more objective, safe and evidence-based approach with therapy selection and surgical intervention indications. In this context, the aim of the present review was to briefly discuss the evolution of scoring systems since their introduction in the early 90s until today, their advantages and shortcomings, and the future requirements for personalized scoring in the era of modern oncology.

Background: Spondylodiscitis caused by Aspergillus spp. is a rare but life-threatening clinical entity. However, a consensus on diagnostic criteria and most effective medical management is still missing. The present study is a review of all published cases of spondylodiscitis caused by Aspergillus spp., in an effort to elucidate epidemiology, patients’ characteristics, andand the medical and surgical treatment options and their effectiveness. Methods: A thorough review of all existing spondylodiscitis cases caused by Aspergillus was performed. Data regarding demographics, responsible fungus, time between symptoms’ onset and firm diagnosis, antifungal treatment (AFT), surgical intervention, andand the infection’s outcome were investigated. Results: A total of 118 Aspergillus spondylodiscitis cases, yielding 119 Aspergillus spp. isolates, were identified in the literature. The patients’ mean age was 40.6 years. Magnetic resonance imaging (MRI) (after its introduction) indicated the diagnosis in most cases (66.7%), while definite diagnosis was established through cultures in the majority of cases (73.7%). Aspergillus fumigatus was isolated in most cases (73; 61.3%), followed by Aspergillus flavus (15; 12.6%) andand Aspergillus nidulans and terreus (7; 5.9%, each). The mean time between symptoms’ onset and diagnosis was 5.7 months. Amphotericin B was the preferred antifungal regiment (84 cases; 71.2%), followed by voriconazole (31; 26.3%), and the mean AFT duration was 6.1 months. The final outcome was successful in 93 cases (78.8%). Furthermore, 77 patients (65.3%) underwent surgery. Conclusions: Spondylodiscitis caused by Aspergillus spp. represents a clinical challenge, requiring a multidisciplinary approach. The present review has shown that prolonged AFT has been the standard of care of the studied cases, while surgical treatment seems to play an important role in selected patents.

Acheiropoietos in its current state is a typical Early Byzantine three-aisled timber-roofed basilica with narthex and galleries. During the destructive earthquake of June 20, 1978, the basilica suffered significant damage. In the following years, ambient vibration measurements were performed at the damaged structure before any intervention and main eigenperiods of vibration were calculated. In 1990s, an extensive structural restoration project was undertaken aiming at the provision of diaphragms of controlled shear strength and rigidity at the level of the timber floors and roofs of the galleries. Horizontal steel frames were placed at the perimeter of these diaphragms providing the required diaphragmatic response. The interventions were intended to support the long north and south walls and galleries of the basilica by its stiffer east and west walls against horizontal actions. Within the framework of the present study, the efficiency of the interventions to achieve the desired diaphragmatic response was investigated by measuring the structure’s response to ambient vibration. The in situ measurements and the postprocessing data document that the timber diaphragms are actually behaving as rigid levels. Therefore, it is concluded that the implemented interventions on the basilika assure its proper diaphragmatic function, improving thus successfully its dynamic behavior in future earthquake excitations, according to the redesigned structural approach.

International audience; In this contribution, we present a combined archaeomagnetic and luminescence study of archaeologically dated structures. The investigated area is a ceramic workshop comprising several Early Byzantine kilns. Based on (a) the archaeological–anthropogenic stratigraphy of the site, (b) the structural characteristics of the kilns and (c) the few ceramic findings revealed within their context, the operation of this brick and tile factory is approximately dated between the middle of the fifth century until the first decades of the sixth century AD. Three of the well-preserved workshop kilns have been studied archaeomagnetically. The full vector of the geomagnetic field, accompanied by rock magnetic analyses of the studied material, has been defined. The archaeomagnetic study revealed similar directions among the three kilns indicating and confirming their contemporary use. Additionally, several luminescence measurements were obtained on material from the same kilns. The dating of the site was performed with both methods. The archaeomagnetic dating is convergent with the archaeological estimation only when its upper limit is considered. Concerning the luminescence dating, the calculated ages (corrected for anomalous fading and for the 40K content) with their standard deviations are convergent with the archaeological estimations for the first kiln, while for the other two, the results seem to be incompatible. The possible factors that provoked this divergence are thoroughly discussed.

This paper presents a case study on agent-based simulation concerning the growth of poverty. The aim is to support policy makers and researchers to explore different factors concerning specific localities and policies that affect poverty's nature and growth. The paper presents a rather inclusive model, incorporating characteristics about the local environment, the local economic structure, community institutions and demographic characteristics, together with characteristics of individuals populating the locality. Experimental results show the potential of the constructed model. We also discuss various visualization strategies that will support decision makers to better explore the complexity of the phenomenon and the effectiveness of foreseen policies.

Four-corner fusion is a rational surgical option for the management of degenerative conditions of the wrist. Most related studies have compared four-corner fusion with scaphoid excision or proximal row carpectomy, with a variety of reported results. To enhance the literature, we performed this study to evaluate a series of patients with degenerative conditions of the wrist treated with four-corner fusion using 3 surgical techniques and to discuss the clinical and radiographic outcome of the patients. We retrospectively studied 31 patients (24 men, 7 women; mean age, 43 years; 9 heavy manual laborers) who underwent four-corner fusion of their wrists for degenerative conditions from 2005 to 2015. Internal fixation was done using multiple Kirschner wires (14 patients), headless compressive screws (8 patients), or a circular plate (9 patients). Mean follow-up was 4 years (1–11 years). We evaluated the clinical outcome with the Patient-Rated Wrist Evaluation (PRWE) score and fusion with radiographs. All patients experienced improvement of their pain, function, range of motion and grip strength (p

Introduction Dislocation/subluxation of the Extensor Carpi Ulnaris (ECU) tendon is a rare condition in the general population, but is a common problem among athletes that subject their wrists to forceful rotational movements. Pain and snapping sensation at the dorsoulnar aspect of the wrist especially during supination are the predominant symptoms that often necessitate surgical intervention. Case presentation We present a case of a professional water-polo athlete with recurrent ECU tendon dislocation, in whom a combination of direct repair of the tendon's subsheath and reinforcement with an extensor retinaculum graft led to definitive resolution of her symptoms and resulted in her uneventful return to high-level sport activities 4 months postoperatively. Conclusions The treatment of symptomatic ECU instability is still controversial, especially for acute dislocations. Depending on the type of injury many surgical techniques have been proposed. Combination of direct repair of the tendon's subsheath and reinforcement with an extensor retinaculum graft is a reliable option.

An important issue in a component-based software development process is the supply source of mature, reliable, adaptable and maintainable components. We define as component mining the deliberate, organised and automated process of extracting reusable components from an existing rich software base and present a pattern language used for mining components from programs that are typically executed as non-interactive autonomous processes. We describe the patterns in terms of intent, motivation, applicability, structure, participants, consequences and implementation. Based on the pattern language, we describe the implementation of a set of COM components that encapsulate the Unix filters and an exemplar application that uses them.

Objective. The aim of the present study was to explore the relationship between diabetes mellitus type 2, Obsessive-compulsive disorder (OCD) symptomatology and depressive symptomatology with the metabolic profile of diabetic patients. Methods. One hundred and thirty-one diabetic patients were randomly selected. In the first assessment all participants completed the Zung Self Rating Scale (ZUNG) and the Maudsley O-C Inventory Questionnaire (MOCI). After 1 year, diabetic patients that were initially uncontrolled (n = 31) (HbA1c > 7) were re-evaluated by the same psychometric tools. From those 31 patients, 10 had managed to control their metabolic profile. Results. In the first evaluation MOCI and the sub-scale of slowness were statistically related with the diabetic profile (controlled, HbA1c > 7; uncontrolled, HbA1c > 7), with uncontrolled patients scoring significantly higher on the overall MOCI score and the factor of slowness of MOCI scale (P = 0.028). The analysis revealed a positive association between depressive symptomatology (P = 0.004) and obsessive-compulsive disorder symptomatology (P < 0.001) and the metabolic profile of the patients. In the second evaluation the patients that managed to control their metabolic profile scored lower in both ZDRS and MOCI, although these differences in scores failed to reach significance levels were indicative of a tendency. Conclusions. The present results provide initial evidence that diabetes mellitus type 2 is associated with obsessive-compulsive disorder symptomatology and depressive symptomatology.

Photochemical reactions of technetiumtricarbonyl compounds with neutral phosphorous donor ligands are reported. (C 5 Me 5 )Tc(CO) 3 and (C 5 H 5 )Tc(CO) 3 react with triphenylphosphane to yield (C 5 Me 5 )Tc(CO) 2 (PPh 3 ) ( 3 ) and (C 5 H 5 )Tc(CO) 2 (PPh 3 ) ( 4 ) respectively. 3 and 4 have been isolated and their molecular and crystal structures were determined by single-crystal X-ray diffraction. The crystal structures of the yellow compounds 3 (monoclinic) and 4 (triclinic) are discussed together with their spectroscopic data and are compared with the also determined structure of the homologous rhenium compound (C 5 Me 5 )Re(CO) 2 (PPh 3 ) ( 3a ). Thermal in-situ reaction of irradiated HB(3,5-Me 2 C 3 HN 2 )Tc(CO) 3 with trimethylphosphite (TMP) yields HB(3,5-Me 2 C 3 HN 2 )Tc(CO) 2 (TMP) ( 7 ). The crystal and molecular structure of 7 was determined and and is discussed in comparison with the determined structures of the homologous compounds HB(3,5-Me 2 C 3 HN 2 )Re(CO) 2 (TMP) ( 7a ), and HB(3,5-Me 2 C 3 HN 2 )Mn(CO) 2 (TMP) ( 7b ). The intermediate Re-compound HB(3,5-Me 2 C 3 HN 2 )Re(CO) 2 (THF) ( 8a ) has been also isolated and characterized.

The heterocyclic “half-sandwich”-compounds η5-(Me4C4N)M(CO)3·HNC4Me4 of manganese, technetium and rhenium have been synthesized by reaction of tetramethylpyrrolyl potassium, (Me4C4N)K, with BrM(CO)5(M = Mn, Tc, Re) in THF. The products were isolated and characterized by IR, UV/VIS, EI-MS and 1H-NMR spectroscopy. The crystal and molecular structure of the three compounds were determined by single-crystal X-ray diffraction. The technetium and rhenium compounds crystallize orthorhombic with four molecules per elementary cell. The manganese compound crystallizes monoclinic with eight molecules per elementary cell, which belong to two discrete types of molecules. A tetramethylpyrrolylring is η5-coordinated to the M(CO)3-fragment, and a free tetramethylpyrrole is bonded to the nitrogen atom of the η5-bonded pyrrolylring by a hydrogen-bridged bond.